ITS4.4/ERE1.10
Nature-Based Solutions and Climate Engineering in Climate Governance

ITS4.4/ERE1.10

EDI
Nature-Based Solutions and Climate Engineering in Climate Governance
Co-organized by CL3.2/SSS12
Convener: Haozhi Pan | Co-conveners: Claudia WienersECSECS, Herman Russchenberg, Henk A. Dijkstra, Karen Sudmeier-Rieux, Zahra Kalantari, Stephan Barthel, Carla S. S. Ferreira
Presentations
| Tue, 24 May, 15:10–18:18 (CEST)
 
Room N1

Presentations: Tue, 24 May | Room N1

Chairpersons: Zahra Kalantari, Karen Sudmeier-Rieux, Carla S. S. Ferreira
15:10–15:16
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EGU22-5175
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ECS
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Virtual presentation
Jessica Page, Haozhi Pan, and Zahra Kalantari

Urban areas are major contributors to global greenhouse gas (GHG) emissions. To address climate change, many cities have developed climate action plans (CAPs) as strategic roadmaps to reduce their emissions and strive for emission neutrality and climate resilience by 2050 or before. It has been more than a decade since the first of these plans were put in place, and it is now important to evaluate these plans and to access whether city-level climate ambitions will be realised or perhaps need adjustment to pursue for improvements in climate resilience over time

 This work aims to further our understanding of urban GHG emissions, by completing existing urban carbon emissions data with blue-green contributions to the urban carbon cycle. In a previous study, it was found that the inclusion of blue-green emissions in urban carbon accounting in Stockholm, Sweden had a significant impact on that region’s ability to reach net zero emissions in the coming decades (Page et al., 2021). In this study, we complete the urban emissions data for cities across the European Union (EU) in order to assess if, and for which types of cities, the inclusion of blue-green emissions in the GHG accounting is similarly relevant.

Furthermore, we will use data about the CAPs produced and implemented by these cities together with the completed GHG emissions in order to assess whether the actions and plans made by many European cities have actually had any impact on the emissions from these cities. The inclusion of blue-green emissions and sequestrations in this assessment is particularly important, as many of the strategies included in CAPs impact blue-green areas, such as the implementation of nature-based solutions (NBS).

Conclusions will be drawn about the role of green-blue areas in urban GHG emissions, the role which CAPs have played in reducing emissions in European cities, and how and where these could potentially be adapted to further reduce future GHG emissions in urban areas.

Keywords: Sustainable cities; Greenhouse Gas Emissions; Nature-based Solutions; Climate Action Plans

References:

Page J, Kåresdotter E, Destouni G, et al. (2021) A more complete accounting of greenhouse gas emissions and sequestration in urban landscapes. Anthropocene 34: 100296. DOI: 10.1016/j.ancene.2021.100296.

How to cite: Page, J., Pan, H., and Kalantari, Z.: Completing Urban GHG Emissions Data to Assess the Effectiveness of Climate Action Plans in Europe, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-5175, https://doi.org/10.5194/egusphere-egu22-5175, 2022.

15:16–15:22
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EGU22-8613
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ECS
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Presentation form not yet defined
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Haozhi Pan, Jessica Page, Cong Cong, and Zahra Kalantari

Clear implementing plan for Nature-based solutions (NBS) beyond conceptualization is critical for successful in mitigating urban carbon emissions. In this paper, we demonstrate an approach to deploy nature-based solutions on high-resolution (25x25-meter) land use grid and its carbon emission reduction benefits for 50 major European Union (EU) cities. The deployment process takes 3 parts: 1) downgrading carbon emission data with larger spatial scales (10x10km GID data) to high-resolution cells using land use and socioeconomic data; 2) identifying opportunities and suitability of deploying NBS on these land use cells from a database with meta-analysis on the emission reduction potentials of different types of NBS; 3) Estimating total carbon emission potentials from spatial deployment and coupling of of multiple NBS with parametric simulation. Our results indicate that vast areas of urbanized and un-urbanized lands in EU cities can apply NBS to further mitigate carbon emissions. The reduction potential is huge and can contribute to a critical wedge of carbon neutrality.     

How to cite: Pan, H., Page, J., Cong, C., and Kalantari, Z.: Spatial deployment of Nature-based Solutions to support carbon neutrality for 50 EU cities., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8613, https://doi.org/10.5194/egusphere-egu22-8613, 2022.

15:22–15:28
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EGU22-7868
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ECS
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Virtual presentation
Esko Karvinen, Leena Järvi, Toni Viskari, Minttu Havu, Olivia Kuuri-Riutta, Pinja Rauhamäki, Jesse Soininen, and Liisa Kulmala

Urban areas are notable sources of atmospheric CO2 and cities are currently setting up climate programs with the aim of carbon neutrality in the near future. For example, two major cities in Southern Finland, Helsinki and Turku, have set their targets for 2035 and 2029, respectively. Carbon neutrality can be achieved by reducing carbon emissions, compensating them, and / or strengthening carbon sinks in urban vegetation and soils, the last of which is often deemed the most cost-efficient option. However, the current understanding of biogenic carbon cycling in urban environments is based on dynamics observed in more well-known ecosystems such as forests and agricultural lands. Urban ecosystems differ from non-urban areas in terms of temperature, precipitation and water cycling, pollution, and the level of human-induced disturbance. Thus, there is a need for observations on urban carbon to accurately model and estimate the carbon sinks and stocks in urban green space.

We aimed to monitor urban biogenic carbon cycle with an extensive field campaign carried out around the SMEAR III ICOS station in 2020–2022, accompanied by a few satellite sites around the capital region of Finland. In this presentation, we will show soil carbon pools and the dynamics of soil respiration at five different types of urban green space: a managed park lawn with and without trees, small urban forest, apple orchard, and street tree site. Soil respiration was measured with both regularly repeated manual chamber measurements and automatic chambers throughout two growing seasons. Soil carbon stock was estimated by soil samplings conducted in 2020 and 2021. We investigate the role of different drivers in soil CO2 emission at the various urban green space types and compare those to corresponding metrics measured in non-urban areas. In addition, we test the applicability of Yasso model to simulate the soil carbon dynamics in urban areas.

How to cite: Karvinen, E., Järvi, L., Viskari, T., Havu, M., Kuuri-Riutta, O., Rauhamäki, P., Soininen, J., and Kulmala, L.: The potential of urban soils for carbon neutral cities, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7868, https://doi.org/10.5194/egusphere-egu22-7868, 2022.

15:28–15:34
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EGU22-10433
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On-site presentation
Carsten Paul, Axel Don, Bartosz Bartkowski, Martin Wiesmeier, Sebastian Weigl, Steffi Mayer, Markus Steffens, André Wolf, Cenk Dönmez, and Katharina Helming

There is growing awareness of the role that agricultural soils can play for climate change mitigation. Agricultural management that increases soil organic carbon (SOC) stocks constitutes a nature-based solution for carbon dioxide removal. As soils store about twice the amount of carbon found in the atmosphere, even small relative increases could significantly reduce global warming.

However, increasing SOC requires management changes that come with costs to the farmers. In this regard, soil carbon certificates could provide a much-needed financial incentive: Farmers register their fields with commercial providers who certify any SOC increase achieved during a set period of time. The certificates are then sold on the voluntary carbon-offset market. We analysed the suitability of soil carbon certificates for climate change mitigation from the perspectives of soil sciences, agricultural management, and governance. In particular, we addressed questions of quantification, additionality, permanence, changes in emissions, leakage effects, transparency, legitimacy and accountability, as well as synergies and trade-offs with other societal targets.

Soil properties and the mechanisms by which carbon is stored in soils have strong implications for the assessment. Soils have a limited storage capacity, and SOC is not sequestered but its SOC stocks are the dynamic result of plant derived inputs and losses mainly in the form of microbial respiration. The higher the SOC stock, the higher the annual carbon inputs that is needed to maintain it. If carbon friendly management is discontinued, elevated SOC levels will therefore revert to their original level.

We found that while changes in agricultural management that increase SOC are highly desirable and offer multiple-co benefits with climate change adaptation, soil carbon certificates are unsuitable as a tool. They are unlikely to deliver the climate change mitigation they promise as certificate providers cannot guarantee permanence and additionality of SOC storage over climate relevant time-frames. Where the certified carbon storage is non-permanent or fails to meet criteria of additionality, the use of such certificates to advertise products as “carbon-neutral” may be construed as false advertising.

How to cite: Paul, C., Don, A., Bartkowski, B., Wiesmeier, M., Weigl, S., Mayer, S., Steffens, M., Wolf, A., Dönmez, C., and Helming, K.: Suitability of soil carbon certificates for climate change mitigation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10433, https://doi.org/10.5194/egusphere-egu22-10433, 2022.

15:34–15:40
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EGU22-8598
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ECS
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Virtual presentation
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Mario Al Sayah, Pierre-Antoine Versini, and Daniel Schertzer

With the advances of the Nature-Based Solutions (NBS) concept, much attention is being given to its potential for climate change adaptation. Accordingly, Nature-Based adaptation Solutions (NBaS) have become central elements for action on climate. In the EU, the Horizon 2020 (H2020) program translates the ambition of positioning Europe as the world’s leader in NBS. In an effort to draw a comprehensive roadmap of these efforts, this study investigates 21 H2020 projects that utilize NBaS throughout different ecosystems. The main objectives of this study are to provide an inventory of current knowledge, to extract identified risks and knowledge limitations, and to propose future research orientations.

For this purpose, the CORDIS database was used to identify the relevant projects. Using the keyword nature-based solutions and through a rigorous search of research topics and programs, the following projects were retained (based on the existence of deliverables at the time of this study): CLEARING HOUSE, CLEVER Cities, Connecting Nature, DRYvER, EdiCitNet, EuPOLIS, FutureMARES, GrowGreen, NAIAD, Nature4Cities, NATURVATION, OPERADNUM, PHUSICOS, proGIreg, RECONECT, REGREEN, RENATURE, ThinkNature, UNaLab, Urban GreenUP and URBiNAT. Consequently, 137 deliverables were individually examined. Numerous findings were then obtained. These were divided into general and specific results.

In terms of general results, the definition of the NBS concept is still debated: some projects adopt the EC’s definition, others compare between the EC’s and the IUCN’s definition, while many reformulate their own. Second, the continental geographical gradient of pilot sites follows a dense South-West orientation in contrast to a less developed North-Eastern line. In terms of target ecosystems, 61% of the projects target the urban realm, while freshwater ecosystems come second. The coastal, natural and mountainous environments are the least addressed. The focus on urban systems makes most of the generated knowledge, designed solutions and monitoring methods more or less restricted to this realm, hence not necessarily applicable in other settings. Regarding climatic challenges, urban heat islands and floods came first. These are followed by sea level rise, intense precipitation, heat stress, storms, erosion and landslides.

In terms of specific findings, current knowledge and limitations were grouped in-depth per ecosystem (urban, freshwater, marine-coastal, mountainous, forest-natural, and agricultural) and per main research topics (climate change adaptation, risks of oversimplification, system complexity, uncertainty, the scale quandary, progress measuring-monitoring, and disservices). On this basis, several research perspectives were then proposed. Accordingly, interest in NBS-NBaS should extend beyond the urban ecosystem, while deeper knowledge on nature (the physical fundamentals of the N) in NBS-NBaS is needed. It is also important to understand if NBaS are intended to withstand weather change and/or climate change. For the implementation of wide-scale solutions, an extension beyond conservationism is needed, and a better accommodation of uncertainties is required. Therefore, understanding ecosystem tipping points, thresholds, and the resource efficiency of NBaS is primordial. Finally, it is crucial to acknowledge that both ecosystem development and climate change will keep progressing throughout the existence of NBaS. Therefore, the interacting co-evolution of ecosystems, NBaS and climate change should be further studied where their interaction could be forgotten.

How to cite: Al Sayah, M., Versini, P.-A., and Schertzer, D.: A systematic analysis of Horizon 2020 Nature-Based adaptation Solutions projects, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8598, https://doi.org/10.5194/egusphere-egu22-8598, 2022.

15:40–15:46
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EGU22-9109
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Virtual presentation
Dr. Karen Sudmeier-Rieux and the Co-authors

Calls are rising for ecosystems, or green infrastructure, to complement engineered infrastructure for more effective disaster risk reduction and climate governance. Key international framework agreements, including the Sendai Framework for Disaster Risk Reduction 2015-2030 and the 2021 Glasgow Pact, noted the importance of ensuring the integrity of all ecosystems in addressing climate change and disaster risk. For example, vegetation can stabilize slopes to reduce mountain hazards and sand dunes, mangroves, and/or seagrasses can reduce the impacts of coastal storms.  However, there are gaps in the scientific evidence on this topic with few comprehensive, peer-reviewed studies to support decision-making on green infrastructure for disaster risk reduction.

This study systematically reviews 529 English-language articles published between 2000 and 2019. The objective was to catalogue the extent of knowledge and confidence in the role of ecosystems in reducing disaster risk. The main question this review addresses is: What is the evidence of the role that ecosystem services and/or functions contribute to disaster risk reduction? We modified the review methodology established by the Intergovernmental Panel on Climate Change to identify the robustness of evidence and level of agreement on the role of ecosystems in attenuating most common types of hazards.

The data demonstrate very robust links on the role of ecosystems in forest fire management, urban flooding and slope stabilization to reduce mountain hazards in a cost-effective manner. The study also highlights how ecosystems provide multiple services and functions in addition to regulating hazards, e.g., provisioning services for reducing vulnerability. The review highlights several research gaps, notably a geographic concentration of studies on urban areas of Europe and North America, and insufficient policy-relevant research on coastal, dryland, and watershed areas, especially in Asia, Africa and Latin America. To conclude, more attention should be paid to filling these research gaps and developing performance standards, which would provide policy-makers with increased confidence in investing in green infrastructure for disaster risk reduction and climate governance.

How to cite: Sudmeier-Rieux, Dr. K. and the Co-authors: Ecosystems for disaster risk reduction: what is the scientific evidence?, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9109, https://doi.org/10.5194/egusphere-egu22-9109, 2022.

15:46–15:52
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EGU22-1978
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ECS
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On-site presentation
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Amir Gholipour, Elizabeth Duarte, Rita Fragoso, Ana Galvao, and David Christian Finger

Nature-Based Solutions (NBSs) like Sludge Treatment Reed Beds (STRBs) can address resource recovery from sewage sludge in urban and rural areas to boost circular economy and to mitigate climate change. To ensure successful implementation of STRBs, an evaluation of stakeholders’ perceptions can be helpful to identify relevant barriers and opportunities. In this study, semi-structured interviews were conducted with relevant stakeholders, which were categorized in 5 interest groups including academics, state and governments, NGOs, water companies and local communities across Iceland. The interviews were then transcribed and effective elements influencing STRB technology in Iceland were identified through an open-coded method on the transcriptions. The elements were categorized as independent elements (NBS actors, on-going projects, feasibility, legal, economic, sociological, and natural criteria), which were grouped into 7 classifications impacting dependent elements (relevant aspects of STRB, STRB services and system cost). Through Causal Diagrams (CDs), the impact of the independent elements was visualized on the dependent elements. The result of the study is exposed in 8 causal networks and 4 aggregated CDs for sustainability, climate change, biodiversity and circular economy together with mediators interpreting the impacts. The complexity of multi-sequenced causalities of a heterogeneous nature is depicted in CDs implying by stakeholders’ reports and expectations. The study exposes information on the compatible aspects, where further research is required to facilitate the use of STRB for the resource recovery of sewage sludge in Iceland. Therefore, our findings can enable decision makers with intracommunity information to identify elements impacting STRB application, in which the influence of the multiple groups of interests is regarded. 

 

Keywords: Nature-Based Solutions; Sludge Treatment Reed Beds, Resource Recovery, Causal Diagram, climate change, circular economy, sustainability

How to cite: Gholipour, A., Duarte, E., Fragoso, R., Galvao, A., and Christian Finger, D.: Mapping NBS stakeholders’ perspective over Sludge Treatment Reed Bed (STRB) in Iceland, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1978, https://doi.org/10.5194/egusphere-egu22-1978, 2022.

15:52–15:58
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EGU22-7415
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ECS
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Virtual presentation
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Hnin Wuit Yee Kyaw and Zita Sebesvari

Multiple disaster risks are interconnected and are commonly caused by ecosystem degradation. Ecosystem degradation also drives many of the world's major problems, including biodiversity loss, climate change, and poverty. Ecosystem-based solutions such as ecosystem-based adaptation, biodiversity conservation, and community forestry are increasingly implemented in various contexts. However, little is known about possible interlinkages, synergies, and trade-offs among those ecosystem-based responses and potential barriers to their integration. This study explores spatial and conceptual synergies and trade-offs among ecosystem-based adaptation, biodiversity conservation, and community forestry and the barriers to implementing integrated actions.

The study was located in Ayeyarwady Delta, Myanmar. The research first used a comprehensive socio-ecological risk assessment framework and multi-risk impact chains to understand high-risk areas and identify potential areas for ecosystem-based adaptation. Potential areas for biodiversity conservation and community forestry respectively were then identified using criteria developed based on a literature review. At this point, spatial autocorrelations were tested, and a modified t-test was used to identify spatial relationships among them. Finally, qualitative expert interviews were conducted, and content analysis was used to understand conceptual synergies, trade-offs, and potential barriers for integrated action.

Results show potential for both social and ecological synergies. Ecosystem-based adaptation and biodiversity conservation show synergies with community forestry in the areas of local governance, and the relevance of social factors such as multi-stakeholder awareness, indigenous knowledge, land tenure security, community rule-making and ownership, and biodiversity-friendly livelihoods. Synergies between ecosystem-based adaptation and biodiversity conservation are mostly related to ecological factors such as benefits for biodiversity, ecosystem health, and corridor and buffer functions. Moreover, significant spatial synergies were observed between community forestry and biodiversity conservation areas.

Despite synergies, trade-offs exist and are mainly linked to social inequalities and the use of biodiversity-damaging practices. Spatial trade-offs occur between ecosystem-based adaptation and community forestry due to a lack of land tenure security in high-risk townships. Conceptual trade-offs between ecosystem-based adaptation and community forestry are mainly linked to inequality, lack of access, local power relations, and land tenure insecurity. Trade-offs between biodiversity and the other two are observed due to the use of monocultures, exotic species, and clear-cutting practices. Legal, social, and financial barriers have been identified for the implementation of synergetic actions, while proper facilitation, community rule-making, and biodiversity-friendly livelihoods are key enabling factors in achieving sustainable ecosystem restoration.

This research argues that ecosystem-based adaptation, biodiversity conservation, and community forestry benefit each other, highlighting that fostering those synergies is key for ecosystem restoration and conservation in the face of climate change, biodiversity loss, and poverty. Furthermore, the research stresses the need to consider community governance and biodiversity aspects in ecosystem-based adaptation to address societal challenges.

How to cite: Wuit Yee Kyaw, H. and Sebesvari, Z.: Assessment of synergies and trade-offs among ecosystem-based adaptation, biodiversity conservation and community forestry in Ayeyarwady Delta, Myanmar, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7415, https://doi.org/10.5194/egusphere-egu22-7415, 2022.

15:58–16:04
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EGU22-10493
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Virtual presentation
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Maria Carmen Garcia Mateo and Nico Tillie

Globally, there is clear evidence that unsustainable urbanisation and climate change are pressing challenges for our systems. Nature-based Solutions are starting to be considered as a mechanism to help underpin and tackle societal and global challenges such as biodiversity loss, ecosystem depletion, resource use or human and ecological well-being. Nevertheless, still disciplines are working separately and enabling the co-design of Nature-based Solutions to reach sustainable urban planning in cities is far to be considered for climate adaptation and climate neutrality in cities. Therefore, the study intends to overcome those research gaps mentioned. On the way to tackle those issues, the paper frames the necessity to align science, policy and society goals to reach a sustainable future and bring sectors together to ensure and help build an inclusive, healthy and a resilient world. The methodology is based on a systematic review process where we explore the state of the art on the matter. This paper intends to open the discussion of a holistic, systemic and comprehensive approach to mainstreaming Nature-based Solutions  and  presents a novel pathway for transdisciplinary climate and environmental planning action. A novel conceptualization; socio-ecological and environmental-economic framework for Nature-based Solutions action plan with defined key principles to enable the mainstreaming of nature-based solutions into policies and governance. The study recommends and proposes specific nature-based solutions strategies to underpin the lack of coherence that sometimes shows in some approaches when designing and planning cities, implementing policies for sustainable urban planning and design, facilitating ecosystem restoration and human well-being. To reach an environmentally, socially, economically, locally, ecologically and politically sustainable, circular and resilient Europe by 2030 to help deliver the global policy agendas and the European Green Deal and its strategies.

How to cite: Garcia Mateo, M. C. and Tillie, N.: Enabling the mainstreaming of nature-based solutions into policy-making and governance: Holistic and systemic approach and coherence across policies to build a sustainable, circular and resilient planet and tackle societal challenges, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10493, https://doi.org/10.5194/egusphere-egu22-10493, 2022.

16:04–16:10
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EGU22-7019
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ECS
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Virtual presentation
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Hung-En Li and Su-Ting Cheng

In the face of climate change, the government of Taiwan requires new mitigation policies and implementation strategies. As forest plantations are commonly accepted as great carbon sinks, developing reliable carbon systems linking forestry carbon sequestration into green carbon credits in the economic sector requires synergic integration to examine potential carbon sink capability of forest plantations under the ever-changing climate. In this regard, this study developed a process-based stand growth model based on the structure of the Physiological Principles for Predicting Growth (3-PG) for carbon sequestration estimations of Sugi plantations in the National Taiwan University (NTU) Experimental Forest. The model considered monthly solar radiation, temperature, precipitation, vapor pressure deficit (VPD), and the atmospheric carbon dioxide concentration to simulate dynamic biomass production, and then allocated the simulated biomass to root, stem, and foliage by allometric equations fitted to biomass data from the SugiHinoki Database. After that, the mortality of stand was determined by using a zero-inflated Poisson modelling on long-term growth data collected by the NTU Experimental Forest during 1921-2019. In addition, we performed a scenario analysis to forecast future stand growth under 4 climate scenarios of RCP2.6, RCP4.5, RCP6, and RCP8.5. Results revealed higher annual biomass increment (around 4 t ha-1y-1) in the end of the century in RCP6.0 and RCP8.5, and lower increment (around 2.5 t ha-1y-1) in RCP2.6 and RCP4.5. A step-wise multiple linear regression analysis on the simulated growth data and climatic inputs revealed stronger positive impact of CO2 concentration than precipitation on unit biomass primary production (NPP/Biomass). Temperature had comparable counter impact against precipitation, and solar radiation showed the least negative influence on unit biomass primary production. Based on this process-based stand growth model, we are able to dig into the relation between climatic variables and carbon sequestration rate, and help sketch prospect of plantations in the carbon market for plantation managers, investors, and policy makers.

How to cite: Li, H.-E. and Cheng, S.-T.: Forecasting impacts of climate change on plantation carbon sink capability, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7019, https://doi.org/10.5194/egusphere-egu22-7019, 2022.

16:10–16:16
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EGU22-7324
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ECS
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On-site presentation
Ziyan Zhang, Athanasios Paschalis, Ana Mijic, Barnaby Dobson, and Adrian Butler

Globally, urban areas will face multiple water-related challenges in the near future. The main challenges are intensified droughts leading to water scarcity, increased flood risk due to extreme rainfall intensification, increased total water demand due to an increasing urban population, amplified urban heat island intensities due to urban sprawl, and reduction in urban carbon sink due to plant water stress. Urban greening is an excellent option for mitigating flood risk and excess urban heat. Meanwhile, rainwater harvesting (RWH) systems can cope with water supply needs and urban water management. In this study, we investigated how urban greening and RWH can work together to mitigate the aforementioned risks. We evaluate the joined-up management approach under climate projections for 30 cities in the USA spanning a variety of climates, population densities and urban landscapes. By incorporating a new RWH module in the urban ecohydrological model UT&C and flexible operational rules of reusing harvested water for domestic use and urban green space irrigation, we tested 4 intervention approaches: control, RWH installation, urban greening supported by RWH, and urban greening supported by traditional irrigation (i.e., supplying via mains water). Each intervention approach was evaluated using our adapted version of UT&C and forced by the last generation convection-permitting model simulations of current (2001-2011) and end-of-century (RCP8.5) climate from Weather Research and Forecasting (WRF). The volume of RWH is assumed to be 2000L per household for all cities. Results showed that neither urban greening nor RWH could contribute significantly to reducing the expected increase in canyon temperature, because of the strong change in background climate (i.e., increases in average atmospheric temperature). However, RWH alone can sufficiently reduce the intensifying surface flood risk and effectively enhance water conservation, and urban greening can significantly increase the carbon sink of cities especially in dry regions, and if supported by traditional irrigation. Those results vary with the background climate: the benefits of urban greening, either supported by RWH or traditional irrigation, on canyon temperature reduction and carbon sink improvement increased with average air temperature and decreased with wetness index respectively; the benefits of RWH on runoff reduction and water conservation are both positively dependent on local annual precipitation.

How to cite: Zhang, Z., Paschalis, A., Mijic, A., Dobson, B., and Butler, A.: Assessing co-benefits of urban greening coupled with rainwater harvesting management under current and future climates across USA cities, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7324, https://doi.org/10.5194/egusphere-egu22-7324, 2022.

16:16–16:22
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EGU22-7997
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ECS
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Virtual presentation
Heba Marey, György Szabó, and Gábor Kozma

 

Abstract

The challenges posed by the growth of urbanization in Egypt and the development of new cities play an essential role in applying the circular economy (CE) in the construction materials sector and the priorities for promoting sustainable construction activities in the future. Therefore, the construction sector has many adverse environmental impacts on energy and natural resources consumption. Starting from materials production, operation until disposal to landfills. Consequently, the industry is considered one of the most consumers of non-renewable resources and producer of CO2 emissions. On the other hand, applying Nature-based solutions (NbS) to enhance sustainability by protecting the ecosystems and maintaining economic benefits plays a vital role, especially for new Egyptian cities. The research aims to investigate the role of applying NbS for achieving CE in construction materials and eliminate its negative impact in the scope of three factors:  green building materials, waste management systems, renewable energy use. The current research attempts to answer how NbS can improve the CE and reduce environmental impacts of the construction materials sector. Therefore, the SOWT analysis investigated the strengths, opportunities, weaknesses, and threats of using the NbS strategies for three different construction sites in Egypt. Furthermore, the survey questionnaire was applied to identify the interactions between the parameters derived from 40 participants such as consultants, architecture engineers, civil engineers, site engineers, project managers and review the previous research efforts. As a result, a conceptual framework was created for the construction materials considering reduce, reuse, recycle, recovery, and disposal, to identify the impact of the implementation of NbS on achieving sustainable development strategies in the Egyptian construction sector. The result showed that the NbS could effectively promote the construction sector and achieve environmental and economic benefits, which consequently help the transition to CE. Therefore, there is the necessity for developing new sustainable policies and cooperation between public and private sectors to support the investments of sustainable strategies in the construction materials market and increase Egyptian society's awareness of the benefits of NbS in economic, environmental, and social aspects.

 Keywords, Nature-based solution, Construction materials, Circular Economy, Egypt 

How to cite: Marey, H., Szabó, G., and Kozma, G.: Using the Nature-Based Solutions for Applying Circular Economy for the Construction Materials Sector in Egypt, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7997, https://doi.org/10.5194/egusphere-egu22-7997, 2022.

16:22–16:28
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EGU22-13010
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Virtual presentation
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Marta Vicarelli, Michael Kang, Madeline Leue, Aryen Shrestha, David Wasielewski, Karen Sudmeier-Rieux, Jaroslav Mysiak, Simon Schütze, Michael Marr, Shannon McAndrew, and Miranda Vance

Ecosystems and ecosystem services are key to helping achieve reduction in disaster risk, sustainable development, and climate change adaptation, and this is now recognized by major international framework agreements (Convention on Biological Diversity, 2014; United Nations Office for Disaster Risk Reduction, Sendai Framework for Disaster Risk Reduction, 2015-2030). However, there is limited knowledge about the cost efficiency and socio-economic equity outcomes of Nature-based Solutions (NbS) compared to traditional engineered strategies.

In this study we developed a global database of more than 130 peer-reviewed studies, published between 2000 and 2020, that perform economic evaluations of NbS for Ecosystem-based Climate Adaptation (EbA) and Ecosystem-based Disaster Risk Reduction (Eco-DRR). Using meta-analysis techniques, we assess the existing scientific knowledge on the economic viability and performance of NbS for Eco-DRR and EbA, cataloguing outcomes both in terms of degree of economic efficiency and social equity. Our analysis includes multiple dimensions: geographic distribution of the published studies, types of ecosystems and ecosystem services evaluated, hazards and climate impacts analyzed, and economic methodologies used to perform economic efficiency evaluations (e.g., cost benefit analysis, stated/revealed preferences evaluation methods).

This study builds on a recent global assessment (Sudmeier-Rieux et al, 2021) that performs the first systematic review of Eco-DRR peer-reviewed studies across all disciplines. Their results show robustness of evidence and level of agreement on the role of ecosystems in attenuating 30 types of hazards, based on the assessment methodology established by the Intergovernmental Panel on Climate Change (IPCC). Our meta-analysis expands the 2021 review by evaluating the economic benefits associated with Eco-DRR and NbA approaches; by examining cost efficiency of Eco-DRR and NbA interventions compared to traditional engineering solutions; by performing equity assessments of the outcomes; and by studying how the NbS interventions reviewed contributed to the sustainable development goals (SDGs).

REFERENCE:

Sudmeier-Rieux, K., Arce-Mojica,T., Boehmer, H.J., Doswald, N., Emerton, L., Friess, D.A., Galvin, S., Hagenlocher, M., James, H., Laban, P., Lacambra, C., Lange, W., McAdoo, B.G., Moos, C., Mysiak, J., Narvaez, L., Nehren, U., Peduzzi, P1., Renaud, F.G., Sandholz, S., Schreyers, L., Sebesvari, Z., Tom, T., Triyanti, A., van Eijk, P., van Staveren, M., Vicarelli, M., Walz, Y. "Scientific evidence for ecosystem-based disaster risk reduction." Nature Sustainability (2021): 1-8. 

How to cite: Vicarelli, M., Kang, M., Leue, M., Shrestha, A., Wasielewski, D., Sudmeier-Rieux, K., Mysiak, J., Schütze, S., Marr, M., McAndrew, S., and Vance, M.: Scientific evidence of the economic benefits of ecosystem-based disaster risk reduction and ecosystem-based climate change adaptation, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-13010, https://doi.org/10.5194/egusphere-egu22-13010, 2022.

Coffee break
Chairpersons: Claudia Wieners, Herman Russchenberg, Henk A. Dijkstra
17:00–17:06
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EGU22-11878
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On-site presentation
Henrik Vestergaard Poulsen, Sander Bruun, Cecilie Skov Nielsen, and Søren Kolind Hvid

Nitrous oxide (N2O) emitted from agricultural soils makes up a significant part of the collective agricultural greenhouse gas (GHG) emissions. These emission are to a large extent caused directly or indirectly by the application of nitrogenous fertilizer and there is a strong demand for mitigation strategies.

 

Nitrous oxide is produced in the soil in a range of different processes but mainly in microbial nitrification and denitrification. A number of factors exert influence on these microbial processes in the soil, most notably the oxygen concentration, availability of ammonium and nitrate, available organic matter and diffusivity, and fairly advanced process-based simulation models are often used in attempts to simulate the amount of N2O emitted. Here we propose using more a simplistic modelling approach to provide a novel risk assessment tool for nitrogenous fertilizer applications to be implemented in Danish farmers field management programmes.

 

At SEGES Innovation we have unique database access to field activity data from Danish farmers - e.g. crop sequence, fertilizer applications, residue handling, soil texture - covering more than 85 % of the Danish cultivated area. Based on these data and field specific climate data, a soil water balance model (Plauborg et al. 1995) and soil organic carbon model (Taghizadeh-Toosi et al. 2014) are running in daily timesteps for all fields in the database. These models provide, respectively, the daily level of WFPS in the soil and the organic matter turnover rate in the soil simulated during the weather forecast period of 10 days. Those two outputs are combined with a simulated soil temperature in a simplified version of the NGAS-model (Parton et al. 1996) to give a rough simulated N2O-emission for any planned fertilizer application throughout the weather forecast period.

 

The risk assessment tool exhibits this daily simulated N2O-emission as a risk evaluation of fertilizer application to the farmer in field management programmes, where future field activities are entered and logged. The objective is to lower the GHG emission by reducing the number of fertilizer applications right at peak N2O-emission conditions, once the farmers are presented with this information.    

How to cite: Vestergaard Poulsen, H., Bruun, S., Skov Nielsen, C., and Kolind Hvid, S.: N2O-emission risk assessment tool for nitrogenous fertilizer applications, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11878, https://doi.org/10.5194/egusphere-egu22-11878, 2022.

17:06–17:12
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EGU22-11364
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ECS
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Virtual presentation
Large-scale siting of sand dams: a participatory approach and application in Angolan drylands
(withdrawn)
Luigi Piemontese, Giulio Castelli, Natalia Limones, and Elena Bresci
17:12–17:18
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EGU22-1956
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ECS
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Virtual presentation
Yijia Wang, Yanxu Liu, Xutong Wu, Xinsheng Wang, Ying Yao, and Bojie Fu

Facing the dual threats of climate and socio-economic changes, how the social-ecological systems (SES) in the Tibet Autonomous Region can seize the opportunity of ecological restoration to enhance the quality of the environment while improving the relationship between human and nature is of great significance to promote the regional sustainable development. Thus, regarding human as the key component, we used Ostrom’s SES framework as an analytical fundation to analyze the impact of the implementation of ecological engineering on local human-policy-resource connection. We distributed questionnaires for local residents, distinguished experimental groups (EG, n=325) and control groups (CG,n =165), and used a network approach to construct indicators for assessing effectiveness of ecological engineering, including overall connectivity and evenness. Meanwhile, random forest regression was used to explore the background variables of the dominant connection and accordingly proposed subsequent directions for optimal governance. We found that interviewees in areas where ecological engineering was implemented had more positive perceptions of the importance of ecosystem services, the relationship between ecological conservation and well-being, attitudes toward ecological engineering, and the impact of measures. The overall connectivity and evenness of EG were significantly higher than that of CG. The implementation of ecological engineering enhanced the connection between local people and the environment, but caused some inconvenience to local residents’ livelihoods. Besides, elevation and annual precipitation were the background variables that dominated the overall connectivity. The overall connectivity was lower in alpine steppes with elevation of around 4000 m and semi-arid areas with annual precipitation around 400-500 mm. The implementation of ecological engineering played a positive role in alleviating human-nature relationship in tensions and promoting collective governance of common pool resources, but the governance process still involved risks. Safeguarding and improving the residents’ livelihoods and enhancing the regional weak SES coupling due to geographical constraints are the future directions for optimal governance.

How to cite: Wang, Y., Liu, Y., Wu, X., Wang, X., Yao, Y., and Fu, B.: The implementation of ecological engineering in Tibet has strengthened the local human-policy-resource connection, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1956, https://doi.org/10.5194/egusphere-egu22-1956, 2022.

17:18–17:24
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EGU22-9838
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Highlight
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Presentation form not yet defined
Carbon Dioxide Removal and warming reversal in the light of uncertain Earth System processes
(withdrawn)
Carl-Friedrich Schleussner, Joeri Rogelj, Thomas Frölicher, Andrew MacDougall, Benjamin Sanderson, and Quentin Lejeune
17:24–17:30
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EGU22-8269
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ECS
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Virtual presentation
Ali Asaadi, Jörg Schwinger, Hanna Lee, Jerry Tjiputra, Vivek Arora, Roland Séférian, Spencer Liddicoat, Tomohiro Hajima, Yeray Santana-Falcòn, and Chris Jones

Limiting global warming to 1.5°C by the end of the century currently seems to be an ambitious target which will potentially be accompanied by a period of temperature overshoot. Achieving this climate goal might require massive carbon dioxide removal on large scales. Regardless of the feasibility of such removals, their effects on biogeochemical cycles and climate are not well understood. Changes in atmospheric CO2 concentration ([CO2]) and climate alter the CO2 exchange between the atmosphere and the underlying carbon reservoirs of land and ocean. Carbon-concentration and carbon-climate feedback metrics are useful tools for quantifying such changes in the carbon uptake by land and ocean, currently acting as a sink of carbon. We investigate the changes in carbon feedbacks under overshoot scenarios that could influence mitigation pathways to achieve the temperature goal. An ensemble of Coupled Model Intercomparison Project 6 (CMIP6) Earth system models that conducted an idealized ramp-up and ramp-down experiment (1pctCO2, with increasing and later decreasing [CO2] at a rate of 1% per year) has been used and compared against a scenario simulation involving negative emissions (SSP5-3.4-OS). The analyses are based on results from biogeochemically coupled (where land and ocean respond to rising CO2 levels but the climate is kept constant) and fully coupled simulations. For the positive emission phases, the model-mean global average carbon-climate feedback looks roughly similar between the SSP5-3.4-OS and the 1pctCO2 simulations, with a gradual monotonic decreasing behavior in absolute values which translates to a reduction in land and ocean uptakes. The carbon-concentration feedback in SSP5-3.4-OS is larger than in the 1pctCO2 simulations over the ocean. Both the ocean and land simulate an increase in carbon uptake during the ramp-up, while during the ramp-down, their uptakes show a hysteresis behavior. This feature is more prominent in the idealistic 1pctCO2 experiment with a higher [CO2] growth rate and without land use change effects than in the more realistic SSP5-3.4-OS scenario. Also, the time evolution of the global annual carbon-concentration and carbon-climate feedbacks seem to be very similar over natural land areas. In addition, changes in carbon fluxes are compared over the high latitude permafrost and non-permafrost regions in the Northern Hemisphere. Over land, the carbon-concentration feedback metric is decomposed into different terms to investigate the contributions from changes in live vegetation carbon pools and soil carbon pools. This indicates that the feedback is dominated by the residence time of carbon in vegetation and soil. Furthermore, building on previous studies, feedback metrics are also calculated using an alternative approach of instantaneous flux-based feedback metrics to further compare differences between models. The difference between the two approaches can be seen more obviously in the geographical distribution of the two feedbacks, especially for the negative emission phases of the 1pctCO2 experiment.

How to cite: Asaadi, A., Schwinger, J., Lee, H., Tjiputra, J., Arora, V., Séférian, R., Liddicoat, S., Hajima, T., Santana-Falcòn, Y., and Jones, C.: Carbon cycle feedbacks in an idealized and a scenario simulation of carbon dioxide removal in CMIP6 Earth system models, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8269, https://doi.org/10.5194/egusphere-egu22-8269, 2022.

17:30–17:36
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EGU22-6126
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ECS
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On-site presentation
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Moritz Adam, Thomas Kleinen, Matthias M. May, Daniel Lörch, Arya Samanta, and Kira Rehfeld

Without substantial decarbonization of the global economy, rising atmospheric carbon dioxide (CO2) levels are projected to lead to severe impacts on ecosystems and human livelihoods. Integrated assessments of economy and climate therefore favour large-scale CO2 removal to reach ambitious temperature-stabilization targets. However, most of the proposed approaches to artificially remove CO2 from the atmosphere are in conflict with planetary boundaries due to land-use needs and they may come with unintended climatic side-effects. Long-term draw-down of CO2 by photoelectrochemical (PEC) reduction is a recent and promising approach that potentially entails a very low water footprint and could offer a variety of carbon sink products for safe geological storage. For renewable hydrogen fuel production, PEC devices have already been demonstrated to deliver high solar-to-fuel efficiencies. If such devices are adjusted to deliver high solar-to-carbon efficiencies for carbon dioxide removal, they would require comparably little land for achieving annual sequestration rates that are compatible with limiting global warming to 2°C or below. Yet, no production-scale prototype exists and the climatic side-effects of such an "artificial photosynthesis'' approach for negative emissions are unknown. Here, we discuss our work towards investigating potential impacts of PEC CO2 removal on the climate and the carbon cycle in simulations with the comprehensive Earth System Model MPI-ESM. We designed a scheme to represent hypothetical PEC devices as a land surface type which is influencing land-atmosphere energy and moisture fluxes. We parameterize the irradiation-driven carbon sequestration of the devices and interactively couple their deployment area and location to a negative emission target. We plan to compare the potential side-effects between scenarios of dense, localized deployment and spread-out, decentralized application. These scenarios represent different guiding objectives for deploying hypothetical PEC systems such as maximizing the insolation per module area, or mitigating the overall impacts on climate and on carbon stocks. For the different scenarios, we intend to investigate changes in the surface balances, which could impact atmospheric circulations patterns. We further plan to quantify the amount of land-stored carbon that is relocated due to land-use change, as this affects the amount of CO2 that can effectively be withdrawn from the atmosphere. Finally, we relate theoretical expectations for area requirements and CO2 withdrawal with results from the coupled simulations which could inform the technological development. While ambitious emission reductions remain the only appropriate measure for stabilizing anthropogenic warming, our work could advance the understanding of possible benefits and side-effects of hypothetical PEC CO2 removal.

M. M. May & K. Rehfeld, ESD Ideas: Photoelectrochemical carbon removal as negative emission technology. Earth Syst. Dynam. 10, 1–7 (2019).

How to cite: Adam, M., Kleinen, T., May, M. M., Lörch, D., Samanta, A., and Rehfeld, K.: Investigating potential climatic side-effects of a large-scale deployment of photoelectrochemical devices for carbon dioxide removal, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-6126, https://doi.org/10.5194/egusphere-egu22-6126, 2022.

17:36–17:42
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EGU22-4699
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ECS
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On-site presentation
Manon Berger, Laurent Bopp, David T. Ho, and Lester Kwiatkowski

Carbon dioxide removal (CDR) has become part of the portfolio of solutions to mitigate climate change. In combination with emission reductions, CDR may be critical to achieving the goal of limiting global warming to below 2°C, as outlined in the Paris Agreement. Due to its potential high productivity and environmental co-benefits, macroalgae cultivation has recently become a prominent ocean-based CDR strategy. However, estimates of the CDR potential of large-scale deployment are highly limited. Here we simulate idealized global deployment of macroalgae-based CDR using the NEMO-PISCESv2 ocean biogeochemical model at high spatial resolution (0.25° nominal horizontal resolution). Macroalgae growth is confined to the upper 100m of the water column in Exclusive Economic Zones (EEZ) free of sea ice and with an appropriate nitrate/phosphate regime. Although the loss of dissolved inorganic carbon (DIC) through macroalgal growth enhances the flux of atmospheric carbon into the ocean, this increase in carbon uptake is less than the rate of macroalgal production. In the absence of any nutrient limitation on growth, the enhancement in ocean carbon uptake is only 73-77% of the carbon lost from the water column due to macroalgal production. However, when macroalgae nutrient limitation/uptake is additionally accounted for, the increase in ocean carbon uptake accounts for only 41-42% of the potential carbon lost through macroalgae production. These inefficiencies are due to ocean transport replacing part of the DIC lost in the upper water column with DIC from depth, the influence of local nutrient concentrations on the vertical profile of macroalgal production, and feedbacks on the nutrient resources available for phytoplankton net primary production. CDR efficiency is shown to scale near-linearly between scenarios assuming 1% to 10% of the global EEZ area is cultivated for macroalgae. The efficiency of macroalgal CDR shows significant regional variability, with much of the enhancement in ocean carbon uptake (43%-46%) occurring outside EEZs, posing potential difficulties to national scale accounting.

How to cite: Berger, M., Bopp, L., Ho, D. T., and Kwiatkowski, L.: Assessing global macroalgal carbon dioxide removal potential using a high-resolution ocean biogeochemistry model, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4699, https://doi.org/10.5194/egusphere-egu22-4699, 2022.

17:42–17:48
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EGU22-10608
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On-site presentation
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John Allen, Calum Fitzgerald, and Lonnie Franks

A new nature based solution for capturing the entire man-made emission of carbon dioxide per year and locking it away in the deep ocean, called ECOPIATM, has been devised by a marine think tank, MyOcean Resources Ltd. This is a global solution to the anthropogenic climate change problem, without environmental downsides - it provides the fix. By using the characteristics of the Ocean, ECOPIATM removes the excess atmospheric CO2, de-acidifies the ocean’s waters, creates new sustainable fisheries, and most importantly allows the economies of the world to continue to grow and prosper.

ECOPIATM is able to address the anthropogenic climate change problem whilst having a positive global impact on economic growth. It enables continued economic growth for all nations by balancing the problem of excess atmospheric CO2 rather than following strategies that require a reduction in economic activities. Trying to reduce the amount of excess CO2 emitted by economies can be considered the biggest waste management issue the world has to solve; however current strategies have had trouble getting traction due to their negative impact on economic growth. 

By transillumination of the giant deserts of the Ocean, we can reduce the amount of atmospheric CO2 at the same time as de-acidifying the oceans, by empowering natural oceanic primary productivity simply through the provision of light. This allows ECOPIATM to be an effective CO2 waste management solution for the atmosphere. Rather than having to harm economic growth through difficult to achieve emissions reductions, companies can work with ECOPIATM to genuinely offset their atmospheric CO2 emissions, through photosynthetic CO2 uptake.

These enormous deserts of the sub-tropical open oceans, one seventh (~ 50 million km2) of the whole of the Earth’s ocean area, are reportedly getting bigger; with productive surface waters being replaced by an increase in the minimally productive surface waters of the oligotrophic gyres, at a rate of 0.8 million km2 per year . ECOPIATM in total only requires 0.2 million km2 of those gyres, just one quarter of the current increase in area per year.

Many of the nature based solutions have significant uncertainties that largely come about from the farming-like practise of changing the composition of the ‘soil’ or in this case the ocean waters. ECOPIATM takes a different approach, that of channelling light down to the depths where there are plenty of naturally determined nutrients and seed population, thus we are no longer ‘farming’ we are simply providing light. Furthermore, as there is no strict geo-engineering involved, ECOPIATM provides no mechanism for a preferential pressure on the naturally determined diversity of the light cultured ecosystem.

It has been noted by the UK's, HRH the Prince of Wales, amongst others, that the global anthropogenic climate change issue can only be solved by Industry. ECOPIATM stands out in that it is self-fundable, both in infrastructure and operational costs, via the use of Carbon Credits at today’s prices, allowing Industry to solve the issue in an affordable way.

How to cite: Allen, J., Fitzgerald, C., and Franks, L.: Earth Climate Optimisation Productivity Island Array (ECOPIATM), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10608, https://doi.org/10.5194/egusphere-egu22-10608, 2022.

17:48–17:54
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EGU22-12467
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Presentation form not yet defined
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Francesco Pietro Campo, Stefano Caserini, and Mario Grosso

The deployment of carbon dioxide removal (CDR) processes is required, as well as strong and immediate emission reductions, to limit the global temperature increase “well below to 2°C above pre-industrial levels” as required by the Article 2 of the Paris Agreement.

Among the CDR processes, ocean alkalinity enhancement (OAE) allows to remove CO2 from the atmosphere and simultaneously to counteract the ongoing ocean acidification caused by the increased CO2 atmospheric concentration. In the framework of the DESARC (DEcreasing Seawater Acidification Removing Carbon) MARESANUS research project, different strategies to produce decarbonized slaked lime (SL), i.e. Ca(OH)2, and to discharge it in the seawater have been evaluated.

The feasibility and the potential of OAE were evaluated at the global scale and at the Mediterranean Sea basin scale. Two different logistic scenarios for the discharge of SL were analyzed: new dedicated ships, and partial load on modified existing dry bulk and container ships. The data on the existing global fleet of vessels and marine routes has been elaborated to assess the potential discharge of SL.

Through the life-cycle assessment methodology, the efficiency of removing CO2 from the atmosphere was evaluated, as well as other potential environmental impacts connected to SL production and transport. The “cradle-to-grave” approach has been applied to different configurations of the process, that consider both biomass gasification and the use of renewables as a source of energy for limestone calcination, as well as eventual CO2/H2 separation and CO2 storage.

The data collected for the life cycle inventory were mainly obtained from the preliminary design of the process and the scientific literature, as well as from the ecoinvent database. According to the environmental footprint method implemented in SimaPro software, sixteen impact categories for assessing the burdens on the environment and human are evaluated, with a particular focus on Climate change, Land use,  and Mineral and metals use.

The results show that for all the analyzed configurations, the process has a potential negative impact on the Climate change category, i.e. there is a benefit for the environment in terms of CO2 removal from the atmosphere. Since the avoided impacts are related to the source for hydrogen, the type of avoided source has a relevant role and is subjected to a sensitivity analysis.

Finally, the availability of limestone for the large-scale development of ocean alkalinisation have been evaluated, considering in particular the deposits of pure limestone near the coastlines, that  could minimize logistic and transportation activities.

Results show that pure carbonate potential resources are of several trillion tons and are not a constraint for the development of global-scale ocean liming. A large part of pure limestone resources is nearby the coastline, in areas with no or low vegetation cover, mainly in North Africa and Iran. Global limestone yearly production is similar to coal, and the required upscaling compared to the current extraction rate is far lower for limestone than for other materials considered for OAE, such as olivine, magnesite and brucite.

How to cite: Campo, F. P., Caserini, S., and Grosso, M.: Feasibility, potential and environmental impacts of ocean alkalinity enhancement for removing CO2 from the atmosphere and counteracting seawater acidification, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12467, https://doi.org/10.5194/egusphere-egu22-12467, 2022.

17:54–18:00
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EGU22-893
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Highlight
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On-site presentation
Barbara Neumann and Lina Röschel

To achieve the ambitious but necessary climate targets set by the Paris Agreement, the IPCC model pathways for limiting global warming to 1.5°C compared to pre-industrial levels make apparent the need for safeguarding and enhancing the natural global carbon sink – including via carbon dioxide removal (CDR). A range of ocean-based CDR approaches, also termed “negative emissions technologies” (NETs), has been proposed to make use of the ocean’s potential to take up carbon dioxide from the atmosphere and store it in water, biomass, and sediments. The governance framework in place to regulate CDR in the ocean, at this time, is limited to the direct and articulate regulation of ocean fertilization. Meanwhile, other NETs such as ocean alkalinity enhancement and artificial upwelling emerge, but a comprehensive and foresight-oriented regulation for the testing or even deploying at larger scale is missing. Specifically, there is large uncertainty on unintended (positive and negative) effects of these technologies on the condition of the ocean, in addition to enhanced carbon uptake and storage, and how these may impede on or support other global sustainability goals. The deployment of NETs in the ocean poses additional governance complexities relating to unknowns, uncertainties, and transboundary issues. In a study that is part of the EU H2020-project OceanNETs, we explore to what extent the current global governance framework directly or indirectly regulates emerging ocean-based NETs and reflect on the particularities and requirements for their comprehensive governance. The analysis considers the gaps, challenges, needs, and opportunities for comprehensive governance of ocean-based NETs. 

How to cite: Neumann, B. and Röschel, L.: Global governance of ocean-based negative emission technologies. Exploring gaps, challenges, and opportunities, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-893, https://doi.org/10.5194/egusphere-egu22-893, 2022.

18:00–18:06
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EGU22-7797
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ECS
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On-site presentation
Gideon Futerman, Martin Janssens, Iris de Vries, John Dykema, Andy Parker, and Hugh Hunt

There are many uncertainties surrounding solar radiation management (SRM), which cannot all be quantified and reduced using models, laboratory experiments or observations of natural analogs such as volcanic eruptions, ship tracks, or dust storms. While there is broad consensus both in- and outside the scientific community that better understanding of the climate system is beneficial to policy makers and society, the value of improved knowledge of SRM has been highly controversial. Yet, it is evident that SRM research can contribute to quantifying and reducing important uncertainties pertaining to fundamental knowledge on the workings of the Earth system, while also providing essential specific knowledge on positive and negative impacts of SRM to inform future decisions.

In 2016, a group of SRM experts gathered at the Institute for advanced sustainability studies in Potsdam for a workshop to formulate a set of low environmental impact SRM experiment proposals. We present these as a non-exhaustive set of possible experiments with no measurable environmental side effects that could provide valuable information that cannot be obtained from models or lab experiments. Both perturbative and non-perturbative experiments are proposed for different SRM methods including marine cloud brightening, stratospheric aerosol injection and cirrus cloud thinning.

It was found that in the time period between 2016 and now several of the research questions addressed in the experiment proposals have been answered by unrelated experimental environmental science studies, whereas no experimental studies have been carried out in the context of SRM. This finding shows that there is significant overlap in high priority research questions and outcomes of non-SRM and SRM environmental research. In addition, it shows that non-controversial environmental science experiments can provide similar SRM-relevant knowledge as dedicated SRM-experiments. Given that one of the main arguments against SRM research is the potential danger of the acquired knowledge, the finding that obtained knowledge of non-SRM and SRM experiments can be similar raises the question which effect the declared relationship to SRM on outdoors research proposal review and regulation should be.

How to cite: Futerman, G., Janssens, M., de Vries, I., Dykema, J., Parker, A., and Hunt, H.: Governance and science implications of low environmental impact outdoors solar radiation management experiments, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7797, https://doi.org/10.5194/egusphere-egu22-7797, 2022.

18:06–18:12
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EGU22-7923
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ECS
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On-site presentation
Alexander Tluk, Iris de Vries, Martin Janssens, and Steven Hulshoff

There are many uncertainties surrounding solar radiation management (SRM), not in the least concerning the technological feasibility of hypothetical deployment scenarios. In sulfate stratospheric aerosol injection (SAI) scenarios, the radiative effectiveness of the aerosol is governed by its size distribution. In turn, aerosol size distribution is governed by the aerosol-precursor injection rate and injection plume conditions. Hence, uncertainties in cost and environmental impact of aircraft-based sulfate stratospheric aerosol injection (SAI) are primarily determined by uncertainties in injection plume conditions. In addition, the climate impacts and side effects of SAI as simulated by climate models depend on the prescribed initial conditions concerning aerosol characteristics, which also hinge on injection plume dynamics and microphysics.

Up to now, studies into aircraft-based SAI have used simplified plume models, which estimate plume dynamics with considerable uncertainty, and which do not account for effects of the local plume dynamics on the microphysical processes. Here, we work towards reducing this uncertainty by using full computational fluid dynamics representations of plume dynamics within simulations incorporating state-of-the-art microphysics models for the computation of aerosol size distributions in aircraft engine plumes.

In order to anchor our approach in the current literature, we first consider simplified problems with the objective of validating our methodology using existing results. These experiments confirm the attainability of favourable initial aerosol size distributions under roughly the same conditions as shown with other lower-fidelity models. However, our results retain disagreement with respect to previous studies concerning the exact aerosol growth behaviour, highlighting a sensitivity to model choice which may also explain apparent contradictions in those previous studies. 

We then consider a RANS computational fluid dynamic representation of an engine plume. This differs from the simplified plume representation in several ways, including realistic local variations in temperature, vorticity, and eddy viscosity resulting from the inflow determined using a state-of-the-art engine model. This representation is currently being employed in combination with the previously validated microphysical models to simulate realistic aerosol size evolutions for aircraft-based delivery scenarios.

We anticipate our results to (1) provide a higher-confidence foundation on which to base the discussion concerning technological feasibility of SAI-based SRM and (2) constrain the uncertainty range of inputs for model and impact studies, improving reliability of simulations of (desired and undesired) effects of potential SRM scenarios and thereby informing the scientific and public debate.  

How to cite: Tluk, A., de Vries, I., Janssens, M., and Hulshoff, S.: Towards higher fidelity simulations of aerosol growth in aircraft plumes for feasibility and impact assessment of sulfate stratospheric aerosol injection, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7923, https://doi.org/10.5194/egusphere-egu22-7923, 2022.

18:12–18:18
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EGU22-12839
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ECS
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Highlight
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Virtual presentation
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Adrianna Rusek and Miłosz Huber

The Arctic is an area with unique climatic qualities on Earth. Located behind the Arctic Circle, the region is characterized by numerous phenomena such as polar day (in summer) and polar night (in winter), which affect the state of well-being of people living there. The numerous aurorae are examples of magnetic storms whose health effects are most pronounced in this region. Extreme temperatures can be recorded in these zones, especially in winter. At the same time, it is there that the environment shows great sensitivity to changing climatic conditions and human activities. A small increase in temperature can melt permafrost and methane clathrates. At this time, climate change affects the ecosystem of the plant and animal world. At the same time, it is in the Arctic that there are important deposits of energy resources, non-ferrous metals and others. In the Arctic regions there are trade routes connecting the continents (the so-called "Northern Road"). Growing interest in the Arctic contributes to its urbanization. This process is also important in a broader context. Many of the technologies that prove themselves in these harsh conditions will also be applicable in other climate zones. The Arctic is becoming a testing ground for human missions in harsh conditions, a way to survive in an unfavorable climate, and to test pro-environmental technologies. An important advantage of the Arctic is also its great similarity to the climatic conditions of the warmest zones on Mars. However, compared to Mars, planning engineering projects in the Arctic has many advantages. The presence of air at normal pressure, while not preventing the construction of airtight capsules, allows for easier evacuation of personnel in the event of a failure of life support systems.  Working people at various stations in the Arctic can be just as tested for the vulnerability of long periods of being in a small confined space. Nevertheless, there are also numerous localities in the Arctic where people lead relatively normal lives, the best example being northern Scandinavia, which is currently the most urbanized area beyond the Arctic Circle.  Their experience of living in the extreme conditions of the north, the problems of urban development and transportation, environmental protection and many other areas of life in this zone, can be an important source of information for other inhabitants of Earth and Mars.  Issues related to the problems of environmental protection and the fight against pollution in this climate zone will be just as relevant in other zones, where there are many more opportunities to use, for example, renewable energy sources. In the long run, building stable urbanized human settlements in the Arctic will become an example of human activity in the region of Mars and (perhaps) other regions of the Solar System. The authors present numerical data and possible scenarios of sustainable urbanization development in the Arctic based on selected examples of Scandinavian experience. They analyze which of them have universal character and are possible to apply also in other climatic conditions. 

How to cite: Rusek, A. and Huber, M.: "The Arctic - the first step towards the terraformation of Mars. Experiences from northern Europe.", EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12839, https://doi.org/10.5194/egusphere-egu22-12839, 2022.