As various political initiatives have set goals to reach net-zero emissions by
the mid-21st century, forests will play an important role as a carbon sink for sequestering
unavoidable emissions. Forest management can take two approaches
by either decreasing harvest and enlarging the forest carbon stock or increasing
harvest to increase carbon uptake of the remaining forest stock and create harvested
wood products (HWPs). Currently, these two management options seem
at odds with seemingly conflicting policy directives being written. We used the
BEKLIFUH model to assess six management scenarios based on carbon offset
potential taking into consideration forest carbon, HWPs and the material and
energetic substitution effects. The results show that while conservation leads
to a higher above-ground carbon pool, including HWPs, material and energetic
substitution leads to more overall carbon offsets for management scenarios with
more timber harvesting. With compromise being possible by selectively conserving
old growth forests with a high biodiversity value. In conclusion, if the
forest sector decouples GHG reporting from forest management and includes
all the secondary effects of timber harvest, this new approach can lead to a
different cost–benefit analysis for the choice between harvest vs. conservation.
This could result in a paradigm shift to a future where biodiversity and carbon
neutrality can coexist.

How to cite: Martes, L. and Köhl, M.: Improving the Contribution of Forests to CarbonNeutrality under Different Policies—A Case Study fromthe Hamburg Metropolitan Area, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3324, https://doi.org/10.5194/egusphere-egu23-3324, 2023.

Farm Africa is an international NGO working with smallholder farmers in eastern Africa to promote sustainable agriculture, improved market access, and holistic natural resource management.

Smallholder farmers and pastoralists rely on the natural environment for their livelihoods, and they are also the custodians of significant global goods – the habitats and biospheres that exist as soils, rangelands and forests. How they manage those natural resources has a significant impact on the carbon cycle.

Food production in the region is increasingly under pressure as a result of climate change, conflict, population growth and poor agriculture and land management practices. As natural habitats are exhausted, through soil health depletion, drought, deforestation, or overgrazing, so the ability of those landscapes to sequester carbon is reduced.

Integrated Landscape Management (ILM) provides a powerful nature-based solution to habitat restoration as well as improving food security, combining habitat protection with a multi-stakeholder approach to resource governance, benefit sharing and sustainable livelihoods. This has a significant impact on the carbon cycle, either through the prevention of carbon emissions from deforestation, or through the restoration of landscapes to the extent that soil health and biomass increase carbon sequestration, for example through agroforestry, rangeland restoration, and regenerative agriculture.

ILM works through a set of complementary incentives: diversified livelihoods help communities make more income through the sustainable use of the natural environment than they do from denuding it.  For example, farmers’ yields increase after adopting climate-smart agriculture practices or forest dwellers are able to harvest and sell forest-friendly produce such as wild coffee. Participatory governance arrangements for landscapes give communities a strong stake in the management of the natural resources that they rely on; and the transparent sharing of income from the sale of carbon credits further promotes the protection of the environment.

Farm Africa’s REDD+ project in the Bale Eco-region of Oromia, Ethiopia is a powerful example of nature based carbon management. Funded by the Norwegian Government, the project has resulted in more than 25,000 hectares of forest being saved, and emissions being reduced by 10.5 million tonnes of CO2e. Livelihoods have diversified away from agricultural expansion and into non-timber forest products, in particular high value forest coffee. A pioneering model of participatory forest management has seen responsibility for forest protection shared between local government and 64 forest cooperatives, who have also shared the income from the sale of carbon credits on the voluntary carbon market.

Average annual household incomes of the forest dependent communities that we worked with rose by 143% from 17,000 Ethiopia Birr in 2016 to 43,000 Birr in 2021 (excluding income from carbon sales). This provides a strong incentive for the communities to continue to protect the forest, and to keep carbon locked in the biosphere.

The evidence shows that ILM can support carbon management at scale as a nature based solution, and that if properly agreed, structured and transparently handled with local communities, carbon credits can be an important part of that solution..

How to cite: Collison, D.: Carbon Management through Participatory Forest Governance in the Bale Eco-region, Oromia, Ethiopia, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-3161, https://doi.org/10.5194/egusphere-egu23-3161, 2023.

Conversion of land to short rotation forestry (fast growing, densely planted trees, harvested within 15 years) has increased in recent years.  The wood produced is primarily used in short lived products (e.g. paper) or as biomass for renewable energy production, quickly returning carbon to the atmosphere. 

We ask, how much potential is there to sequester carbon via short rotation forestry and how does it differ between species when soil type and meteorological conditions are the same?

We present preliminary results from a species field trial nearing maturity (planted in 2010), comparing soil carbon stocks (pre-planting to the present day); woody biomass; total and heterotrophic below-ground respiration; soil methane fluxes and leaf area index assessments between six commonly used short rotation forestry species (silver birch, common alder, sycamore, sweet chestnut, aspen and red alder). 

How to cite: Gatis, N., Galstaun, L., Luscombe, D., Vanguelova, E., Hill, T., Xenakis, G., Wilkinson, M., Heard, M., Anderson, K., Morrison, J., and Brazier, R.: How does the potential to sequester carbon via short rotation forestry vary with species?, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5407, https://doi.org/10.5194/egusphere-egu23-5407, 2023.

In recent decades, anthropogenic disturbance and rising climate change exposed global lakes, in particular shallow lakes,  to an increased risk of eutrophication. Thus received global attention due to their high greenhouse gas (GHG) emissions contributing to global warming. The role of the lake trophic state index (TSI) and water quality parameters such as chlorophyll-a (Chl-a), pH, total organic carbon (TOC), and total phosphorus (TP) on GHG emissions are still poorly estimated and a hot topic of global discussion to understand the key sources and drivers of GHG emissions. In this study, GHG and lake eutrophication datasets of 146 lakes in China have been collected from the scientific literature and analyzed statistically to determine the influence of lake eutrophication on GHG emissions. The statistical analysis reveals that Chl-a (R² > 0.90) and TOC (R² > 0.65) are the key factors of eutrophication and dominate carbon intensity dynamics in the Chinese lakes. Our finding further suggests that CH₄ contributes largely to regional carbon budgets compared to CO₂ and N₂O. Proactive management of lake catchment not only reduces the potential GHG emissions but also helps in lake restorations.

How to cite: Kumar, A.: Impact of water quality drivers and lake eutrophication on greenhouse gas emission rate: A critical analysis, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1986, https://doi.org/10.5194/egusphere-egu23-1986, 2023.

Recently, the action on climate crisis response was emphasized with spread of carbon neutrality from the international community, and the role of forests which is carbon sink was further accentuated. Forest is an important role to respond climate change. Therefore, it could be utilized for the strategy for achieving carbon neutrality. Forest in South Korea account for approximately 63 percent (6,286,438 ha) of land area. In this study, KO–G–Dynamics (Korean dynamic stand growh) model was used for estimating carbon sink with forest management considering watershed, which could help decision making through not fragmented but consistent forest management. Korean reach file (KRF) and forest functions (production forest, disaster prevention for forest etc.) classification map were used for considering watershed and each function. Especially, forest having different functions is applied to different methods of forest management. In addition, in the study, the data including species and age etc., which are representing the forest characteristics, based on 1 ha (100 m x 100m) resolution were used. Compared with a proceeding studies and national statistics, more accurate stem volumes (1,058 million m³ in 2020) and biomass (1,245 million ton in 2020) were estimated. In addition, the study is significant in the sense that diverse management methods in accordance with forest functions and watershed are considered. Furthermore, accurate modeling is possible through understanding of inhomogeneity on forest stands and forest in island area. It could help decision making of forest policy

How to cite: Ko, Y., Kim, M., Hong, M., and Lee, W.: Studying forest management and carbon absorption considering watershed in South Korea, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6478, https://doi.org/10.5194/egusphere-egu23-6478, 2023.

ECOPIA^TM (Earth Climate Optimisation Productivity Island Array) is a global solution to the anthropogenic climate change problem, without the risks of engineering the environment itself. Led by Ecopia Marine Ltd, and MyOcean Resources Ltd., ECOPIA^TM empowers the natural primary production capacity of the oceans solely through the provision of light. The programme provides a global Nature Based Carbon Management Solution (NBCMS) removing the excess atmospheric CO₂, de-acidifying the ocean’s waters, creating new sustainable fisheries, and importantly allowing the economies of the world to continue to grow and prosper, https://www.youtube.com/watch?app=desktop&v=O7hbQVbpojI.

ECOPIA^TM’s global Nature Based Carbon Management Solution (NBCMS) effects the natural capture and storage of carbon, enabling the control and regulation of CO₂ levels in the atmosphere via natural mechanisms. Many nature based solutions have significant uncertainties that largely come about from the practise of engineering the composition of the environment. ECOPIA^TM takes a different approach, that of channelling light down to the depths where there are plenty of naturally determined nutrients and seed population. Through simply providing light and nothing more, ECOPIA^TM provides no mechanism for a preferential pressure on the naturally determined biodiversity of the light cultured ecosystem.

The ECOPINs (Earth Climate Optimisation Productivity Island Nodes) that make up ECOPIA^TM will be located in the great oligotrophic gyres of the world’s oceans. These otherwise minimally productive gyres are growing at a rate of 80 million hectares (800,000 km²) per year, at the cost of productive ocean areas. Taking the, perhaps pessimistic, view that the world as a whole can only achieve a static anthropogenic fossil fuels usage by the year 2030, then around 100 ECOPINs will be required; this is derived from the approximately 100 Megatonnes uptake of carbon as atmospheric CO₂ to be achieved per ECOPIN per year, or 10 Gigatonnes per year by ECOPIA^TM in total.

As a modular, scalable solution made up of ECOPINs, which themselves are modular, scalable, floating structures, each ECOPIN will take up approximately 2,000 km² of ocean surface, just 0.25% of the otherwise annual rate of decrease of productive ocean area. Of course as a scalable system, if greater reductions in fossil fuels usage can be achieved then the size of ECOPIA^TM reduces approximately linearly.

Having worked out how to supercharge the combustion side of the Earth’s carbon cycle through the incredible ingenuity of the industrial revolution it is not surprising to find that there are NBCMSs for supercharging the photosynthetic side of this natural cycle and rebalancing the system. Ecopia Marine and MyOcean Resources have a solution to the global problem of excess anthropogenic carbon; the Earth’s oceans are indeed the true lungs of our world and we are committed to engaging this ocean-based solution to let the oceans save our planet. 

How to cite: Allen, J., Fitzgerald, C., and Franks, L.: Re-balancing the Earth’s Natural Carbon Cycle; Greening the Deserts of the Oceans through Tele-illumination, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8864, https://doi.org/10.5194/egusphere-egu23-8864, 2023.

Forest ecosystems provide many essential services such as climate regulation and carbon storage, which are important for many industries and for global Earth system health. However, forest ecosystems are endangered by ongoing resource exploitation and climate and land cover changes which could lead to the destruction of large quantities of forest carbon stocks and stand inventory. Nature-based climate solutions are gaining traction in recent years, particularly forest thinning techniques like variable retention harvesting (VRH) which promotes forest growth, biodiversity, and ecosystem function. Still, they require an intensive assessment of their contribution to forest structure and enhanced carbon dioxide (CO₂) sequestration, but traditional inventory-based forest monitoring practices are time-, cost-, and labour-intensive and impractical at a national scale. In this study, we implement a comprehensive methodology of forest monitoring that uses a combination of field measurements, digital hemispherical photography, spectroscopic analysis, and unmanned aerial vehicle (UAV)-derived data to derive canopy structure, light environment, and soil biogeochemistry. We evaluated the impact of four different VRH treatments on the leaf area index (LAI), canopy openness, photosynthetically active radiation (PAR) absorbance, biomass, and soil carbon and nitrogen content of an 84-year-old red pine (Pinus resinosa) plantation forest in Southern Ontario, Canada. The VRH treatments included 33% dispersed crown retention (33D), 33% aggregated crown retention (33A), 55% dispersed crown retention (55D), and 55% aggregated crown retention (55A). Our findings show that the VRH treatments were major controls or drivers of seasonal variation in LAI, canopy openness, PAR absorbance, biomass, and soil carbon and nitrogen content. Our study suggests that the dispersed crown retention of 55% basal area is the ideal forest thinning technique to enhance CO₂ sequestration and preserve forest structure and light environment. This study provides insight into the interactions between forest ecosystem dynamics and silvicultural interventions, which is indispensable for improving our understanding of nature-based climate solutions. It will also help outline the framework for monitoring forest structure and CO₂ sequestration on large spatiotemporal scales.

How to cite: So, K., Rogers, C. A., Sharma, T., Badzioch, R., and Gonsamo, A.: Role of forest thinning techniques towards nature-based climate solutions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10106, https://doi.org/10.5194/egusphere-egu23-10106, 2023.

Greenlight Bio Oil LLC’s patent-pending process grows and harvests locally sourced marine microalgae and cyanobacteria offshore, processes them into biofuel and converts the remaining matter into fertilizer to grow more microalgae. The process absorbs as much CO2 in fuel production as is created when the fuel is used: true carbon neutrality. 

Current research into growing algae is concentrated in developing land-based systems: either photobioreactors where algae are grown indoors in closed systems often under artificial light, or in purpose-built ponds. These have several disadvantages for the mass industrialization needed to have a significant impact on climate change. Although the productivity of algae farming is much greater than arable farming, tens of millions of acres of land and billions of tons of water would be required to generate sufficient energy to replace fossil fuels at their current rate of use. Rather than the difficult and expensive process of replicating the marine environment on land, Greenlight Bio Oil LLC proposes growing marine algae in their natural environment using an installation we call a Bioil Rig^TM. 

The Bioil Rig^TM is composed of an interconnected array of modular enclosures that float below the ocean surface. Some of these enclosures have impermeable walls. These are stocked with local algae and bacteria and kept in a nutrient-rich environment to promote rapid growth. Once sufficent biomass concentration is reached, the algae are transferred to other enclosures that have permeable walls to allow seawater to pass through. As the local sea water is rich in dissolved inorganic carbon (DIC), but poor in micronutrients, autotrophic growth becomes focused on producing lipids and carbohydrates with little reproduction. The algae are harvested when their rate of biomass growth tapers off and transferred to a processing platform. 

The algae are processed to separate out their lipids, in a similar process to vegetable oil production. Other useful products may be separated, and the remaining bioavailable material is returned to the impermeable enclosures to promote further growth. System losses of nitrogen-containing chemicals should be replaced by growing nitrogen-fixing bacteria. But other micronutrients such as phosphorous may have to be imported. So, limiting system losses is essential to economic production. However, as all organic materials will remain bioavailable, losses will promote local biomass growth and eventual carbon sequestration. Positioning permeable enclosures at the extremities will encourage reuptake of system losses. 

Given the much greater consistency of the growing environment of the equatorial seas, productivity should be higher than the land-based ponds north of the Tropics that have currently been trialed. However, assuming this as a worst case, 6 billion enclosures covering 240,000 sq miles (620 000km²) would match current fossil oil extraction of 100 million barrels per day. The marginal cost of biofuel is expected to be of order $30 per barrel, making this a practical, short-term solution to decarbonize 26% of GHG emissions, without rebuilding the global energy infrastructure in which the World has invested trillions of dollars. 

How to cite: Brown, D.: The Bioil RigTM: growing carbon neutral fuels to replace all fossil oil extraction, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10804, https://doi.org/10.5194/egusphere-egu23-10804, 2023.

Coastal cities are facing unexpected repercussions due to climate change. Thus, it is urgent and necessary to introduce nature-based solutions to enhance ecosystem services. However, since most coastal cities are highly urbanized and fully densified, it is difficult to find spaces to apply nature-based solutions. In this context, this study focused on vacant lands as alternative spaces, abandoned and remnant areas with high biodiversity and ecological values. This study aimed to evaluate how adopting nature-based solutions in vacant lands might improve ecosystem services including carbon storage, flood control, air quality control, and building energy saving. This study selected Seoguipo-si of Jeju-do as a study site because this city is considered as one of the cities most vulnerable to the effects of climate change in South Korea. First, this study investigated the social-ecological characteristics of vacant lands, such as geographical data, specification of trees and shrubs, vegetation composition, and land-use patterns. Then, this study determined that the study area had six types of vacant lands including (1) unmanaged vegetation with no grass, (2) single tree with grass cover, (3) street trees, (4) multi-layered vegetation, (5) single-layered vegetation, and (6) mini-lot vegetation. Second, this study assessed and simulated the improvement of ecosystem services according to types of vacant lands, planting strategies, and budget levels of nature-based solutions. The results show that prioritizing the introduction of multi-layered vegetation in areas vulnerable to climate change helped improve ecosystem services. Also, it was found that the higher the budget, the better the ecosystem services in vacant lands of the study area. Based on the results, this study suggested specific restoration strategies for applying nature-based solutions to vacant lands in the coastal city. The findings of this study can contribute to a deeper understanding of the novel role that vacant lands play in building coastal resilience. Also, the evidence-based design for adopting nature-based solutions conducted in this study may provide the basis for climate adaptive urban planning with limited budget and spaces.

Funding: This research was suported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2022R1A6A3A01087632).

How to cite: Kim, M. and Chon, J.: Nature-based Solutions for improving ecosystem services from vacant lands in a coastal city, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-11309, https://doi.org/10.5194/egusphere-egu23-11309, 2023.

Nature-based solutions (Nbs) are seen as an effective way to mitigate climate change and stabilize the climate of the earth. Here, we report ground measurements of a newly established forest site on the campus of IIT Palakkad, Kerala India (lat = 10.809, lon =76.746). The site (approximately 1600 meter² ) was previously dominated by fountain grass, which is locally considered to be an invasive species. After land preparation, a new forest utilizing approximately 20 native species of trees was planted following Miyawaki's methodology. Direct measurements of tree diameter at the breast height (tbh) were made to estimate total standing biomass using species specific allometric equations. The standing biomass after two years is estimated to be 3261 kg (5967 kg CO₂) over the entire forest area. The total carbon sequestered during the first two years of this forest’s life is sufficient to neutralize carbon emission by a gasoline car driven for a distance of 48909  km or carbon emission by a car running on 100E fuel over a distance of 349355 km. Our work demonstrates that the carbon sequestration rate (18 tons CO₂ ha^-1 yr^-1) by the forest established using the Miyawaki method at our study site is comparable to some of the most productive forests reported in the available literature. Further, our analysis demonstrates that NbS can be made more efficient if spatial land use planning can be optimized to make room for sustainable biomass production for energy and conservation purposes.

How to cite: Jaiswal, D., Surendran, S., Lopus, M., Kushwaha, A., K Chandrabose, A., Geveena, A., Shaji P, S., Nair, S., and Sreejith, K. A.: Fast Growing Forests (FGF) to offset Greenhouse Gas (GHG) Emissions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-14054, https://doi.org/10.5194/egusphere-egu23-14054, 2023.

Peri-urban plantations - artificial forests located near urban areas - in the Mediterranean context are often degraded due to the combined effect of human inactivity and climate changes. Degraded peri-urban forests provide fewer ecosystem services and have reduced biodiversity compared to natural and semi-natural forests.

Silvicultural practices – such as thinning, pruning, weeding, planting – can increase the amount of carbon stored in trees and forests. Thinning can also create more growing space for new trees, resulting in higher carbon sequestration. Additionally, thinning in forests can increase tree mechanical stability and reduce the forest fires risk and, consequently, the related large amounts of carbon released into the atmosphere.

While the main trend of the process is well known, the magnitude can vary significantly according to the climate, the starting condition of the stand, and the natural and human disturbances. All these causes can impact the payback time of carbon stocks. Payback time refers to the time span for the carbon recovering by remaining trees after thinning intervention.

In this study case, we report the results of a silvicultural trial in a mixed peri-urban degraded plantation after 6 years from thinning. Three different silvicultural treatments were compared: a) moderate thinning from below (-20% of current biomass) representing the typical silvicultural treatment of Italian Apennine and considered the traditional scenario; b) intense selective thinning (-30% of current biomass) representing the innovative scenario and c) no management considered the business-as-usual scenario). We also projected the growth to estimate the payback time in recovering harvested carbon stock.

The results show that the more intense thinning has a positive impact on carbon sequestration in the following years, confirming literature results. Besides, the estimated payback time was a) of about 7 years for recovering (in both thinning approaches) the harvested volume; b) of about 8 years for innovative thinning overcoming traditional one; c) of about 12 years for innovative thinning overcoming the control option; d) of about 17 years for traditional thinning overcoming the control option. Finally, we also observed a significant tree mechanical stability increasing from no management option to both thinning options after 2 years. After 6 years, we observed an additional increase of stability for the stands treated with the innovative thinning, while for stands treated with traditional thinning the difference with business as usual reduced until losing its significance.

How to cite: Chiavetta, U., Mazza, G., Paletto, A., De Meo, I., Di Carlo, M., Lagomarsino, A., and Cantiani, P.: How different thinning can improve carbon sequestration, carbon stock and mechanical stability in peri-urban mixed forest stands: a study case in Mediterranean environment., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17228, https://doi.org/10.5194/egusphere-egu23-17228, 2023.

Carbon dioxide in the atmosphere causes global warming as a greenhouse gas. Therefore, countries around the world are considering underground storage to reduce carbon dioxide. Carbon dioxide underground storage means injection before waste gas filed, oil field, deep saline aquifer and so on. The temperature and pressure conditions of carbon dioxide for underground storage are supercritical, and a reduction in injection efficiency is expected due to high capillary pressure during injection. In this study, considering the high capillary pressure, utilizing anionic surfactants (SDS, SDBS). Thus, the enhancement of carbon dioxide efficiency with surfactant type and concentration was evaluated. In addition, quantitative injection characteristics according to the injection rate of carbon dioxide were analyzed using a micro model.

Experimental results look like follow. Surfactant exhibits higher injection efficiency than water at low carbon dioxide injection rates, and the difference in injection efficiency between water and surfactant decreases as the injection rate increases. However, the differences between the types of surfactants (SDS, SDBS) and concentrations used in this study are relatively modest.

To solve the experimental technology limitations in field use, the pore network model is used. The pore network model has the advantage of effective prediction of carbon dioxide injection efficiency in the future. To validate the Pore network model, constructed network is like the micromodel. As a result, the analysis derived the same tendency as the experiment. In the future expected, the pore network model developed in this study will be able to predict carbon dioxide injection.

How to cite: Jung, J., Gang, S., and Ryou, J.-E.: Increase of injection efficiency in geological CO2 sequestration using SDS and SDBS, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1974, https://doi.org/10.5194/egusphere-egu23-1974, 2023.