BG3.2 | Land use, land management, and land cover change (LULCC) and their effects on the Earth system
EDI
Land use, land management, and land cover change (LULCC) and their effects on the Earth system
Co-organized by CL3.2
Convener: Alan Di Vittorio | Co-conveners: Ryan Bright, Gregory Duveiller, Thomas O'Halloran, Julia Pongratz
Orals
| Mon, 28 Apr, 08:30–12:30 (CEST)
 
Room N1, Wed, 30 Apr, 14:00–18:00 (CEST)
 
Room N1
Posters on site
| Attendance Tue, 29 Apr, 10:45–12:30 (CEST) | Display Tue, 29 Apr, 08:30–12:30
 
Hall X1
Orals |
Mon, 08:30
Tue, 10:45
Human activities on land (LULCC) shape climate by altering land-atmosphere fluxes of carbon, water, energy, and momentum. An increasing focus on land-based climate mitigation and adaptation strategies to meet more stringent targets has expanded the range of land management practices considered specifically for their potential to alter terrestrial carbon cycling or mediate favorable environmental conditions. This focus has also called attention to potential tradeoffs between climate-centric aspects of LULCC and its influences on biodiversity, hydrology and other environmental factors. Advancements in modeling and measurement techniques are opening new possibilities to better describe LULCC and its effects on the Earth system at multiple temporal and spatial scales.

This session welcomes all contributions aimed at furthering our understanding of LULCC in the Earth system, including those addressing LULCC effects on carbon, climate, hydrology, and/or biodiversity, and aims to present studies that can inform adoption of appropriate land-based strategies for climate mitigation, adaptation, and ecosystem restoration.

Orals: Mon, 28 Apr | Room N1

The oral presentations are given in a hybrid format supported by a Zoom meeting featuring on-site and virtual presentations. The button to access the Zoom meeting appears just before the time block starts.
Chairpersons: Gregory Duveiller, Julia Pongratz, Ryan Bright
08:30–08:35
Biogeochemical effects of LULCC
08:35–08:55
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EGU25-4303
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ECS
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solicited
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Highlight
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On-site presentation
Karina Winkler, Mohamed Byari, Maximilan Witting, Felix Gulde, and Mark Rounsevell

To achieve net-zero greenhouse gas emissions in the future, carbon dioxide removal (CDR), also known as negative CO2 emissions, is likely to become an essential part of the climate mitigation portfolio. In Germany, land-based CDR options such as bioenergy with carbon capture and storage (BECCS), agroforestry, forest management, and afforestation/reforestation are increasingly being discussed and integrated into potential future scenarios. However, it remains unclear how these options will affect future land use in Germany and what impacts this will have on ecosystem service provision.

Depending on future socioeconomic development and the progression of climate change, Germany can follow different paths for implementing CDR in the land system. We use a set of stakeholder-developed qualitative and quantitative CDR visions and Shared Socioeconomic Pathways (SSPs) combined with climate change scenarios to simulate the future land use change in Germany concerning afforestation/reforestation, forest management, agroforestry, and BECCS. For this, we develop CRAFTY-DE, a new agent-based model of the German land system that integrates a wide range of available land use/cover data and operates at a 1 km² resolution. Here, the demand for ecosystem services drives a range of interrelated land use agents with different productivities and dependencies on changing socio-economic and environmental conditions.

With CRAFTY-DE, we simulate the conditions under which CDR targets can be achieved in the German land system. In particular, we investigate the role of selected policy measures. Our research addresses the following questions: Which scenarios offer favourable conditions for which CDR measures and thus synergies between ecosystem services? How can specific policy measures support this? What are the trade-offs and land use conflicts associated with CDR measures?

Identifying possible pathways of land use change and the resulting synergies and trade-offs associated with CDR will become an important knowledge base for policymakers, industry, and stakeholders regarding the scope for action in the development of land-based CDR in Germany.

How to cite: Winkler, K., Byari, M., Witting, M., Gulde, F., and Rounsevell, M.: Agent-based modelling of alternative futures in the German land system: What are the socioecological impacts of land-based Carbon Dioxide Removal?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4303, https://doi.org/10.5194/egusphere-egu25-4303, 2025.

08:55–09:05
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EGU25-7385
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ECS
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On-site presentation
Danni Zhang, Thomas Gasser, and Bo Zheng

Terrestrial ecosystem carbon dynamics play a critical role in regulating the Earth system's carbon cycle, strongly influenced by atmospheric processes and land management policies. Climate change is transforming carbon cycling within ecosystems and their exchange with the atmosphere, while forest management policies are increasingly recognized as essential nature-based climate solutions. However, the long-term impacts of climate processes and forest management on carbon cycling—spanning historical, present, and future periods—remain poorly understood due to limitations in current modeling frameworks. This uncertainty hinders efforts to optimize forest management strategies and implement effective climate change mitigation measures.

To address these challenges, we employ the state-of-the-art compact Earth system model OSCAR to integrate carbon dynamics predictions from Dynamic Global Vegetation Models (DGVMs) and bookkeeping models. Using the GCB2023 dataset as a historical baseline, we drive the OSCAR model under a range of climate scenarios (i.e., SSP126 and SSP370) and land-use and land-cover change (LULCC) trajectories. Our analysis provides multi-scenario projections of terrestrial carbon fluxes, including regional and biome-specific annual carbon flux estimates through 2100. Additionally, we quantify the inertia of LULCC impacts and evaluate emissions from land-use changes under diverse socio-economic and forest policy pathways, and disentangle the relative contributions of environmental conditions and land-use policies to future carbon dynamics.

Our projections indicate that CO₂ concentrations drive long-term carbon sink trends, while climate variability predominately influences interannual fluctuations. In mid- to high-latitude regions, LULCC carbon balance exhibits minimal sensitivity to forest policies, acting as a modest carbon source or sink. Conversely, in low-latitude regions, robust forest policies are crucial to reversing the carbon source status associated with LULCC. Cumulative emissions from land use can be offset by carbon sinks arising from ecosystem restoration. These findings offer critical insights into the future trajectories of terrestrial carbon cycles and provide a foundation for developing targeted climate change mitigation strategies. Our dataset, which will be updated annually with the latest GCB assessments, serves as a valuable resource for global monitoring, policy evaluation, and strategy optimization.

How to cite: Zhang, D., Gasser, T., and Zheng, B.: Terrestrial Carbon Dynamics through 2100: Projections with OSCAR Highlighting Climate and Land Management Impacts, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7385, https://doi.org/10.5194/egusphere-egu25-7385, 2025.

09:05–09:15
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EGU25-1898
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On-site presentation
Zhangcai Qin, Josep Canadell, Philippe Ciais, Min Chen, Susan Cook-Patton, Tingting Li, Umakant Mishra, Shilong Piao, Pete Smith, Yijie Wang, Wenping Yuan, and Yakun Zhu

Our understanding of regional net carbon flux from land-based ecosystems and land-use changes has been evolving and improving as more data and advanced models become available. However, the size and attribution of carbon sources and sinks related to existing and potential land-use and land-use change (LUC) activities are still often debated, especially in the context of climate change mitigation and carbon neutrality. In this presentation, we aim to convey several key messages derived from our recent findings based on updated data and newly developed models (mechanistic and machine learning-based).   Using a new bookkeeping model (i.e., LUCE), we demonstrate that LUC has contributed to global net CO2 emissions, with forest-related activities (e.g., deforestation, reforestation) dominating changes in carbon fluxes. LUC could shift from a net carbon source to a net carbon sink in some regions with extensive gains in forest area particularly due to reforestation and afforestation. However, upon further examination of future land-use scenarios, we find that the large potential of carbon sequestration estimated from newly grown forests should be scrutinized from both ecological and socioeconomic perspectives. The role of the land sector in the global carbon budget could change over time and space, but an urgently needed positive change (from a carbon source to a sink) relies heavily on what we can and decide to do next.

How to cite: Qin, Z., Canadell, J., Ciais, P., Chen, M., Cook-Patton, S., Li, T., Mishra, U., Piao, S., Smith, P., Wang, Y., Yuan, W., and Zhu, Y.: Exploring land-based ecosystem carbon sources and sinks, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1898, https://doi.org/10.5194/egusphere-egu25-1898, 2025.

09:15–09:25
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EGU25-18466
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ECS
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On-site presentation
Lina Teckentrup, Etienne Tourigny, Florian Wimmer, Markus Donat, Raffaele Bernadello, Isabel Cano Martínez, Francis X. Johnson, Leon Merfort, Stefan Olin, Rüdiger Schaldach, Eise Spijker, and David Wårlind

Carbon dioxide removal (CDR) strategies are critical for climate stabilisation under the Paris Agreement. All current IPCC scenarios that achieve the Paris Agreement’s objectives rely on CDR, and implementing CDR explicit representations into Earth System Models will allow the production of more realistic future scenario projections for CMIP7 and beyond. Here we present results from the LANDMARC project which aims to explore the efficiency of carbon dioxide removal as well as risks associated with land-based mitigation technologies (LMTs). We employ a coupled modeling system consisting of the EC-Earth3-CC Earth System Model with the LPJ-GUESS dynamic global vegetation model, and the LandSHIFT-G land-use model, and simulate five different LMTs, specifically i) fixing carbon in vegetation and soils by afforestation/ reforestation; increasing soil carbon by ii) no/reduced tillage agriculture and iii) combining the substitution of fossil fuels with biofuels and medium to long-term storage of carbon by iv) bioenergy and carbon capture and storage (BECCS) and biochar as well as v) reducing deforestation through agro-forestry and agro-pastoral practices. Based on two different portfolios, assuming an either moderate or high ambition to employ LMTs, we estimate the potential carbon removal through LMTs, and their impact on the average and variability in climate. We find that implementing LMTs has the potential to achieve net-negative emissions before the end of the century, and to reduce the atmospheric CO2 concentration by 47 - 62 ppm depending on the LMT portfolio investigated. The carbon removal is simulated to dampen the global increase in temperature by roughly 0.4°C by the end of the century. While this reduction alone is insufficient to meet the Paris Agreement goals, it highlights the need to invest significantly in both CDR and emissions reductions, which serve as complementary means for achieving climate stabilisation alongside sustainable development goals.

How to cite: Teckentrup, L., Tourigny, E., Wimmer, F., Donat, M., Bernadello, R., Cano Martínez, I., Johnson, F. X., Merfort, L., Olin, S., Schaldach, R., Spijker, E., and Wårlind, D.: Bottom-up estimate of the carbon dioxide removal potential of land-based mitigation technologies using a coupled ESM/ land-use change model framework, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18466, https://doi.org/10.5194/egusphere-egu25-18466, 2025.

09:25–09:35
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EGU25-2311
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ECS
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On-site presentation
Yue He, Shilong Piao, Philippe Ciais, Hao Xu, and Thomas Gasser

China’s commitment to carbon neutrality by 2060 relies on the Land Use, Land-Use Change, and Forestry (LULUCF) sector, with forestation targets designed to enhance carbon removal. However, the exact sequestration potential of these initiatives remains uncertain due to differing accounting conventions between national inventories and scientific assessments. Here, we reconcile both estimates and reassess LULUCF carbon fluxes up to 2100, using a spatially explicit bookkeeping model, state-of-the-art historical data, and national forestation targets. We simulate a carbon sink of −0.24 ± 0.03 Gt C yr−1 over 1994–2018 from past forestation efforts, aligned well with the national inventory. Should the official forestation targets be followed and extended, this could reach −0.35 ± 0.04 Gt C yr−1 in 2060, offsetting 43 ± 4% of anticipated residual fossil CO2 emissions. Our findings confirm the key role of LULUCF in carbon sequestration, but its potential will decline if forestation efforts cease, highlighting the necessity for emission reductions in other sectors to achieve carbon neutrality.

How to cite: He, Y., Piao, S., Ciais, P., Xu, H., and Gasser, T.: Future land carbon removals in China consistent with national inventory, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2311, https://doi.org/10.5194/egusphere-egu25-2311, 2025.

09:35–09:45
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EGU25-5812
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ECS
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On-site presentation
Wei Shan

Land consolidation (LC) is an important land use activity in China. Especially under the background of global climate change and national carbon neutrality strategy, it is particularly important to study the relationship between LC and carbon cycle. Existing studies lack the carbon effects analysis of the whole process and the exploration of low-carbon optimization strategies. Therefore, from the perspective of the whole life cycle, this study applied Life Cycle Assessment (LCA) method to construct a research framework and accounting system for carbon footprint assessment of LC, and then explored the decision-making optimization path of low-carbon LC construction based on the ISM model. Results showed that: (a) The carbon effect of the project area was characterized as carbon sink during the whole life cycle of LC, with the amount of 492tCE. (b) Carbon effect varied among different stages of LC. The Restoration Period (RP) and the Benefit Period (BP) were characterized as carbon sink, while all the other stages were manifested as carbon emission. Among them, as to the carbon emission, the Construction Period (CP) played a decisive role with the most proportion, followed by DP, and the carbon effect of PP was negligible. (c) Based on the calculation of ISM model, 17 low-carbon measures were divided into three levels. The analysis results show that measures such as improving the quality of cultivated land and protecting the Ecological Redline would play a decisive role in the low-carbon development of LC. This study contributes to providing certain theoretical guidance and method reference for the realization of Low-Carbon LC project planning.

How to cite: Shan, W.: Study on the carbon effects of land consolidation and optimization path of low-carbon decision-making from the perspective of life cycle, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5812, https://doi.org/10.5194/egusphere-egu25-5812, 2025.

09:45–09:55
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EGU25-7040
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On-site presentation
Xudong Wu and Changxiu Cheng

High-resolution land use and land cover change (LULCC) products have become increasingly important in climate impact modelling. Simulating LULCC patterns on a fine scale enables us to uncover the intricate interconnections and heterogeneous characteristics inherent to terrestrial carbon and water cycles, as well as broader climate dynamics in the Anthropocene. Here, we present our recent advances in developing high-resolution LULCC datasets across multiple scales and their applications in various domains of climate impact modelling. By capturing the spatial heterogeneity of global and regional LULCC patterns, we illustrate how their spatiotemporal dynamics may evolve under diverse warming scenarios and the impacts of land-use changes on carbon sequestration, soil conservation, and land-atmosphere interactions. The outcomes highlight the critical role of spatially explicit LULCC datasets for advancing climate impact research and informing land-based adaptation strategies.

How to cite: Wu, X. and Cheng, C.: Developing high-resolution land use and land cover datasets to support climate impact modelling in the Anthropocene, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7040, https://doi.org/10.5194/egusphere-egu25-7040, 2025.

09:55–10:05
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EGU25-19650
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ECS
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On-site presentation
Souleymane Sy, Joel Arnault, Jan Bliefernicht, Benjamin Quesada, Verena Huber García, Gregory Duveiller, Abdel Nassirou Yahaya Seydou, Samuel Guug, Thomas Rummler, Patrick Laux, and Harlad Kunstmann

The forest landscape in West Africa faces significant challenges from rapid population growth, agricultural expansion, and urbanization. These anthropogenic land-use and land-cover changes (LULCC), including deforestation and afforestation, impact ecosystem-climate-carbon cycle interactions through biogeochemical emissions and greenhouse gas uptake. However, the capacity of the land-based carbon sink, encompassing LULCC emissions and CO2 uptake, remains uncertain. This study employs the fully coupled WRF-Hydro system, incorporating surface and subsurface hydrology and a dynamic carbon cycle, to perform high-resolution (3 km) convection-permitting simulations for the period 2011-2022. It assesses regional impacts of idealized LULCC scenarios by comparing several land use and afforestation simulations representing specific land cover transitions in the Sudan savannah belt of Burkina Faso and Ghana.

Model performance was validated using gross primary production (GPP) data from four eddy covariance sites along a land-use gradient (pristine savanna forest, cropland, and degraded grassland) in the Sudan savannah belt of Burkina Faso and Ghana and further evaluated by comparing simulated GPP and leaf area index (LAI) with Copernicus Land Monitoring satellite products. Overall, the model showed the best performance at the pristine savanna forest site with homogeneous vegetation.

Analysing of carbon cycle variables, including GPP, NPP, NEE, carbon residence time, and soil and vegetation carbon stocks, our results reveal that deforestation reduces GPP by 60% (-1.08 ± 0.1 gC/m²), carbon stocks by 45% (-1.79 ± 0.19 kgC/m²), and carbon residence time by 25% (-3.6 ± 0.9 years). Conversely, afforestation strategies, such as converting grassland to evergreen or mixed forest, can mitigate carbon losses by significantly increasing total carbon stocks (1.6 ± 0.19 kgC/m²) through increased canopy cover. Furthermore, our results indicate that converting grassland to evergreen forest can approximately double the carbon residence time in soils and ecosystems compared to afforestation options involving woody savanna or savanna. The study also investigates the underlying physical mechanisms behind LULCC-induced terrestrial carbon cycle responses.

How to cite: Sy, S., Arnault, J., Bliefernicht, J., Quesada, B., García, V. H., Duveiller, G., Seydou, A. N. Y., Guug, S., Rummler, T., Laux, P., and Kunstmann, H.: Afforestation as climate change mitigation strategy in West Africa: potential impacts on the terrestrial carbon cycle, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19650, https://doi.org/10.5194/egusphere-egu25-19650, 2025.

10:05–10:15
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EGU25-9521
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On-site presentation
Anem Dupre, Isabelle Gounand, Paul-Alain Raynal, and Caroline Pierre

Climate change and demographic growth are particularly acute in the Sahel, jeopardizing the sustainability of human land-uses. This call for research to provide relevant outputs to support policy-making in this area, especially in terms of land management and land degradation. In the Sahel, detailed observations of land use dynamics and drivers are scarce and existing global land-use models have difficulty representing it. One regional model has been developed by Stephenne and Lambin (2001) to fit the regional characteristics of Sahelian land use (SALU).

This communication explains how we adapted this model to the current state of the art to reconstruct past land-use dynamics in Senegal from 1961 to 2020. For that purpose, we warried out an extensive bibliographic search to obtain the most updated ranges for parameter values. We performed an in-depth analysis of the model's sensitivity to parameter uncertainties through delta-indices calculation. When applying the new model at national scale to Senegal, the so-obtained trends were consistent with available literature, exhibiting first agricultural expansion leading to deforestation, and then a switch to intensification in the mid-1990s, which affected both livestock forage consumption and fallow duration.

Finally, we apply the new model to a sub-region of Senegal: the Groundnut basin, that concentrates a large proportion of the national land-demand. This case-study showed the limits of the model when downscaling, as these demands were too high to be satisfied by the local production. This study thus opens perspectives for the refinement of landuse modelling in the Sahel, including for prospective scenarios addressing the future decades.

How to cite: Dupre, A., Gounand, I., Raynal, P.-A., and Pierre, C.: Modelling land-use dynamics in Western Sahel since 1960, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9521, https://doi.org/10.5194/egusphere-egu25-9521, 2025.

Coffee break
Chairpersons: Gregory Duveiller, Ryan Bright, Julia Pongratz
Observation driven studies
10:45–10:55
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EGU25-9004
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ECS
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On-site presentation
Yibiao Zou, Thomas Crowther, Gabriel Smith, Haozhi Ma, Lidong Mo, Lalasia Bialic-Murphy, Peter Potapov, Klementyna Gawecka, Chi Xu, Pablo Negret, Thomas Lauber, Zhaofei Wu, Dominic Rebindaine, and Constantin Zohner

Deforestation leads to habitat fragmentation, which adversely affects global biodiversity. Although some studies, using a separation-focused definition, have reported a decrease in fragmentation across 75% of the world's forests over recent decades, a comprehensive and ecologically relevant understanding of global fragmentation patterns remains lacking. In this study, we analyzed global fragmentation trends from 2000 to 2020, employing metrics that emphasize connectivity, aggregation, or separation. Connectivity-focused metrics reveal that 51% of global forests, particularly in tropical regions (58%), have undergone increased fragmentation—a rate nearly double that suggested by previous separation-focused metrics. This increase is corroborated by aggregation-focused metrics, which indicate heightened fragmentation in approximately 58% of forests worldwide and across all biomes. Further analysis attributes this escalation primarily to human activities, such as shifting agriculture and logging. Importantly, tropical protected areas have exhibited reductions in fragmentation by up to 82% compared to non-protected areas, underscoring the success of conservation efforts in these regions.

How to cite: Zou, Y., Crowther, T., Smith, G., Ma, H., Mo, L., Bialic-Murphy, L., Potapov, P., Gawecka, K., Xu, C., Negret, P., Lauber, T., Wu, Z., Rebindaine, D., and Zohner, C.: Forest fragmentation increased in over half of global forests during years 2000-2020, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9004, https://doi.org/10.5194/egusphere-egu25-9004, 2025.

10:55–11:05
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EGU25-3551
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ECS
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On-site presentation
Gayoung Yang, Thomas W. Crowther, Thomas Lauber, Constantin M. Zohner, and Gabriel Reuben Smith

Because of widespread forest fragmentation, 70% of the world’s forest area lies within 1 km of an edge. Forest biomass density near edges often differs markedly from biomass density in the interior. In some biomes, these “edge effects” are responsible for significant reductions in forest carbon storage. However, there is little consensus on the sign and magnitude of edge effects on forest biomass across the globe, which hampers their consideration in forest carbon stock accounting. Here, we examined eight million forested locations to quantify variability in edge effects at a global scale. We found negative edge effects across 97% of examined areas, with aboveground biomass density lower near edges than in interior forests. Higher temperature, precipitation, and proportion of agricultural land are linked to more negative edge effects. Along with differences in the spatial scale of analysis, this variation can explain contrasting observations among previous studies. We estimate that edge effects have reduced the total aboveground biomass of forests by 9%, equivalent to a loss of 58 Pg. These findings underscore the substantial impact of forest fragmentation on global biomass stocks and highlight the critical need to account for edge effects in carbon stock assessments.

How to cite: Yang, G., Crowther, T. W., Lauber, T., Zohner, C. M., and Smith, G. R.: A globally consistent negative effect of edge on aboveground forest biomass, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3551, https://doi.org/10.5194/egusphere-egu25-3551, 2025.

11:05–11:15
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EGU25-16539
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ECS
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On-site presentation
Di Xie, Luca Caporaso, Markus Reichstein, Deyu Zhong, and Gregory Duveiller

Vegetation plays a crucial role in regulating climate and sustaining the hydrological cycle. Preserving and expanding tree cover is potentially vital for mitigating climate change, as both the amount and spatial distribution of trees influence surface and atmospheric processes. While the direct effects of vegetation on surface properties are relatively well-studied, the indirect biophysical impacts of trees on cloud formation—particularly from trees outside forested areas—remain less explored, with the role of tree spatial patterns often overlooked. In this study, we used a space-for-time approach, high-resolution tree cover maps, and geostationary satellite data to investigate how tree cover, including its extent and spatial configuration, affects daytime and nighttime cloud formation across Africa. Our findings reveal distinct regional and temporal patterns: during the day, increased tree cover enhances cloud cover over tropical rainforests and arid steppes but reduces it over tropical savannahs. At night, a stronger negative relationship between tree cover and cloud formation emerges during the dry season, particularly in high-elevation areas of southern Africa. Mechanistically, these patterns are closely tied to sensible heat fluxes in water-abundant regions and to moisture availability in water-limited areas during the day, while nighttime cloud effects are linked to tree-induced variations in land surface temperature, likely through enhanced condensation on cooler surfaces. Incorporating tree cover heterogeneity alongside average tree cover offers further insights: in tropical savannahs, cloud formation is enhanced by 55.2% when heterogeneity is considered, compared to using tree cover alone, while in arid steppes, this increase is 12.4%. Conversely, in tropical rainforests, increased heterogeneity amplifies the negative impact of reduced tree cover on cloud formation. These findings underscore the importance of not only the extent but also the spatial arrangement of trees in afforestation and deforestation efforts. This data-driven analysis enhances the understanding of vegetation-cloud interactions, which remain uncertain and underrepresented in Earth system models, and provides valuable insights for planning and implementing future tree restoration projects in Africa.

How to cite: Xie, D., Caporaso, L., Reichstein, M., Zhong, D., and Duveiller, G.: How do trees impact cloud formation across Africa: the role of their spatial distribution, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16539, https://doi.org/10.5194/egusphere-egu25-16539, 2025.

11:15–11:25
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EGU25-84
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ECS
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On-site presentation
Obroma Agumagu

Land use and land cover change dynamics in the Niger Delta region from 1986 to 2024

Abstract

Understanding the effects of land use and land cover change (LULCC) is crucial for developing land management strategies that can reduce adverse effects on the hydrological cycle and the environment. This study examines the dynamics of LULCC in the Niger Delta of Nigeria, considering its implications for hydrological hazards. The study documents how the LULCC in the Niger Delta has changed from 1986 to 2024. A supervised maximum likelihood classification was applied to five land use classes (water bodies, rainforest, built-up, agriculture, and mangrove) derived from Landsat 5 TM and 8 OLI images from 1986, 2015, and 2024. The built-up and agriculture land classes record the greatest increase, about 8,229 and 6,727 sq. km (561.54% and 79.38%) respectively, while mangroves and rainforests showed the biggest decrease - 14,350 and 10,844 sq. km (-54.51 and -42.88%) respectively. Delta, Cross River, and Rivers States experienced the highest decrease in rainforest compared to other states, 64.0%, 49.49%, and 38.26% (5,711.0 sq km, 3,554.0 sq km and 1,297.0 sq km) respectively. The decreasing mangrove and rainforest cover impact on the hydrological functioning of the NDR resulting in flooding and increased risks and impacts associated with hydrological hazards. The study shows that multiple stakeholders, including the Nigerian government, need to manage LULCC and support forest and mangrove restoration and protection, particularly in Delta, Cross River, and Rivers States, to address rapid changes in the land use with impacts of hydrological functioning of the Niger Delta

 Obroma O Agumagu

 PhD
 Department of Environment and Geography
  University of York

 obroma4u@yahoo.com, oa824@york.ac.uk

 

How to cite: Agumagu, O.: Land use and land cover change dynamics in the Niger Delta region from 1986 to 2024 , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-84, https://doi.org/10.5194/egusphere-egu25-84, 2025.

11:25–11:35
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EGU25-2235
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ECS
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On-site presentation
Dimitris Koumoulidis, Ioannis Varvaris, Christos Theocharidis, Diofantos Hadjimitsis, and Charalampos Kontoes

Arable land and its quality are the principal sources of food supplies and fundamental determinants of food security. They underpin essential ecosystem services and food provisioning. The Food and Agriculture Organization (FAO)[1] identifies four critical dimensions—availability, access, utilization, and stability—that support food security. Ensuring the integrity of these dimensions is of the utmost importance.

Preserving agricultural productivity is crucial; nonetheless, adverse policies and practices, such as repurposing fertile land for urban expansion, overgrazing, deforestation, and ineffective irrigation methods, play a significant role in land quality and productivity degradation. Furthermore, when these issues are coupled with environmental and climatic modifications, they can impact numerous domains, including water management, public health, transportation, ecosystems, biodiversity, and human-induced hazards such as forest fires.

The EMMENA (East Mediterranean, Middle East and North Africa) spans diverse countries from Morocco to Yemen and Saudi Arabia, varying politically, economically, culturally, and environmentally. The region includes twenty-two countries covering approximately 12 million Km2. Multiple criteria guided the choice of this study area, given that the EMMENA region is characterized by marked social disparities. The region’s populations are vulnerable to climate and suffer the most from climate change effects, particularly as far as extreme heat occurrences and water scarcity combined with agriculture and ecosystem losses are concerned. Additionally, projections indicate that the population of the region’s expansive eastern part will surpass 1 billion by 2100. This demographic surge in areas with restricted agricultural land and limited water resources creates substantial socio-economic challenges and environmental effects. In the eastern area of the EMMENA region, limited and unevenly distributed water resources often create a dissonance between the demands of human communities and the necessity for environmental sustainability. Ultimately, according to FAO[2], the eastern segment of the region (Middle East) is witnessing frequent violent incidents across several countries. Jordan and Lebanon, which accommodate most refugees in the area, as well as the current instability in Syria, are experiencing substantial challenges in the stewardship of their natural resources, particularly land and water.

This study uses satellite imagery from the Landsat Thematic Mapper to investigate land-use alterations from 2000 to 2020 in Jordan, Syria, Lebanon, and Cyprus. The analysis incorporates the GlobeLand30 dataset, developed and sourced from the Global Land Discovery & Analysis[3] website provides global land cover data at a resolution of 30m to accurately depict the area’s land cover characteristics. ArcGIS maps from 2000, 2005, 2010, 2015, and 2020 were scrutinized to evaluate net land-use changes across ten classes, including grasslands, cultivated areas, forests, water bodies, and artificial surfaces.

The findings indicate a notable agricultural land abandonment in Syria, with a lesser degree observed in Lebanon. Every country has a discernible increase in the proliferation of built-up environments, particularly close to substantial residential areas. In Cyprus and Lebanon, forested regions characterized by tall vegetation have been devastated by wildfires, while in Jordan, minor land-use modifications are evident due to the desert landscape, the country's flat topography, and the arid climatic conditions.


[1] The State of Food and Agriculture 2006

[2] https://openknowledge.fao.org/server/api/core/bitstreams/766356ba-d028-4f06-b9b8-04d65bd8149c/content

[3] GLAD Global Land Analysis & Discovery

How to cite: Koumoulidis, D., Varvaris, I., Theocharidis, C., Hadjimitsis, D., and Kontoes, C.: Mapping Land Use Transformations in the Eastern part of the EMMENA Region in the last two decades. Addressing Food Security from a Land Use Perspective., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2235, https://doi.org/10.5194/egusphere-egu25-2235, 2025.

11:35–11:45
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EGU25-5568
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On-site presentation
Sinuo Xu and Yanxu Liu

Dryland ecosystems provide a wide range of ecological services essential to human well-being, but the poor soils of drylands make them highly vulnerable to damage from human activities, with far-reaching economic and social consequences. Therefore, the study of human-nature interactions in drylands is important for sustainable development. However, the economic and social impacts of different forms of human-nature interactions vary widely. Traditional land cover-based studies of indicators of human-nature interactions in drylands have failed to adequately distinguish between these impacts. Therefore, based on the Google Earth Engine cloud platform, this study extracted and mapped the distribution of WUIs in China's drylands for the period 1990 to 2020 by combining a variety of data, including GHL-S building area and land cover data. In addition, the study quantitatively analyses the relationships between spatial and temporal changes, landscape-scale changes, and regional GDP and population changes in the WUIs of China's drylands.

 

The results show that the WUI area in China's drylands has increased by about 15.9% over the past 30 years, and this expansion trend is particularly concentrated near large urban agglomerations.The WUI areas in the landscape are characterised by diversity, fragmentation, homogeneity and edge simplicity, which indicate a complex spatial pattern. To further explore the relationship between WUI expansion and regional GDP and population changes, this study used the Pearson correlation coefficient at the scale of 486 dryland counties. The results show a strong relationship between WUI expansion and economic and population growth, suggesting that human-nature interactions in China's drylands have been increasing over the past three decades and that the associated risks are growing.

 

In particular, the expansion of the WUI has significantly changed the socio-economic structure of these areas, leading to more frequent natural disasters and public health events that seriously threaten the survival and development of human communities. The study highlights that increasing human activities in drylands can exacerbate problems such as ecological degradation, land desertification and water scarcity, making it particularly urgent to implement scientific landscape planning and sustainable development strategies in these regions. Such planning not only helps to mitigate the negative impacts of human activities on the environment, but also strikes a balance between economic development and ecological conservation, and promotes the harmonious coexistence of society and nature.

 

This study provides important quantitative data and insightful analytical perspectives for understanding WUI changes in China's drylands and their impacts on economic and social development. In the future, as data technology and analytical methods continue to advance, similar studies will play an increasingly important role in the sustainable development of the world's drylands. An in-depth study of the interactions between human activities and the natural environment can help policy-makers address the challenges facing drylands and ensure that the ecological, economic and social systems in these areas can achieve long-term sustainable development.

How to cite: Xu, S. and Liu, Y.: Intensifying Human-Nature Interaction on China’s Dryland Landscape: An Evidence from Wildland–urban Interface, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5568, https://doi.org/10.5194/egusphere-egu25-5568, 2025.

11:45–11:55
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EGU25-5008
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ECS
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On-site presentation
Jyoti Sharma and Pankaj Kumar

Forestation significantly affects local temperatures, yet its effects on land surface temperature (LST) are complex and context-dependent. While much research has focused on the cooling effects of forestation globally by latitudes, less attention has been given to regional, seasonal and class-specific variations in LST.

This study examines how forestation changes daytime LST using a percentile-based approach and identifies climatic drivers of forest greenness through random forest regression across India's diverse forest types, including tropical, temperate, montane, alpine, and sub-alpine, which are further divided into 14 classes. It finds that forestation has both cooling and warming effects depending on forest class and percentiles, with cooling observed in 9 out of 14 forest classes, ranging from -4.1°C in mangroves to warming by 4.8°C in montane dry temperate forests. Forestation cools areas between 12–25°N but warms regions outside this range. Monthly temperature variations are substantial, with Class 13 warming during JJAS and MAM season and Class 5 cooling year-round. Greening variation is primarily driven by latent heat, which explains over 70% of the variation in Classes 4, 5, and 6, and by net photosynthesis, which accounts for up to 69.4% in Class 14. Other factors, such as precipitation, PDSI, and soil moisture, influence forest-specific LAI regulation.The study highlights the importance of spatial and temporal heterogeneity in assessing forestation’s effects on LST, providing valuable insights for climate adaptation and forest management, while suggesting future research to explore microclimatic feedbacks and long-term ecosystem impacts.

Keywords: Forestation, Land Surface Temperature, Climatic Drivers, Greenness,  Seasonal Variation

How to cite: Sharma, J. and Kumar, P.: Quantification of Potential Forestation induced change in Daytime Land Surface Temperature in India, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5008, https://doi.org/10.5194/egusphere-egu25-5008, 2025.

11:55–12:05
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EGU25-16629
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ECS
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Virtual presentation
Anoop pk and Resmi sr

Changes in land use and land cover (LULC) are closely linked to global warming and localized climate alterations, as urbanization significantly modifies surface and atmospheric conditions, resulting in a phenomenon known as the Urban Heat Island (UHI) effect. This study evaluates the intensity of the daytime Surface Urban Heat Island (SUHI) effect at a local scale using the landscape index (LI) proposed by Xu, which examines source and sink landscapes and their roles in SUHI intensity. The study evaluates SUHI intensity across different LULC types in districts of Kerala, India, using Land Surface Temperature (LST) data derived from Landsat 8 by single Channel algorithm technique and LULC classifications acquired from Esri Sentinel-2 for the period 2017–2023. Results reveal significant LST variations in 2019 and 2023, The districts Alappuzha, Ernakulam, Thrissur, and Thiruvananthapuram districts were more prone to SUHI Intensity.

How to cite: pk, A. and sr, R.: Land Use Land Cover Change and Surface Urban Heat Island Intensity: A Source-Sink Landscape Based Study in Kerala, India, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16629, https://doi.org/10.5194/egusphere-egu25-16629, 2025.

12:05–12:15
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EGU25-9338
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ECS
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Virtual presentation
Tirthankar (TC) Chakraborty and Yun Qian

Urbanization has traditionally been overlooked while estimating past changes in large-scale climate and is not resolved in future climate projections. This is due to the small fraction of Earth's surface historically covered by cities, the lack of representation of urban areas in most climate and Earth system models, and observational practices that try to minimize the influence of urban heat islands on the climate signal. In this study, we integrate global land surface temperature observations, which avoid many of the sampling pitfalls of ground-based weather station data, with historical urban area estimates to reveal that the urban contribution to continental- and regional-scale warming has become more significant over time, particularly in rapidly urbanizing regions and countries in Asia. Our findings suggest that anticipated urban expansion over the next century will further amplify the urban influence on large-scale surface climate, with projections indicating an approximate increase of 0.16 K for North America and Europe under a high-emission scenario by 2100. Consequently, we propose that urbanization, akin to other forms of land use/land cover change, must be explicitly included in climate change assessments. This inclusion necessitates the integration of dynamic urban extent and biophysical processes into current-generation Earth system models, enabling the quantification of potential urban feedback on the climate system across various scales.

How to cite: Chakraborty, T. (. and Qian, Y.: Urbanization amplifies continental- to regional-scale warming, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9338, https://doi.org/10.5194/egusphere-egu25-9338, 2025.

12:15–12:25
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EGU25-7853
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On-site presentation
Zhenzhong Zeng and Xiaoye Liu

A significant portion of terrestrial surface water is returned to the atmosphere through vegetation transpiration, making vegetation dynamics—such as deforestation, reforestation, and Earth’s greening—a critical driver of land evapotranspiration and vegetation-climate feedbacks. However, Earth system models (ESMs) exhibit substantial discrepancies in simulating the direction and magnitude of vegetation effects on evaporation. These inconsistencies stem from the heterogeneity of land-cover changes and limitations in ground-based observations, which complicate the quantification of these responses. In this study, we identify key disparities among ESMs in simulating evaporation and transpiration responses to vegetation changes, which lead to divergent predictions of climate feedbacks. A central issue is the persistent underestimation of the transpiration-to-evaporation ratio (Et/E), despite observational evidence indicating that transpiration dominates terrestrial evaporation fluxes. This underestimation is further compounded by inadequate representations of groundwater processes and limited soil depth in models, which restrict the availability of water for vegetation transpiration. To address these shortcomings, we propose the integration of enhanced observation-based constraints on model sensitivity, improved transpiration parameterizations, and the explicit inclusion of groundwater processes in ESMs. These advancements are essential for reducing uncertainties in vegetation-climate feedback projections and improving the accuracy of Earth system modeling.

How to cite: Zeng, Z. and Liu, X.: Modelled Sensitivity of Evapotranspiration to Vegetation Change: Reconciling Observations and Earth System Models, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7853, https://doi.org/10.5194/egusphere-egu25-7853, 2025.

12:25–12:30

Orals: Wed, 30 Apr | Room N1

The oral presentations are given in a hybrid format supported by a Zoom meeting featuring on-site and virtual presentations. The button to access the Zoom meeting appears just before the time block starts.
Chairpersons: Julia Pongratz, Gregory Duveiller, Ryan Bright
Model-driven studies of Biogeophysical effects
14:00–14:10
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EGU25-5786
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ECS
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On-site presentation
Yi Yao, Petra Sieber, Jonas Schwaab, Felix Jäger, and Sonia I. Seneviratne

Forests play a crucial role in European climate policy, owing to their potential for carbon sequestration, climate adaptation, biodiversity conservation, and other ecosystem services. Forest management directly changes land surface properties, e.g., albedo and roughness, and therefore has biogeophysical (BGP) impacts locally and potentially remotely due to advection and circulation. Previous studies investigating BGP climate impacts of forests focused on af/de-forestation, neglecting other types of forest management, like species change, tree health improvement, etc. To fill this gap, we employ the regional climate model COSMO-CLM, coupled with a land surface model with elaborate forest representation, CLM5, to perform simulations under multiple forest management scenarios. These scenarios vary in forest coverage, forest composition, and forest health (represented by leaf area index and canopy height), which allow us to detect the changes in climate induced by different forest management types and their combinations. The first results show that forest management-induced impacts have substantial spatial- and temporal- heterogeneity. Key findings include (i) both deforestation and broadleaf trees afforestation can decrease summer daily maximum temperature; (ii) broadleaf trees also increase winter daily minimum temperature in mid-latitude areas compared to needleleaf trees; (iii) afforestation increases precipitation in coastal regions of West Europe; and (iv) needleleaf trees afforestation decreases precipitation in the inland of Europe, but broadleaf trees afforestation increases it, etc. In our ongoing work, we will focus on understanding the mechanism behind these impacts by investigating changes in energy fluxes, water fluxes, wind speeds and other relevant variables.

How to cite: Yao, Y., Sieber, P., Schwaab, J., Jäger, F., and Seneviratne, S. I.: Regional climate modelling for a comprehensive understanding of forest management-induced biogeophysical climate impacts in Europe, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5786, https://doi.org/10.5194/egusphere-egu25-5786, 2025.

14:10–14:20
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EGU25-7051
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On-site presentation
Luca Caporaso, Matteo Piccardo, Georgios Blougouras, Gregory Duveiller, Caspar Roebroek, Mirco Migliavacca, and Alessandro Cescatti

Afforestation and deforestation have profound and diverse biophysical and biogeochemical impacts on the climate system, especially in Europe, a region characterized by different climatic and ecological zones. As tree planting is often considered a viable way to increase carbon removal from the atmosphere, understanding these impacts is crucial for achieving the goals of the European Green Deal. This study aims to quantify the climate consequences of forest cover changes, evaluating both local and broader non-local biophysical interactions.

We use advanced regional climate modeling with a 5 km spatial resolution, using the Regional Climate Model (RegCM5) coupled with the Community Land Model (CLM4.5). Simulations include a baseline scenario and two scenarios representing afforestation and deforestation, covering 2004–2014. 

Key variables such as surface energy fluxes, air temperature, and radiative balances are analyzed to reveal the local and spillover effects of land use change. The high-resolution modelling approach captures spatial heterogeneity and provides detailed insights into temperature dynamics and energy flux variations across European landscapes.

The results reveal a marked asymmetry in the biophysical effects of afforestation and deforestation, with deforestation exerting a stronger signal than afforestation. This asymmetry depends on the initial forest cover conditions, underscoring the need for fine-scale assessments. These results underline the importance of guiding land use planning and policy formulation to ensure the development of sustainable and effective climate change strategies. This work contributes to climate adaptation and mitigation efforts by providing actionable insights for integrating advanced modelling tools into land management practices.

How to cite: Caporaso, L., Piccardo, M., Blougouras, G., Duveiller, G., Roebroek, C., Migliavacca, M., and Cescatti, A.: Exploring Climate Implications of Land-Cover Change in Europe Through High-Resolution Climate Modeling  , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7051, https://doi.org/10.5194/egusphere-egu25-7051, 2025.

14:20–14:30
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EGU25-12983
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ECS
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On-site presentation
Georgios Blougouras, Luca Caporaso, Shijie Jiang, Markus Reichstein, Alessandro Cescatti, Alexander Brenning, and Mirco Migliavacca

Afforestation is widely considered as a key nature-based strategy for mitigating climate change, due to the carbon sequestration potential of forests. While much focus has been on the benefits of carbon sinks, afforestation also induces biophysical changes that can influence the energy budget and the water cycle. A key atmospheric variable potentially affected by these biophysical changes is vapour pressure deficit (VPD), which has a critical role in terrestrial ecosystem functioning, by affecting plant dynamics, growth and health. Through its role in vegetation dynamics, VPD strongly affects land-atmosphere interactions, water and carbon fluxes, and is critical to understanding how ecosystems respond to environmental changes. However, the atmospheric response of VPD to afforestation remains insufficiently explored, and depends on both temperature and absolute humidity. To this end, we performed high-resolution (5km) convection-permitting simulations over a European domain, coupling a regional climate model (RegCM5) with a land surface model (CLM4.5). We focus on the biophysical impacts of changing vegetation cover to VPD, by keeping the CO2 mixing ratio constant. We analyse the resulting VPD changes and explore how temperature and absolute humidity respond to vegetation changes, both at a local and non-local level. Counterintuitively, despite increases in the forest cover over Europe, the VPD experiences small but consistent increases. This suggests that the evapotranspiration changes from the increased forest cover cannot compensate for the higher temperature-induced capacity of the atmosphere to retain moisture, which is driven by changes in the energy budget. To assess possible negative VPD-induced influences of afforestation, we investigate the implications of the new VPD regimes for different plant functional types (PFTs) across European climate types. Our findings contribute to a more nuanced understanding of the biophysical impacts of afforestation and offer actionable insights for climate change mitigation strategies.  

How to cite: Blougouras, G., Caporaso, L., Jiang, S., Reichstein, M., Cescatti, A., Brenning, A., and Migliavacca, M.: Biophysical impacts of afforestation over Europe on atmospheric dryness – a simulation study, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12983, https://doi.org/10.5194/egusphere-egu25-12983, 2025.

14:30–14:40
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EGU25-16746
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ECS
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On-site presentation
Leonore Jungandreas, Ana Bastos, Jian Peng, and Sönke Zaehle

Cover cropping is increasingly recognized as a sustainable land management strategy with potential biophysical and biogeochemical climate implications. Although managed lands cover up to  70% of the Earth's ice-free land surface, their representation in Earth system models (ESMs) remains limited. This study integrates cover cropping into the global climate model ICON-MPIM to investigate its impacts on extreme weather events through biophysical effects on the atmosphere.

We analyze how the integration of idealized cover cropping alters surface properties, water and energy fluxes, and atmospheric processes, with a focus on extreme events such as droughts and heat waves. Preliminary results over Europe reveal a decrease in annual mean 2m air temperatures over eastern Europe but an increase over western Europe, with strong seasonal variations. Conversely, the maximum daily air temperature pattern shows the opposite trend, with increases over eastern Europe and decreases over western Europe. Moreover, remote changes, for example in 2m air temperature or maximum daily air temperature, also occur in regions where no cover crops are grown, such as in the tropics and polar regions or the ocean. These findings suggest that the climate response to cover cropping is highly heterogeneous, emphasizing the importance of considering both spatial and temporal dynamics.

This approach represents a first step toward exploring the theoretical potential of cover cropping to influence climate dynamics and extreme events while recognizing the limitations of the model's representation of agricultural management practices. By addressing land management in a generalized yet systematic manner, this study contributes to an improved understanding of the influence of land management on land-atmosphere interactions and provides a basis for future research on the role of managed lands in climate systems.

How to cite: Jungandreas, L., Bastos, A., Peng, J., and Zaehle, S.: Exploring Land Management Impacts on Extreme Weather Events: Cover Cropping in ICON-MPIM, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16746, https://doi.org/10.5194/egusphere-egu25-16746, 2025.

14:40–14:50
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EGU25-16490
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ECS
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On-site presentation
Dashan Wang, Shijing Liang, and Zhenzhong Zeng

Afforestation and reforestation are widely recognized as effective strategies for mitigating anthropogenic climate change. However, satellite-based assessments of their carbon sequestration potential remain uncertain, particularly when accounting for the dynamic nature of climate conditions, vegetation-climate feedbacks, fire-related disturbances, and the trade-offs posed by surface albedo changes. Using a coupled Earth system model, we estimate that optimal global forestation could sequester 31.3-69.2 Pg C between 2021 and 2100 under a sustainable shared socioeconomic pathway. Regionally, the greatest mitigation potential is found in tropical areas, while mid- to high-latitude regions exhibit higher heterogeneity, emphasizing the need for tailored strategies and further refinement of nature-based mitigation plans. Our findings highlight the critical role of considering disturbances, such as fires, and minimizing adverse albedo effects in the estimation of carbon mitigation potential from targeted forestation. We also advocate for the development of high-resolution, consistent maps identifying suitable forestation areas, with a focus on avoiding environmentally sensitive lands and minimizing conflicts with other human activities.

How to cite: Wang, D., Liang, S., and Zeng, Z.: Climate Mitigation Potential of Targeted Forestation Considering Climate Change, Fires, and Albedo Effects, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16490, https://doi.org/10.5194/egusphere-egu25-16490, 2025.

14:50–15:00
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EGU25-4057
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ECS
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On-site presentation
Felix Jäger, Jonas Schwaab, Mona Bukenberger, Steven J. de Hertog, and Sonia I. Seneviratne

While large-scale afforestation and reforestation are heavily discussed as strategies for nature-based climate change mitigation and adaptation, massive deforestation is ongoing. Such widespread land use and land cover changes (LULCCs) not only alter the global climate through biomass carbon uptake or release but also through biogeophysical (BGP) processes related to changes in surface roughness, evaporation, transpiration, and albedo. These BGP effects act as local forcing to land-atmosphere interactions and lead to in situ climate responses. Caused by advection and spatio-temporal land-atmosphere-ocean interaction, they also generate nonlocal climate responses that occur remotely from the LULCC.

The non-local partition of climate response signals, and how it occurs at spatial scales different from the forcing, is still the subject of ongoing research. Here, we present a spectral perspective on climate responses to surface forcing from LULCC that aids in achieving a systematic and mechanistic understanding of the arousal and robustness of large-scale BGP effects.

We introduce spectral decomposition of forcing and response fields into a sum of signals with different wavelengths based on spherical harmonics to compare the two fields across spatial scales. Building on this approach, we define the ’cross-scale’ response signal based on the difference of response and forcing spectra. With our novel tool SCISSOR, a Spectral ClImate Signal SeparatOR, we determine the cross-scale signal of BGP-driven temperature response to deforestation, which strongly resembles the nonlocal signal as estimated by established methods such as moving window regression and checkerboard interpolation.

We further show that SCISSOR and other spectral tools can be used to analyze consistent and divergent characteristics of climate responses to LULCC between Earth System Models. We discuss the assumptions, advantages and limitations of both SCISSOR and the established signal separation methods and assess their potential use for future analysis of the complex interaction between climate and land surface changes.

How to cite: Jäger, F., Schwaab, J., Bukenberger, M., de Hertog, S. J., and Seneviratne, S. I.: SCISSOR: a Spectral ClImate Signal SeparatOR to assess complex climate responses to land cover changes, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4057, https://doi.org/10.5194/egusphere-egu25-4057, 2025.

15:00–15:10
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EGU25-12325
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On-site presentation
Tiexi Chen and Xin Chen

Land management is a critical component of human activities; however, due to the lack of data and methodological limitations, its influence on vegetation change has been challenging to identify and quantify. Existing models are insufficient in effectively describing these processes, while observation-based comparative analyses often rely on grid-walking methods, which fail to provide a clear depiction of land management processes at the regional scale. The Paired Land Use Experiment (PLUE) theory draws inspiration from the paired watershed approach by selecting regions with significant differences in land management but consistent climate change to create a land management control experiment. This theory has undergone validation in multiple regions. This report introduces the application of the PLUE method in various case studies, highlighting the significant impact of land management on vegetation change. Moving forward, these land management processes are suggested to be integrated as submodules within models to enable broader and more systematic research.

How to cite: Chen, T. and Chen, X.: Advancements in the Paired Land Use Experiment Method for Land Management Research, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-12325, https://doi.org/10.5194/egusphere-egu25-12325, 2025.

15:10–15:20
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EGU25-14933
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ECS
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On-site presentation
Marzieh Mortezapour, Kirsten Zickfeld, and Vivek Arora

Reforestation is a key nature-based solution for mitigating climate change. However, changes in land cover through reforestation can significantly influence the climate and hydrological cycle, affecting water availability and other critical components of the Earth system. Understanding these impacts is essential for developing effective climate adaptation strategies and ensuring sustainable land management in the coming decades.

This study leverages simulations with the Canadian Earth System Model (CanESM5.1), a state-of-the-art Earth system model, to quantify hydrological responses to two large-scale reforestation scenarios. The first scenario reverses historical deforestation, restoring tree cover to pre-industrial levels by the year 2070, while the second implements a sustainable reforestation strategy by the same year. To isolate the effects of reforestation, a reference simulation with land-cover fixed at the year 2015 configuration is also conducted. The study employs a two-stage simulation framework—historical (1850–2015) and future (2015–2200)—with multiple ensemble members, using SSP1-2.6 forcing to align with the Paris Agreement’s climate goals.

Preliminary results reveal that large-scale reforestation induces statistically significant climate and hydrological responses at both regional and global scales. These findings highlight the potential for unintended consequences of land-based climate mitigation strategies, emphasizing the need for holistic assessments to guide future land management and policy decisions.

How to cite: Mortezapour, M., Zickfeld, K., and Arora, V.: Hydrologic Cycle Impacts of Large-Scale Reforestation at Global and Regional Scales, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14933, https://doi.org/10.5194/egusphere-egu25-14933, 2025.

15:20–15:30
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EGU25-6588
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ECS
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On-site presentation
Olivier Asselin, Martin Leduc, Dominique Paquin, Nathalie de Noblet-Ducoudré, Diana Rechid, and Ralf Ludwig

In order to meet a stringent carbon budget, shared socioeconomic pathways (SSPs) aligned with the Paris Agreement typically require substantial land-use changes (LUC), such as large-scale forestation and bioenergy crop plantations. What if such a low-emission, intense-LUC scenario actually materialized? In this contribution, we quantify the biophysical effects of LUC under SSP1-2.6 using an ensemble of regional climate simulations over Europe. We find that LUC projected over the 21st century, primarily broadleaf-tree forestation at the expense of grasslands, reduce summertime heat extremes significantly over large swaths of continental Europe. In fact, cooling from LUC trumps warming by greenhouse gas (GHG) emissions, resulting in milder heat extremes by 2100 for about half of the European population. Forestation brings heat relief by shifting the partition of turbulent energy fluxes away from sensible and towards latent heat fluxes. Impacts on the water cycle are then assessed. Forestation enhances precipitation recycling over continental Europe, but not enough to match the boost of evapotranspiration (green water flux). Run-off (blue water flux) is reduced as a consequence. Some regions experience severe drying in response. In other words, forestation turns blue water green, bringing heat relief but compromising water availability in some already-dry regions.

How to cite: Asselin, O., Leduc, M., Paquin, D., de Noblet-Ducoudré, N., Rechid, D., and Ludwig, R.: Blue in green: forestation turns blue water green, mitigating heat at the expense of water availability, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6588, https://doi.org/10.5194/egusphere-egu25-6588, 2025.

15:30–15:40
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EGU25-14168
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ECS
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On-site presentation
Pierre Etienne Banville, Alexander MacIsaac, and Kirsten Zickfeld

Large-scale forestation, including reforestation, afforestation, and forest restoration, is prevalent in net zero climate strategies due to the carbon sequestration potential of forests. In addition to capturing carbon, forestation has biogeophysical effects, such as changes in albedo, that can influence surface temperatures locally (local effects), and at distant locations (non-local effects). Biogeophysical effects may offset the cooling benefits of carbon sequestration, hence requiring a robust understanding of their mechanisms to adequately integrate forestation into climate mitigation strategies and carbon accounting frameworks. Yet, the role of ocean dynamics, such as ocean circulation, ocean-atmosphere interactions, and ocean-sea ice interactions in driving non-local effects remains underexplored. In this study, we investigate the impact of ocean dynamics on the magnitude and geographic patterns of the non-local biogeophysical effects of large-scale forestation over a multicentury timescale using the University of Victoria Earth System Climate Model (UVic ESCM), an Earth System Model of Intermediate Complexity (EMIC). We conduct multicentury paired global forestation simulations, with the first simulation using a dynamic ocean (Dynamic Ocean Simulation) and the second using prescribed sea surface temperatures (Prescribed SST Simulation). To be able to separate local from non-local effects, we use the checkerboard approach in both simulations, alternating grid cells undergoing forestation (subject to local and non-local effects) with grid cells remaining deforested (subject to non-local effects only), and compare land surface temperature to a control simulation where all grid cells remain deforested. Using the model simulation data, we perform a surface energy balance decomposition for each simulation at multiple points in time. After a 500-year period, we find a non-local warming effect on land surface temperature in both the Dynamic Ocean Simulation and the Prescribed SST Simulation. However, these non-local warming effects are of much greater magnitude and encompass a greater geographic area, particularly at high latitudes, in the Dynamic Ocean Simulation compared to the Prescribed SST Simulation. Moreover, in the Dynamic Ocean Simulation, non-local warming effects on land continue to strengthen for multiple centuries after most of the forest has regrown and local effects have stabilized. This prolonged land surface warming is the result of a gradual increase in sea surface temperature over multiple centuries caused by ocean-atmosphere interactions combined with the ocean’s thermal inertia. Furthermore, the ocean warming is amplified by climate feedback mechanisms, including the water vapor feedback, fueled by ocean evaporation, and the sea ice-albedo feedback. Consequently, forestation has non-local warming effects that develop gradually and intensify over multiple centuries due to interactions within the Earth system. Net zero policies and carbon accounting frameworks must therefore consider the complete Earth system response over a sufficiently long timeframe to include the slow ocean’s response. Without the consideration of the full Earth system response, net zero policies relying heavily on forestation may not deliver on their climate objectives.

How to cite: Banville, P. E., MacIsaac, A., and Zickfeld, K.: Ocean dynamics amplify non-local warming effects of forestation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14168, https://doi.org/10.5194/egusphere-egu25-14168, 2025.

15:40–15:45
Coffee break
Chairpersons: Ryan Bright, Julia Pongratz, Gregory Duveiller
Impacts of LULCC
16:15–16:25
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EGU25-4384
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ECS
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Highlight
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On-site presentation
Konstantin Gregor, Christopher P.O. Reyer, Thomas A. Nagel, Annikki Mäkelä, Andreas Krause, Thomas Knoke, and Anja Rammig

Land use, land management, and land cover change (LULCC) play a pivotal role in shaping ecosystems, influencing global and local climate, biodiversity, and the provision of resources.
Therefore, effective land use strategies need to consider the trade-offs between these often competing objectives. 

Legislative frameworks, including the EU Biodiversity Strategy, EU Forest Strategy, and national policies, aim to protect natural landscapes, enhance ecosystem services, and leverage resources for climate mitigation and the bioeconomy. However, reconciling these objectives poses a critical challenge for policymakers, land managers, and conservation stakeholders.

Using process-based ecosystem modeling and robust multi-criteria optimization, we analyzed how portfolios of forest management strategies could sustain multiple ecosystem services across diverse climate scenarios. The study incorporated strict constraints, such as protecting 10% of Europe’s land area and maintaining stable harvest levels under all climate scenarios. Results revealed significant trade-offs: limited flexibility due to the constraints led to low-diversity portfolios that compromised multi-functionality and increased regional risks. Moreover, productive northern regions would need to prioritize timber provision to compensate for declining harvests elsewhere, conflicting with targets for increasing forest carbon sinks in those regions. The uneven distribution of protected areas also introduced disparities in conservation efforts.

Our findings underscore the need for coordinated European land use strategies that address these conflicts. Complementary measures to the EU strategies are essential to achieve goals for carbon sequestration, resource availability, and ecosystem services under a changing climate. While the analysis focused on forests, the approach can be adapted to other land use types.

How to cite: Gregor, K., Reyer, C. P. O., Nagel, T. A., Mäkelä, A., Krause, A., Knoke, T., and Rammig, A.: Developing land use strategies in Europe under climate change and legislative constraints, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4384, https://doi.org/10.5194/egusphere-egu25-4384, 2025.

16:25–16:35
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EGU25-10035
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ECS
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On-site presentation
Thomas Gérard, Sietze Norder, Judith Verstegen, Jonathan Doelman, Stefan Dekker, and Floor Van der Hilst

Land-use change is a major driver of biodiversity loss and a key contributor to greenhouse gas emissions, making it crucial to mitigate climate change and preserve biodiversity. This is especially relevant for Brazil, where agricultural expansion impacts biodiversity- and carbon-rich biomes. Achieving Brazil's commitments to the Paris Agreement and the Convention on Biological Diversity requires balancing agroeconomic development with biodiversity preservation and climate change mitigation. However, more comprehensive information is needed on land-use trade-offs and synergies across varying global change contexts. To address this gap, we quantified trade-offs and synergies among these objectives through 2050 under three land-use change scenarios in Brazil. We assessed the impact of each scenario by estimating spatial changes in carbon stock, mammal distributions, and agricultural revenue. Our results confirm that agricultural growth in Brazil occurs at the expense of biodiversity preservation and climate change mitigation, and vice versa. The primary drivers of these trade-offs and synergies are changes in natural vegetation cover and agricultural land, led by global demand for agricultural products. Under a SSP3-7.0 scenario, rising demand for agricultural products from 2015 to 2050 is projected to expand agriculture into natural areas. This pathway increases Brazil's agricultural revenue by $39.7 billion USD annually but reduces land carbon stock by 4.5 Gt and shrinks mammal distribution areas by 3.4%. Conversely, the SSP1-1.9 scenario projects declining agricultural demand over the same period, driving the reconversion of agricultural land to natural vegetation. This shift increases carbon stock by 5.6 Gt and expands mammal distribution areas by 6.8%, though it would lower agricultural revenue by $19.7 billion USD annually. Our findings further highlight that containing agriculture outside biodiversity- and carbon-rich areas, along with strategic ecosystem restoration, presents opportunities to harmonize agroeconomic development with biodiversity preservation and climate change mitigation.

How to cite: Gérard, T., Norder, S., Verstegen, J., Doelman, J., Dekker, S., and Van der Hilst, F.: Trade-Offs and Synergies between Climate Change, Biodiversity, and Agricultural Economy Across Various Future Land Use Scenarios in Brazil., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10035, https://doi.org/10.5194/egusphere-egu25-10035, 2025.

16:35–16:45
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EGU25-4654
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ECS
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On-site presentation
Xiaotian Ma and Hancheng Dai

In the future, agricultural land use is expected to continue expanding to meet the increasing food demand driven by population and economic growth. However, policy actions aimed at addressing climate change and biodiversity loss may impose constraints this expansion, leading to a triple land-use conflict. By linking land conservation priority data with the global economic land-use model (GLOBIOM), this study assesses the climate mitigation potential, biodiversity benefits, and food security risks under land-based climate mitigation and biodiversity conservation measures. The results indicate that dual measures could contribute to a cumulative carbon reduction of 242 Gt between 2020 and 2050, while maintaining global biodiversity integrity at 2020 levels by 2050. However, this would require a reduction in agricultural land use before mid-century, leading to a 57% increase in global food prices by 2050 compared to the baseline scenario and an additional 368 million people at risk of undernurishment, compared to 257 million under only climate mitigation measures. This is primarily due to the significant amplification effect of BECCS on food security under the land protection expansion scenario. Extensive scenario simulations based on Monte Carlo sampling reveal a nearly linear relationship between the carbon reduction potential of land-based measures and the resulting additional undernurishment risks, while the marginal biodiversity benefits decrease, further highlighting the "impossible trinity" of climate mitigation, biodiversity conservation, and food security arising from land-use conflicts. Although this study suggests that global food aids or agricultural subsidies could address the side effect at a cost of around 0.39% of GDP, the actual potential for food assistance remains limited.

How to cite: Ma, X. and Dai, H.: Joint action for climate mitigation and biodiversity conservation may undermine global food security, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4654, https://doi.org/10.5194/egusphere-egu25-4654, 2025.

16:45–16:55
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EGU25-6052
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ECS
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On-site presentation
Hazel Mooney, Stephen Arnold, Ben Silver, Piers Forster, and Cat Scott

Woodlands sequester carbon dioxide from the atmosphere, which could help mitigate climate change. As part of an effort to reach net-zero greenhouse gas emissions by the year 2050, the UK’s Climate Change Committee (CCC) recommend increasing woodland cover from a UK average of 13% to 17-19%. Woodlands also have the potential to affect air quality, in part due to the emission of biogenic volatile organic compounds (BVOCs) which are precursors to major atmospheric pollutants, ozone (O3) and particulate matter (PM). This study presents for the first-time estimates of BVOC emissions that are consistent with net-zero aligned afforestation in the UK. The BVOC emission scenarios consider suitability of tree species for the UK coupled with regionally appropriate emissions potentials. We quantify the potential emission of BVOCs from five afforestation experiments using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) (v2.1) in the Community Land Model (CLM) (v4.5) for the year 2050. Experiments were designed to explore the impact of the variation in BVOC emissions potentials between and within plant functional types (PFTs) on estimates of BVOC emissions from UK land cover, to understand the scale of change associated with afforestation to 19% woodland cover by the year 2050.  

Our estimate of current annual UK BVOC emissions is 40 kt yr-1 of isoprene and 46 kt yr-1 of total monoterpenes. Broadleaf afforestation results in a change in UK isoprene emission of between -4% and +131%, and a change in total monoterpene emission of between +6% and +52%. Needleleaf afforestation leads to a change in UK isoprene emission of between -3% and +20%, and a change in total monoterpene emission of between +66% and +95%.   

Our study highlights the potential for net-zero aligned afforestation to have substantial impacts on UK BVOC emissions, and therefore air quality, but also demonstrates routes to minimising these impacts through consideration of the emissions potentials of tree species planted. We show that incorporating regionally appropriate emissions factors, information about present day abundance of tree species, and the likely role of different species in the UK’s future forests, can substantially alter estimates of emissions. This study highlights an important interaction between the land and the atmosphere, for climate change mitigation options, specifically afforestation, to hold the potential to impact air quality. 

How to cite: Mooney, H., Arnold, S., Silver, B., Forster, P., and Scott, C.: Future Forests: estimating biogenic emissions from net-zero aligned afforestation pathways in the UK, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6052, https://doi.org/10.5194/egusphere-egu25-6052, 2025.

16:55–17:05
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EGU25-17991
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On-site presentation
Jiangong Bi, Yoonji Kim, Yoon Jung Kim, and Junga Lee

Urban forests play a critical role in addressing various urban environmental challenges, such as mitigating climate change, enhancing biodiversity, and improving habitat connectivity. To optimize the spatial allocation and management of urban forests, it is essential to consider both environmental impacts (e.g., carbon emissions and resource consumption) and ecosystem services (e.g., carbon storage and habitat quality)(Chaplin-Kramer et al., 2017). In this context, this study employs Life Cycle Assessment (LCA) to evaluate the environmental costs associated with urban forest establishment and maintenance, and the InVEST model to assess the localized impacts on ecosystem services through spatially detailed analysis. By integrating these methodologies, a comprehensive evaluation of urban forest development strategies is conducted.

To address the environmental challenges associated with rapid urban development in Sejong City, this study evaluates two urban forest development scenarios: centralized (large-scale, contiguous forests) and decentralized (multiple, small-scale forests). Sejong City, designated in 2007 and officially launched in 2012 as Korea’s administrative capital, has undergone extensive urbanization over the past decade, resulting in significant habitat loss, degradation of ecological quality, and increased ecosystem fragmentation (Sejong City, 2024). These trends highlight the critical need for mitigation strategies, with urban forest development emerging as a promising solution.

This study employs openLCA software to quantify environmental costs, including carbon emissions, energy consumption, and resource usage, incurred during the establishment and maintenance of urban forests. Furthermore, the InVEST Carbon Storage and Sequestration model and Habitat Quality model are utilized to simulate spatially explicit changes in carbon storage and habitat quality under the two scenarios. By integrating these results, the study provides a comprehensive assessment of the environmental and ecological performance of each scenario, offering valuable insights for the formulation of sustainable land-use strategies in urban forest planning.

The analysis revealed that decentralized urban forest development, characterized by the establishment of small forests across multiple locations, effectively mitigates habitat fragmentation, provides suitable habitats for diverse species, and enhances biodiversity by strengthening ecological connectivity and increasing species richness in urban environments. In contrast, centralized urban forest development incurs higher initial environmental costs but provides greater long-term carbon storage and habitat stability through large contiguous forests.

This study demonstrates that the integration of LCA and spatial modeling provides a robust framework for comprehensively evaluating the environmental and ecological impacts of urban forest development strategies. By quantitatively assessing the trade-offs between environmental costs and ecological benefits, this research identifies the importance of balanced land-use strategies that consider both centralized and decentralized approaches.

 

*This work was supported by the Core Research Institute Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education(NRF-2021R1A6A1A10045235).

How to cite: Bi, J., Kim, Y., Kim, Y. J., and Lee, J.: A Comprehensive Assessment of Urban Forest Scenarios Using LCA and InVEST Models, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17991, https://doi.org/10.5194/egusphere-egu25-17991, 2025.

17:05–17:15
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EGU25-17112
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ECS
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On-site presentation
Ching-Wen Chou and Shyue-Cherng Liaw

Suburban areas undergoing rapid urbanization face significant challenges in balancing ecological and socioeconomic sustainability. Land-use changes play a crucial role in shaping the dynamics of regional ecosystem service values. This study focuses on the Lanyang River Basin in Taiwan, adjacent to the Greater Taipei Metropolitan Area, to assess the impact of land-use changes on ecosystem service values and explore strategies for sustainable development. Using Nationwide Land Use Investigation Data from 1995, 2007, and 2020, we projected land-use dynamics for 2045 under a regular growth scenario and optimized land-use allocation through linear programming. The Integrated Valuation of Ecosystem Services and Tradeoffs (InVEST) model and Geographic Information System (GIS) were employed to quantify spatial and temporal value changes in carbon storage, habitat quality, and annual water yield. Results reveal a significant decline in the value of carbon storage and habitat quality under the regular growth scenario, driven by the expansion of built-up areas. In contrast, the optimization scenario enhances these ecosystem service values by increasing grassland coverage, although trade-offs emerge, particularly with a reduced annual water yield. Notably, the impact on annual water yield is significantly constrained by regional precipitation patterns, as the Lanyang River Basin is a subtropical humid region. Our insights highlight the importance of tailored sustainable regional planning that considers land-use types, geographic characteristics, and factors such as vegetation diversity in grasslands to optimize spatial resource use. This study provides an innovative framework for integrating ecosystem service values with scenario simulation to inform sustainable land-use planning. The findings offer actionable insights for suburban sustainability in rapidly urbanizing regions. Future research should incorporate socioeconomic realities and policies to refine simulation model accuracy and enhance decision-making, supporting a balanced approach to ecological conservation and regional development.

How to cite: Chou, C.-W. and Liaw, S.-C.: Scenario Simulation of Ecosystem Service Values for Suburban Sustainability: A Case Study of the Lanyang River Basin, Taiwan, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17112, https://doi.org/10.5194/egusphere-egu25-17112, 2025.

17:15–17:25
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EGU25-6375
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ECS
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On-site presentation
Muhannad Hammad, Kim Cohen, Gilles Erkens, and Esther Stouthamer

Land subsidence is a wicked problem that presents significant challenges to both urban and rural areas in the Netherlands. With annual subsidence rates reaching up to 10 mm in urban areas and over 30 mm in rural polder areas, the increasing damage caused by subsidence represents a long-term economic burden at both regional and national levels. Additionally, the land subsidence process contributes to greenhouse gas (GHG) emissions, further exacerbating environmental challenges. Addressing the persistent losses and emissions associated with land subsidence is a complex task that requires a holistic approach.

This study explores the role of integrated water and land management in mitigating land subsidence and the associated impacts on both society and the Earth system, using our backcasting approach developed within the Living on Soft Soils research programme [nwa-loss.nl]. This approach begins by formulating alternate long-term objectives for 2050, focusing on minimizing subsidence rates, reducing subsidence-related GHG emissions, and mitigating associated economic damage. These objectives were explicitly defined for both rural and urban contexts, with input from scientists and stakeholders. The three alternate objectives reflect varying levels of ambition and feasibility, with continued unaltered management practises, representing the business-as-usual scenario, serving as a baseline for comparison. Next, preparing the backcasting approach requires to define and select the water and land management measure sets that simulation modelling may select to alter land subsidence and the associated impacts from business as usual. Between rural and urban areas, the water management strategies of reducing the groundwater level lowering are fairly similar, but for the land management strategies there are strong context differences. In some rural areas, to reach the long-term objective one may opt for drastic land use changes, e.g. changing established agriculture into paludiculture, or reallocating land to forests or wetlands (in tandem with raising groundwater tables, serving GHG reduction and ecosystem restoration goals), while maintaining established agricultural use in other rural areas with higher groundwater levels and less drastic water management measures or less reducing the groundwater level lowering. In urban areas, land management strategies focus on soil stabilization, blue-green infrastructure, and district-level interventions to mitigate subsidence while enhancing urban resilience to climate change.

The modelling steps in this study explore the solution space and develops land subsidence management scenarios towards the three sustainable long-term objectives. Model runs using the water and land management strategies either individually or in different combinations. The performance of scenarios is evaluated based on their ability to reduce subsidence and the associated socioeconomic cost terms. With the performance analysed, the outcomes are lined up to introduce sustainable pathways for implementing measure sets, allowing stakeholders and decision-makers to make informed decisions and choose the most feasible and sustainable options, ensuring that these interventions are tailored to the local context and conditions, and also that these interventions contribute to broader Earth system sustainability.

In conclusion, this study highlights the role of integrating water and land management strategies in addressing land subsidence via a framework provides scenarios and pathways toward achieving sustainable land subsidence management in the Netherlands.

How to cite: Hammad, M., Cohen, K., Erkens, G., and Stouthamer, E.: Water and land management scenarios for addressing land subsidence in the Netherlands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6375, https://doi.org/10.5194/egusphere-egu25-6375, 2025.

17:25–17:35
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EGU25-11262
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ECS
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On-site presentation
Simon P. Heselschwerdt and Peter Greve

Ongoing anthropogenic climate change and other human interventions increasingly interfere with freshwater availability and its distribution. Land use, land management, and land cover change (LULCC), in particular, shapes water resources by altering the partitioning of precipitation into green and blue water. Yet, a comprehensive understanding of how LULCC influences global precipitation partitioning is lacking. We address this gap by employing the Blue-Green Water Share (BGWS) metric, which quantifies water partitioning dynamics using monthly precipitation data, while monthly runoff and transpiration data serve as proxies for blue and green water flows. Using simulations from the Land Use Model Intercomparison Project (LUMIP), a component of the Coupled Model Intercomparison Project Phase 6 (CMIP6), we evaluate how LULCC impacts precipitation partitioning. Historical land use change impacts are isolated using simulations without land use change (hist-noLu). Additionally, we assess the effects of different land use scenarios on the BGWS under the Shared Socioeconomic Pathways (SSPs) 1-2.6 and 3-7.0 (ssp370ssp126Lu and ssp126ssp370Lu). Regression analysis and variable importance computations are performed to identify key drivers of BGWS trends, comparing the relative contributions of LULCC and climatic factors to shifts in green and blue water flows. Our results highlight the critical need to understand green and blue water dynamics for sustainable water resource management in the face of changing climatic and land use conditions. By advancing our knowledge of the hydrological consequences of LULCC, this research provides actionable insights to inform land-based climate mitigation and adaptation strategies.

How to cite: Heselschwerdt, S. P. and Greve, P.: Impacts of land use and land cover change on blue and green water resources availability, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11262, https://doi.org/10.5194/egusphere-egu25-11262, 2025.

17:35–17:45
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EGU25-1640
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ECS
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On-site presentation
Yifeng Hou, Yaning Chen, Yupeng Li, Fan Sun, and Xueqi Zhang

Land is important in the productive life of human societies, as the ecological environment has been shown to be closely related to societal advancement. Currently, the dynamics of land use and cover change (LUCC) have emerged as a focal point in global change studies, playing a key role in urbanization development, regional climate, agricultural production, and ecological sustainability. Driven by the global context of increasing population, the human-land conflict is deepening issues around resource utilization and environmental problems. Soil and water matching in a land basin is important for securing land demand, alleviating human-land conflicts, and promoting sustainable development in the region. The Tarim River Basin (TRB) is the largest inland river basin in China and primarily sustains an agricultural economy centered around oases. 

Over the past half-century, global warming and carbon emissions have become a serious threat to the sustainable development of society. It is therefore critically important to find viable solutions to the structural layout of land use that will promote current and future ecological security in the southern Xinjiang region. The aim in conducting the present study is to explore options for safeguarding the demand for land in the TRB and to promote the synergistic development of regional socio-economic and ecological environments. Using remote sensing data, the study will employ the PLUS model to simulate the evolution of spatial and temporal land-use patterns in the basin under different future scenarios while also considering the ecological value of land-use types. The connection between land development and the ecological environment is examined through the lens of relative ecological value and ecological impact. This study provides a strong scientific foundation for future land management and ecological sustainable development in the TRB.

How to cite: Hou, Y., Chen, Y., Li, Y., Sun, F., and Zhang, X.: Land Structure Change and Ecological Effects Under Future Development Scenarios in Tarim River Basin, Central Asia, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1640, https://doi.org/10.5194/egusphere-egu25-1640, 2025.

17:45–17:55
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EGU25-823
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ECS
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On-site presentation
Peichao Gao, Changqing Song, Sijing Ye, Yifan Gao, Jiaying Lv, Yuanhui Wang, Haoyu Wang, and Fang Li

Global warming is a critical global challenge, and at the 26th Conference of the Parties to the UNFCCC in 2021, nations committed to limiting the global temperature rise to within 1.5°C by 2100. As a signatory, China has introduced ambitious climate targets, including carbon peaking and neutrality goals, which will significantly influence its land system changes. This study, focusing on China, integrates data from the Global Change Assessment Model (GCAM) with an enhanced CLUMondo model to simulate land system changes under two scenarios: a 1.5°C warming scenario and a reference scenario without updated emissions measures. The results show high simulation accuracy and highlight that, under the 1.5°C scenario, ecosystems improve, with shrubland, wetland, and forest areas projected to grow significantly, especially in southern and coastal regions. However, cropland is expected to decrease, with up to 35% converted to wetlands and forests by 2100, particularly in key grain-producing regions, raising food security concerns. These findings underscore the profound impacts of 1.5°C climate pledges on China’s land systems, offering crucial insights for climate risk mitigation and sustainable development.

How to cite: Gao, P., Song, C., Ye, S., Gao, Y., Lv, J., Wang, Y., Wang, H., and Li, F.: Long-term Impacts of 1.5 °C Global Climate Pledges on China's Land Systems, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-823, https://doi.org/10.5194/egusphere-egu25-823, 2025.

17:55–18:00

Posters on site: Tue, 29 Apr, 10:45–12:30 | Hall X1

The posters scheduled for on-site presentation are only visible in the poster hall in Vienna. If authors uploaded their presentation files, these files are linked from the abstracts below.
Display time: Tue, 29 Apr, 08:30–12:30
Chairpersons: Gregory Duveiller, Ryan Bright, Julia Pongratz
X1.37
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EGU25-18014
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ECS
Adele Zaini, Sara M. Blichner, Jing Tang, Rosie A. Fisher, Marianne T. Lund, and Terje K. Berntsen

As global surface temperatures continue to rise, vegetation is expected to adapt, with high-latitude forests projected to migrate northward into the Arctic regions. This shift will result in significant changes in land cover, influencing the climate through various biogeophysical and biogeochemical feedback mechanisms. While many studies have shown that changes in albedo drive substantial warming, a more comprehensive evaluation of the impacts associated with changes in Biogenic Volatile Organic Compound (BVOC) emissions is needed. Some studies suggest that BVOC-related effects could significantly influence climate in these pristine regions, potentially counteracting the albedo effect. BVOCs play a crucial role in atmospheric chemistry and aerosol formation; changes in their emissions can alter aerosol properties, subsequently affecting cloud characteristics and potentially leading to a cooling effect. In this study, we use the Norwegian Earth System Model v2 (NorESM2) with projected vegetation migration, running nested experiments under current climatic conditions and warmer climate forcing scenarios to assess the radiative forcing of BVOC-related impacts, in comparison with the albedo change. Preliminary findings suggest that under current climate conditions, BVOC-related impacts are insufficient to rival the warming effect of albedo changes; however, their relative role could be significantly amplified in warmer future climates.

How to cite: Zaini, A., Blichner, S. M., Tang, J., Fisher, R. A., Lund, M. T., and Berntsen, T. K.: Arctic expansion of boreal forests: can the BVOC emission impact rival the albedo effect?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18014, https://doi.org/10.5194/egusphere-egu25-18014, 2025.

X1.38
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EGU25-1393
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ECS
Tyler Houston and Marcus Breil

Afforestation in the mid-latitudes exhibits uncertain climate benefits due to dominating biogeophysical effects. While forestation is an important carbon sink, the balance of increased albedo and evapotranspiration remains the primary factor dictating the net climate benefit of afforestation in the region. We aim to formulate optimal strategies for afforestation in Europe and discover if a positive climate benefit can be achieved. We are performing idealised afforestation simulations with ICON-ESM while incorporating species-specific information into the included JSBACH land-surface model. This has been gathered through a tree species data inventory, resulting in the parameterisation of the following variables for eight European tree species: Vegetation Height, Maximum LAI, Maximum Surface Roughness, Maximum Woody Carbon, and Albedo (VIS/NIR). By incorporating this information into existing JSBACH PFTs, we create new species-specific PFTs with which to simulate the effects of monospecific afforestation. This idealised afforestation will be carried out for each species across Europe. The local climate effects will then be compared on a cell-by-cell basis to determine the most beneficial species for afforestation in each region. This focus on the comparison of inter-species differences will elicit the trees species locally best-suited for climate mitigation, allowing optimized afforestation strategies to be developed. Results from these experiments will be presented and initial conclusions drawn regarding such strategies.

How to cite: Houston, T. and Breil, M.: Exploring the Climate Mitigation Potential of Afforestation in Europe using Species-Specific Modelling, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1393, https://doi.org/10.5194/egusphere-egu25-1393, 2025.

X1.39
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EGU25-6225
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ECS
Belen Benitez, Carole Dalin, and Bertrand Guenet

Food systems are responsible for one-third of global greenhouse gas (GHG) emissions, and these emissions are predominantly driven by land-based and land-use change (LUC) emissions linked to agricultural production (Crippa, M. et al., 2021). Incorporating all sources of GHG emissions, including those from land-use change, is essential for fully assessing the sustainability of agricultural production and enabling informed decision-making. However, many studies either overlook LUC-related emissions, do not account for diverse land-use change scenarios, neglect to accurately differentiate the agricultural commodities driving the change, or focus on aggregated subnational scales (Halpern, B.S. et al., 2024; Singh, C., & Persson, 2022; Lam, W. Y. et al., 2021). Our research addresses these gaps by providing high-resolution (5 arc-minute), global-scale estimates of LUC emissions attributed to crop and livestock production from 2000 to 2020. We quantify LUC emissions and attribute them to specific crops and pasture established on newly converted lands, providing crop- and grass-specific carbon emission intensities, which represent the carbon emissions generated per ton of production. Additionally, our study integrates emissions resulting from new pasture areas into livestock GHG emission intensity data from previous research, providing a more detailed livestock emission assessment. This approach offers a comprehensive evaluation of the carbon footprint of crop and livestock production and reveals the spatial and temporal dynamics of LUC-related emissions, thus providing valuable insights into the environmental impact of agricultural expansion.

How to cite: Benitez, B., Dalin, C., and Guenet, B.: Attributing gridded land use change carbon emissions to crop and grass production from 2000 to 2020., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6225, https://doi.org/10.5194/egusphere-egu25-6225, 2025.

X1.40
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EGU25-7768
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ECS
Yuxuan Wang and Siqiong Luo

Vegetation greening on the Qinghai-Tibet Plateau (QTP) plays a crucial role in altering the energy balance and frozen ground conditions. As vegetation cover increases, albedo decreases, leading to surface warming. This study used high-resolution land-use datasets from different time periods to parameterize plant functional types (PFTs) on the QTP and conducted sensitivity simulations with the RegCM5.0-CLM4.5 model. By comparing land cover changes (LCC) across different years, the study evaluated the effects of vegetation greening on energy balance and frozen ground dynamics. The results show that LCC caused significant warming, with land surface temperature (LST) increasing by 0.10°C in 2000 and 0.36°C in 2020.  Soil temperature (ST) changes were observed as deep as 280 cm, with the largest variations between 2 cm and 100 cm depths, leading to increases of 0.07°C (in 2000) and 0.31°C (in 2020).  This warming intensified frozen ground thawing, expanding thawing regions and shrinking freezing areas.  Variations in LST and energy flux components were regionally dependent, influenced by meteorological factors and circulation patterns.  The findings underscore that vegetation greening, by reducing albedo, reshapes energy fluxes, increasing air temperature, LST, and ST, while accelerating thawing and reducing freezing in frozen ground regions.

How to cite: Wang, Y. and Luo, S.: Modeling the effects of vegetation greening on frozen ground over the Qinghai-Tibet Plateau, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7768, https://doi.org/10.5194/egusphere-egu25-7768, 2025.

X1.41
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EGU25-3441
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ECS
Xiaoxin Zhang, Bin Chen, Jiafu An, and Chen Lin

Mining is a major driver of deforestation. However, quantitatively estimating its full impact on natural forests and the associated carbon emissions is challenging due to incomplete global data on mining activities. Here, we compiled a comprehensive inventory of global mining activities, including 236,028 mining areas with an overall accuracy of 87.37% to analyze deforestation within mining areas and the associated forest carbon emissions from 2001 to 2023. Our results reveal that deforestation directly caused by mining activities is two to three times higher than previously estimated from widely used mining datasets, accounting for 19,765 km2 of deforestation and 0.75 Pg CO2 of carbon emission in the 21st century. Notably, 50.29% of this deforestation is linked to undocumented mining activities. This study highlights the significant deforestation directly caused by mining activities on a global scale, and particularly underscoring the environmental impact of informal mining.

How to cite: Zhang, X., Chen, B., An, J., and Lin, C.: Overlooked deforestation from global mining activities in the 21st century, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3441, https://doi.org/10.5194/egusphere-egu25-3441, 2025.

X1.42
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EGU25-7746
Kim-Anh Nguyen and Yuei An Liou


Golf courses have increasingly contributed to the economic growth of Vietnamese cities like Hanoi. However, their environmental impacts, particularly regarding land use and resource management, remain a concern. This study utilizes Sentinel-2 and Landsat satellite imagery, combined with Geographic Information Systems (GIS), to monitor golf courses in Hanoi’s metropolitan area. By evaluating two detection methods—Normalized Difference Vegetation Index (NDVI) analysis and feature recognition—we identify the strengths and limitations of these approaches in urban settings. While NDVI is constrained by similar vegetation signatures in tropical climates, feature recognition captures distinct golf course characteristics. The findings contribute to sustainable urban land use planning and highlight the potential of advanced remote sensing technologies in environmental conservation.

How to cite: Nguyen, K.-A. and Liou, Y. A.: Monitoring Hanoi's Golf Courses Using Remote Sensing and Machine Learning for Sustainable Land Use Planning, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7746, https://doi.org/10.5194/egusphere-egu25-7746, 2025.

X1.43
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EGU25-2580
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ECS
Nora L. S. Fahrenbach, Steven J. De Hertog, and Robert C. Jnglin Wills

While afforestation and avoided deforestation are important strategies for climate change adaptation and mitigation, their effects on atmospheric circulation and hydroclimate remain underexplored. Here, we use future afforestation simulations in an SSP1-2.6 and SSP3-7.0 world from seven CMIP6 models from the Land Use Model Intercomparison Project (LUMIP). Our results reveal robust increases in precipitation and evapotranspiration, coupled with widespread decreases in net moisture flux (i.e., decreases in precipitation minus evaporation) in the tropics, particularly over Africa. The moisture flux changes are driven by opposing effects of afforestation on upper and lower-tropospheric circulation: The increase in surface roughness significantly slows down the moisture-laden surface winds from the ocean, reducing moisture transport and suppressing topographically-induced precipitation. However, the concurrent increase in near-surface moist static energy strengthens convection and thus the upper-tropospheric circulation. These findings underscore the significant role of surface roughness changes and land-atmosphere interactions in shaping tropical hydroclimate, and highlight the need for careful consideration of the hydroclimate impacts of land-based climate strategies.

How to cite: Fahrenbach, N. L. S., De Hertog, S. J., and Jnglin Wills, R. C.: The rough reality: How forests reshape tropical circulation and hydroclimate, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2580, https://doi.org/10.5194/egusphere-egu25-2580, 2025.

X1.44
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EGU25-10306
Yuxiang Zhang

Forest gain in the tropics is always assumed to cool land surface as much as the warming induced by forest loss. However, the observations from multiple satellites show that the impacts of forest gain on local land surface temperature are robustly weaker than forest loss. This asymmetry comes from the contrasting changes of vegetation properties, which are verified by vegetation indices. Forest loss which is primarily caused by intense disturbances such as fire and deforestation, could result in the rapid change of biophysical processes, while forest gain is mainly related to vegetation regrowth, whose changes are not often that rapid. These asymmetric effects of forest gain and loss are not well represented in current Earth system models because of the fixed biophysical parameters used, thus could lead to the overestimation of the climatic mitigation of forestation in the future, especially in a short period. This highlights the necessity to improve the representation of forest demographic on biophysical vegetation properties for better projecting the climate benefits of future forestation.

How to cite: Zhang, Y.: Asymmetric impacts of tropical forest gain and loss on temperature due to forest growth revealed by satellite observation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10306, https://doi.org/10.5194/egusphere-egu25-10306, 2025.

X1.45
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EGU25-9934
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ECS
M. B. Nicodemus Ujih, Rosazlin Abdullah, Akira Watanabe, Faustina Sangok, Nur Azima Busman, and Lulie Melling

Southeast Asia hosts the largest areas of tropical peatland in the world, with Malaysia’s contribution being significant, covering approximately 2.7 million hectares. Many of these areas have been converted to oil palm plantations and face distinctive challenges due to the high acidity of peat soil, about pH 3.3 – 3.5. Liming is implemented to decrease soil acidity and enhance soil fertility. However, the impact of liming on soil CO2 emissions and oil palm physiology in tropical peatlands remains underexplored. This study investigates the effects of liming on soil CO2 emissions and oil palm physiological variables such as assimilation rate (A), stomatal conductance (Gsw), intercellular CO2 concentration (Ci), transpiration (E), and intrinsic water use efficiency (iWUE) on tropical peat soils. The experiment was arranged in a randomized complete block design with four liming treatments: 0 (T1), 2 (T2), 4 (T3), and 8 (T4) t ha⁻¹. Soil pH increased significantly with an increase in lime application. The soil CO2 emission was significantly higher in T4 (203 g C m-2 yr-1), followed by T3 (184 g C m-2 yr-1), T2 (140 g C m-2 yr-1) and T1 (111 g C m-2 yr-1). Similarly, assimilation rate (A)exhibited significant differences across treatments, with T4 recorded the highest rate (15.1 µmol m-² s-¹), and the lowest is T1 (10.8 µmol m-² s-¹). Conversely, Gsw was higher in the T1 (0.32 mol m-² s-¹) than T4 (0.24 mol m-² s-¹). Soil CO2emissions positively correlated (p < 0.01) with soil pH, A, Ci, and chlorophyll content. In contrast, a significant negative correlation (p < 0.01) was observed with Gsw, and E. These findings highlight that liming improves soil acidity, and oil palm physiological variables but also accelerates soil carbon loss as CO2 emissions.

How to cite: Ujih, M. B. N., Abdullah, R., Watanabe, A., Sangok, F., Busman, N. A., and Melling, L.:  Impact of Liming on Soil CO2 Emissions and Oil Palm Physiology in Tropical Peatlands, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-9934, https://doi.org/10.5194/egusphere-egu25-9934, 2025.

X1.46
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EGU25-10669
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ECS
Yanwen Zhang and Shuangcheng Li

Forests have substantial potential to mitigate climate change through carbon sequestration and to deliver important co-benefits to society. Long-term datasets on anthropogenic forest disturbances are vital for understanding their impacts on terrestrial carbon budgets, hydrothermal balance, and climate regulation. However, there is currently no quantitative information regarding the patterns and trends of anthropogenic forest disturbances in China.

In this study, we developed a comprehensive forest disturbance dataset for China by integrating Landsat imagery with the LandTrend algorithm, thus capturing spatiotemporal changes in forest disturbances from 1986 to 2020. We then used socioeconomic and environmental satellite data and direct sources such as statistical yearbooks to identify anthropogenic forest disturbance information, applied LightGBM model to reconstruct their spatial patterns and evaluate key driving factors. Our results indicate that approximately 37% of China’s forests experienced disturbances over the past three decades. Following the implementation of national forest protection measures, increased timber imports, and logging quota management after 1990, anthropogenic forest disturbances declined markedly. Between 1990 and 2000, anthropogenic activities led to a forest loss of 4.601 × 104 km2, including a notable increase in forest loss in the Pearl River Delta region as a result of urbanization. In terms of the other drivers of forest loss, more than 80% of forest losses were linked to forestry-related activities, with additional contributions from commodity-driven deforestation and shifting agriculture.

The high-resolution, systematically developed anthropogenic forest disturbance dataset presented in this study offers critical baseline data for forest ecology research particularly in the context of China. It further supports national strategies aimed at addressing climate change, enhancing the monitoring of human-induced forest disturbances, and safeguarding forest carbon sinks.

How to cite: Zhang, Y. and Li, S.: Mapping the Spatial Distribution of Anthropogenic Forest Disturbances in China from 1986 to 2020, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10669, https://doi.org/10.5194/egusphere-egu25-10669, 2025.

X1.47
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EGU25-14059
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ECS
Koramanghat Unnikrishnan Jayakrishnan, Alexander MacIsaac, and Kirsten Zickfeld

Reforestation is a widely considered nature-based method for climate mitigation. The net effect of reforestation on the climate system has two components: i) biogeochemical and ii) biogeophysical effects. The biogeochemical effect of reforestation involves the radiative cooling from the reduction in atmospheric CO2 concentration due to additional carbon storage on land. The biogeophysical effects are due to the changes in energy and moisture balances at the surface associated with reforestation. For example, the changes in land surface albedo due to reforestation modifies the surface energy balance, and consequently, affects the climate response. We hypothesize that both the biogeochemical and biogeophysical effects of reforestation are scenario dependent. The scenario dependence of biogeochemical effects could arise from different amount of additional carbon storage on land in different scenarios (larger CO2 fertilization in higher emission scenarios could lead to larger storage of carbon on land), while differences in the climate feedbacks such as the snow albedo feedback could result in scenario dependence of biogeophysical effects. In this study, we investigate the scenario dependence of biogeochemical and biogeophysical effects of reforestation by performing three sets of simulations with an Earth system model of intermediate complexity. The first set are baseline scenarios in which fossil fuel emissions, non-CO2 greenhouse gas forcing and aerosol forcing prescribed from different SSP scenarios with land use change fixed at 2020 values. The second and third sets involve emission and concentration driven reforestation experiments (each implemented with different SSP scenarios) designed for separating the biogeochemical and biogeophysical effects of reforestation.  

We find that biogeochemical effects show strong scenario dependence (Figure 1). Further, biogeochemical effects do not increase monotonically, despite the increase in additional carbon storage on land with the increase in background emissions. The non-monotonic behavior of the biogeochemical cooling effects is because of the logarithmic dependence of radiative forcing on atmospheric CO2 concentration and the saturation of the land carbon sink at higher emission levels. Biogeophysical effects are also non-monotonic in response to the increase in background emissions, however, they exhibit less scenario dependence than biogeochemical effects (Figure 1). Our results show that the effectiveness of reforestation for climate mitigation declines under high emission scenarios. Therefore, immediate cessation of fossil fuel emissions not only stabilizes the climate but also enhances the climate mitigation potential through reforestation.

Figure 1. The a) net, b) biogeochemical and c) biogeophysical effects of reforestation in five different SSP Scenarios.

How to cite: Jayakrishnan, K. U., MacIsaac, A., and Zickfeld, K.: Scenario Dependence of Biogeochemical and Biogeophysical Effects of Reforestation , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14059, https://doi.org/10.5194/egusphere-egu25-14059, 2025.

X1.48
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EGU25-16199
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ECS
Tianyu Wang

Urbanization worldwide has resulted in a substantial increase in abandoned rural settlements, presenting a unique opportunity to enhance food security and mitigate climate change. Here we quantify the potential of these underutilized lands for optimized agricultural production and carbon sequestration, using China as a compelling case study. Leveraging high-resolution Night-Time Light (NTL) data from LuoJia1-01, we identify approximately 5.66 Mha of abandoned settlements across rural China, representing 38.05% of all rural settlements. We employ a probabilistic multi-objective spatial optimization of land use (pMOLU) model to strategically allocate these lands between reclamation for agriculture and afforestation, maximizing both food production and carbon sequestration under various scenarios. The results reveal that reclaiming abandoned settlements could yield an additional 9–21 Mt of food annually, while reforestation efforts could sequester 5–14 Mt of carbon per year. Furthermore, we propose a spatial prioritization strategy for the phased implementation of consolidation across the country and evaluate its beneficial impacts on food security and climate goals.The findings underscore the untapped potential of abandoned rural settlements for promoting sustainable development and offer a robust framework for optimizing land-use decisions in China and beyond.

How to cite: Wang, T.:  Unleashing the Potential of Abandoned Rural Settlements for Optimized Food and Climate Goals, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16199, https://doi.org/10.5194/egusphere-egu25-16199, 2025.

X1.49
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EGU25-16459
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ECS
Laura Thölix, Tommi Bergman, Risto Makkonen, Kalle Nordling, Antti-Ilari Partanen, and Joonas Merikanto

Boreal forests are particularly important for carbon storage. A warmer climate, combined with the expansion of these forests, is expected to enhance their role as carbon sinks in the future. Deforestation, where forests are replaced by crops and pastures, strongly affects land surface albedo and transpiration, leading to substantial carbon emissions into the atmosphere—a key driver of climate change.

In this study, we investigate the impacts of boreal forests on future climate using EC-Earth with full carbon cycle and prescribed CO2 concentration. EC-Earth-Veg captures the physical effect mechanisms, while EC-Earth-CC incorporates both physical and biogeochemical effect. The biogeochemical effect can be isolated and quantified from these results.

Globally, the temperature responses to deforestation due to physical and biogeochemical effects largely cancel each other, but locally, deforestation has a large (more than 1°C in annual mean) impact on annual temperatures over deforested regions, accompanied with a marked expansion of Arctic sea ice.

How to cite: Thölix, L., Bergman, T., Makkonen, R., Nordling, K., Partanen, A.-I., and Merikanto, J.: Evaluating physical and biogeochemical climate effects of boreal forests with EC-Earth, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16459, https://doi.org/10.5194/egusphere-egu25-16459, 2025.

X1.50
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EGU25-20336
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ECS
Gunnar Thorsen Liahjell

Centuries of mountain farming and forestry have caused the treeline in Norway to be situated up to hundreds of meters below its climatic potential. With climate change further raising this potential, vast areas of mountainous Norway are becoming open to tree growth. This shift in land cover significantly alters the hydrological balance, as trees typically have higher evapotranspiration rates than the vegetation they replace. Given that Norway’s power mix is largely dominated by hydropower, these changes in hydrology pose a potential threat to energy production.

To quantify the impact of this shift, we employ a high-resolution coupled atmosphere-land model (WRF-CTSM) using current and projected vegetation maps from the Natural History Museum in Oslo.

As the evapotranspiration (ET) levels in Norway are currently not well-constrained targeted fieldwork with mobile eddy covariance towers is being conducted to measure turbulent fluxes in representative areas. This data will be used to update the model's plant functional types to better represent the local vegetation.

The updated model will then be run under different SSP scenarios to provide more robust estimates of current and future ET levels in Norway and their potential impact on hydropower production.

How to cite: Thorsen Liahjell, G.: On the Impact of Tree-Line Expansion: A Threat to Hydropower Resources?, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20336, https://doi.org/10.5194/egusphere-egu25-20336, 2025.

X1.51
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EGU25-11170
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ECS
Nur Azima Busman, Muhammad Zarul Shazreen, Faustina E. Sangok, Akira Watanabe, and Lulie Melling

The conversion of tropical peat swamp forests to oil palm plantations has significant implications for soil CO2 emissions. However, the extent of these changes remains highly uncertain, particularly across different stages of land-use conversion at a single site. Therefore, in this study, we present continuous measurements of soil CO2 flux, environmental conditions, and soil chemical properties from a peat swamp forest in Malaysia undergoing conversion to an oil palm plantation. The study, conducted from January 2011 to April 2022, encompasses three distinct phases: peat swamp forest (Jan 2011–Feb 2017), land preparation involving drainage, land clearing, and mechanical compaction (Mar 2017–Apr 2018), and oil palm plantation (May 2018–Apr 2022). Soil CO2 flux was measured on a monthly basis using the manual chamber method, and variations in environmental and soil chemical properties were also measured. Drainage during land preparation lowered the groundwater level (GWL) from −6.4 cm before conversion to −83.5 cm. The GWL further dropped to −112.8 cm in the first year of planting, then gradually increased from the second to the fourth year, reaching −65.7 cm. Air and soil temperatures also increased following conversion, peaking during the second year before starting to decrease in the third year of planting, possibly due to the growing of oil palm canopy. Soil total carbon and nitrogen contents remained unchanged throughout the study period, while the degree of humification and ash content increased after planting. Soil CO2 fluxes before conversion ranged from 30 to 403 mg C m−2 h−1, with no significant changes observed during land preparation (136–397 mg C m−2 h−1). However, soil CO2 fluxes increased during the first to the third year of oil palm planting (140–619 mg C m−2 h−1), followed by a decrease in the fourth year (140–368 mg C m−2 h−1). This decline may suggest that most of the labile carbon may have been lost during the first three years after planting. However, as this trend was observed only over one year, continued monitoring should be done. Soil CO2 flux showed a negative correlation with GWL before the conversion, but no such correlation was observed after conversion. This is likely due to the smaller variation in GWL following conversion, which is maintained by plantation management practices. Overall, our long-term measurements provide valuable insights into the temporal dynamics of soil CO2 flux during the conversion of tropical peat swamp forests to oil palm plantations, allowing for a more robust evaluation of the impacts of conversion.

How to cite: Busman, N. A., Shazreen, M. Z., Sangok, F. E., Watanabe, A., and Melling, L.: Evaluating soil CO2 fluxes during the transition from peat swamp forest to an oil palm plantation, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11170, https://doi.org/10.5194/egusphere-egu25-11170, 2025.