The term carbon (C) sequestration has not just become a buzzword but is something of a siren’s call to scientific communicators and media outlets. Carbon sequestration is the removal of C from the atmosphere and the storage, for example, in soil. It has the potential to partially compensate for anthropogenic greenhouse gas emissions and is, therefore, an important piece in the global climate change mitigation puzzle. However, the term C sequestration is often used misleadingly and, while likely unintentional, can lead to the perpetuation of biased conclusions and exaggerated expectations about its contribution to climate change mitigation efforts. Soils have considerable potential to take up C but many are also in a state of continuous loss. In such soils, measures to build up soil C may only lead to a reduction in C losses (C loss mitigation) rather than result in real C sequestration and negative emissions. In an examination of 100 recent peer-reviewed papers on topics surrounding soil C, only 4% were found to have used the term C sequestration correctly. Furthermore, 13% of the papers equated C sequestration with C stocks. The review, further, revealed that measures leading to C sequestration will not always result in climate change mitigation when non-CO2 greenhouse gases and leakage are taken into consideration. This paper highlights potential pitfalls when using the term C sequestration incorrectly and calls for accurate usage of this term going forward. Revised and new terms are suggested to distinguish clearly between C sequestration in soils, SOC loss mitigation, negative emissions, climate change mitigation, SOC storage, and SOC accrual to avoid miscommunication among scientists and stakeholder groups in future.
Habitat Type: NA
Not Applicable
Improved knowledge of glacial-to-interglacial global temperature change yields Charney (fast-feedback) equilibrium climate sensitivity 1.2 ± 0.3°C (2σ) per W/m2, which is 4.8°C ± 1.2°C for doubled CO2. Consistent analysis of temperature over the full Cenozoic era—including ‘slow’ feedbacks by ice sheets and trace gases—supports this sensitivity and implies that CO2 was 300–350 ppm in the Pliocene and about 450 ppm at transition to a nearly ice-free planet, exposing unrealistic lethargy of ice sheet models. Equilibrium global warming for today’s GHG amount is 10°C, which is reduced to 8°C by today’s human-made aerosols. Equilibrium warming is not ‘committed’ warming; rapid phaseout of GHG emissions would prevent most equilibrium warming from occurring. However, decline of aerosol emissions since 2010 should increase the 1970–2010 global warming rate of 0.18°C per decade to a post-2010 rate of at least 0.27°C per decade. Thus, under the present geopolitical approach to GHG emissions, global warming will exceed 1.5°C in the 2020s and 2°C before 2050. Impacts on people and nature will accelerate as global warming increases hydrologic (weather) extremes. The enormity of consequences demands a return to Holocene-level global temperature. Required actions include: (1) a global increasing price on GHG emissions accompanied by development of abundant, affordable, dispatchable clean energy, (2) East-West cooperation in a way that accommodates developing world needs, and (3) intervention with Earth’s radiation imbalance to phase down today’s massive human-made ‘geo-transformation’ of Earth’s climate. Current political crises present an opportunity for reset, especially if young people can grasp their situation.
The EU Soil Strategy 2030 aims to increase soil organic carbon (SOC) in agricultural land to enhance soil health and support biodiversity as well as to offset greenhouse gas emissions through soil carbon sequestration. Therefore, the quantification of current SOC stocks and the spatial identification of the main drivers of SOC changes is paramount in the preparation of agricultural policies aimed at enhancing the resilience of agricultural systems in the EU. In this context, changes of SOC stocks (Δ SOCs) for the EU + UK between 2009 and 2018 were estimated by fitting a quantile generalized additive model (qGAM) on data obtained from the revisited points of the Land Use/Land Cover Area Frame Survey (LUCAS) performed in 2009, 2015 and 2018. The analysis of the partial effects derived from the fitted qGAM model shows that land use and land use change observed in the 2009, 2015 and 2018 LUCAS campaigns (i.e. continuous grassland [GGG] or cropland [CCC], conversion grassland to cropland (GGC or GCC) and vice versa [CGG or CCG]) was one of the main drivers of SOC changes. The CCC was the factor that contributed to the lowest negative change on Δ SOC with an estimated partial effect of −0.04 ± 0.01 g C kg−1 year−1, while the GGG the highest positive change with an estimated partial effect of 0.49 ± 0.02 g C kg−1 year−1. This confirms the C sequestration potential of converting cropland to grassland. However, it is important to consider that local soil and environmental conditions may either diminish or enhance the grassland’s positive effect on soil C storage. In the EU + UK, the estimated current (2018) topsoil (0–20 cm) SOC stock in agricultural land below 1000 m a.s.l was 9.3 Gt, with a Δ SOC of −0.75% in the period 2009–2018. The highest estimated SOC losses were concentrated in central-northern countries, while marginal losses were observed in the southeast.
The islands of the Caribbean are particularly susceptible to the effects of climate change due to their low-lying coastal areas and location within the Atlantic basin’s hurricane belt. The UK Overseas Territory of Anguilla is one such island. The predicted increase in the severity of hurricanes and sea-level rise is highly likely to increase the flood risk of already vulnerable island communities. In this study, flood risk and erosion models are used to prioritise opportunity areas for nature-based restoration and to identify those that would have the greatest impact on coastal and in-land flood risk reduction. Two study sites in Anguilla were selected to highlight this ecologically-based modelling approach; Cove Bay and Pond, a degraded sand dune system and brackish pond, and the East End Pond, an Important Bird and Biodiversity Area that floods following heavy rainfall events. At the coastal site, the restoration of mangroves, sand dunes and coral reefs have the potential to provide flood risk reduction up to 500 m inland and protect homes, infrastructure and tourism developments. For the in-land East End Pond, areas of high erosion risk were predominately identified as bare or disturbed land within 1 km of the pond’s basin. Restoration of these areas was identified as having the greatest impact on reducing flood risk. The identification of optimal areas for habitat restoration and modelling the positive impact that habitat restoration can have in reducing flood risk are important tools that can be used to inform the implementation of nature-based solutions and also to advocate and justify such management activities to policy makers and landowners.
Wildfires, exacerbated by climate change and human activities, threaten global ecosystems and societies. Urgent soil restoration strategies are needed to combat the resulting land degradation. Nature-based solutions (NBS) are emerging as sustainable methods to revitalize fire-affected soils and improve ecosystem recovery and resilience. Herein we provide an overview of key NBS strategies, namely microbial soil remediation, biochar application, mulching, seeding, and erosion control. Challenges in scaling and standardizing NBS remain and require robust evaluation frameworks. Further research should quantify the effectiveness of NBS, facilitate its integration into policy and mitigation strategies, and promote public and scientific acceptance. NBS offers a proactive approach to address escalating wildfire risks and harness nature’s resilience to restore fire-affected landscapes and maintain the delicate balance between communities and ecosystems in the face of growing environmental challenges.
Most of the world’s nations (around 130) have committed to reaching net-zero carbon dioxide or greenhouse gas (GHG) emissions by 2050, yet robust policies rarely underpin these ambitions. To investigate whether existing and expected national policies will allow Brazil to meet its net-zero GHG emissions pledge by 2050, we applied a detailed regional integrated assessment modelling approach. This included quantifying the role of nature-based solutions, such as the protection and restoration of ecosystems, and engineered solutions, such as bioenergy with carbon capture and storage. Our results highlight ecosystem protection as the most critical cost-effective climate mitigation measure for Brazil, whereas relying heavily on costly and not-mature-yet engineered solutions will jeopardise Brazil’s chances of achieving its net-zero pledge by mid-century. We show that the full implementation of Brazil’s Forest Code (FC), a key policy for emission reduction in Brazil, would be enough for the country to achieve its short-term climate targets up to 2030. However, it would reduce the gap to net-zero GHG emissions by 38% by 2050. The FC, combined with zero legal deforestation and additional large-scale ecosystem restoration, would reduce this gap by 62% by mid-century, keeping Brazil on a clear path towards net-zero GHG emissions by around 2040. While some level of deployment of negative emissions technologies will be needed for Brazil to achieve and sustain its net-zero pledge, we show that the more mitigation measures from the land-use sector, the less costly engineered solutions from the energy sector will be required. Our analysis underlines the urgent need for Brazil to go beyond existing policies to help fight climate emergency, to align its short- and long-term climate targets, and to build climate resilience while curbing biodiversity loss.
Efforts to avert dangerous climate change by conserving and restoring natural habitats are hampered by concerns over the credibility of methods used to quantify their long-term impacts. Here we develop a flexible framework for estimating the net social benefit of impermanent nature-based interventions that integrates three substantial advances: (1) conceptualizing the permanence of a project’s impact as its additionality over time; (2) risk-averse estimation of the social cost of future reversals of carbon gains; and (3) post-credit monitoring to correct errors in deliberately pessimistic release forecasts. Our framework generates incentives for safeguarding already credited carbon while enabling would-be investors to make like-for-like comparisons of diverse carbon projects. Preliminary analyses suggest nature-derived credits may be competitively priced even after adjusting for impermanence.
The remaining carbon budget (RCB), the net amount of CO2 humans can still emit without exceeding a chosen global warming limit, is often used to evaluate political action against the goals of the Paris Agreement. RCB estimates for 1.5 °C are small, and minor changes in their calculation can therefore result in large relative adjustments. Here we evaluate recent RCB assessments by the IPCC and present more recent data, calculation refinements and robustness checks that increase confidence in them. We conclude that the RCB for a 50% chance of keeping warming to 1.5 °C is around 250 GtCO2 as of January 2023, equal to around six years of current CO2 emissions. For a 50% chance of 2 °C the RCB is around 1,200 GtCO2. Key uncertainties affecting RCB estimates are the contribution of non-CO2 emissions, which depends on socioeconomic projections as much as on geophysical uncertainty, and potential warming after net zero CO2.
Little is currently known about how climate modulates the relationship between plant diversity and soil organic carbon and the mechanisms involved. Yet, this knowledge is of crucial importance in times of climate change and biodiversity loss. Here, we show that plant diversity is positively correlated with soil carbon content and soil carbon-to-nitrogen ratio across 84 grasslands on six continents that span wide climate gradients. The relationships between plant diversity and soil carbon as well as plant diversity and soil organic matter quality (carbon-to-nitrogen ratio) are particularly strong in warm and arid climates. While plant biomass is positively correlated with soil carbon, plant biomass is not significantly correlated with plant diversity. Our results indicate that plant diversity influences soil carbon storage not via the quantity of organic matter (plant biomass) inputs to soil, but through the quality of organic matter. The study implies that ecosystem management that restores plant diversity likely enhances soil carbon sequestration, particularly in warm and arid climates.
Improving the effectiveness of conservation practice requires better use of evidence.
Since 2004, researchers from the Conservation Evidence group (University of Cambridge) have engaged with over 1100 named practitioners, policymakers, funders and other academics from across the world to identify needs and develop a range of principles, tools and resources to embed evidence in decision making. The goal of this engagement (the Conservation Evidence Programme) was to deliver improved conservation practice leading to benefits for nature and society. Together, we developed a theory of change with five key strategies for delivering change, alongside a freely available Evidence Toolkit to support decision makers in achieving that change.
The authors describe the toolkit, a collection of freely available tools and resources developed by the collaborative programme, and how co-design, employing different levels of partner engagement, enabled its development.
Reflecting on our experiences highlighted a number of insights and recommendations, including the need to identify where deep engagement is a necessary condition for success; the importance of collective agreement of the roles of different partners; the need to consider how to facilitate uptake of new tools or practices, particularly where that requires changes to organisational practices or culture; and the importance of establishing processes/channels for ongoing engagement with stakeholders, with a willingness to be flexible and open to incorporating new suggestions and perspectives as needed.
The Conservation Evidence Programme has enabled practitioners, funders and policymakers to become part of a network of forward-thinking organisations that is working collaboratively to help drive more effective conservation practice through improved evidence use.
Finite land is under pressure to provide food, timber, human infrastructure, climate change mitigation, and wildlife habitat. Given the inherent trade-offs associated with land-use choices, there is a need to assess how alternative land-use trajectories will impact the delivery of these benefits. Here, we develop nine exploratory, climate change mitigation-driven land-use scenarios for the UK. The scenario that maximized deployment of nature-based solutions reduced greenhouse gas (CO2e) emissions from the land sector by >100% by 2050 but resulted in a 21% decline in food production.
All mitigation scenarios delivered aggregate increases in habitat availability for 109 bird species (including 61 species of conservation concern), although farmland-associated species lost habitat. Our study reiterates the potential of nature-based solutions to address global climate and biodiversity challenges but also highlights risks to farmland wildlife and the importance of food system reform to mitigate potential reductions in primary food production.
Climate extremes are on the rise. Impacts of extreme climate and weather events on ecosystem services and ultimately human well-being can be partially attenuated by the organismic, structural, and functional diversity of the affected land surface. However, the ongoing transformation of terrestrial ecosystems through intensified exploitation and management may put this buffering capacity at risk. Here, we summarise the evidence that reductions in biodiversity can destabilise the functioning of ecosystems facing climate extremes. We then explore if impaired ecosystem functioning could, in turn, exacerbate climate extremes. We argue that only a comprehensive approach, incorporating both ecological and hydrometeorological perspectives, enables to understand and predict the entire feedback system between altered biodiversity and climate extremes. This ambition, however, requires a reformulation of current research priorities to emphasise the bidirectional effects that link ecology and atmospheric processes.
Land-based carbon sequestration projects, such as tree planting, are a prominent strategy to offset carbon emissions. However, we risk reducing natural ecosystems to one metric – carbon. Emphasis on restoring ecosystems to balance ecosystem services, biodiversity conservation, and carbon sequestration is a more appropriate strategy to protect their functioning.
The rate and extent of global biodiversity change is surpassing our ability to measure, monitor and forecast trends. We propose an interconnected worldwide system of observation networks — a global biodiversity observing system (GBiOS) — to coordinate monitoring worldwide and inform action to reach international biodiversity targets.
This planetary boundaries framework update finds that six of the nine boundaries are transgressed, suggesting that Earth is now well outside of the safe operating space for humanity. Ocean acidification is close to being breached, while aerosol loading regionally exceeds the boundary. Stratospheric ozone levels have slightly recovered. The transgression level has increased for all boundaries earlier identified as overstepped. As primary production drives Earth system biosphere functions, human appropriation of net primary production is proposed as a control variable for functional biosphere integrity. This boundary is also transgressed. Earth system modeling of different levels of the transgression of the climate and land system change boundaries illustrates that these anthropogenic impacts on Earth system must be considered in a systemic context.
In light of the critical role of tropical forests in stabilizing the global climate system through both carbon and noncarbon pathways, maintaining and increasing incentives for large-scale forest conservation is an essential component of climate action. Demand for carbon credits, one of the most promising mechanisms for funding large-scale forest conservation, has grown rapidly in recent years, with the voluntary carbon market seeing transactions worth almost US$2 billion in 2021. In 2022, however, the volume of transactions leveled off, at least in part due to concerns about reputational risk from corporate buyers afraid of greenwashing accusations.
Twenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures.
Nature-Based Solutions can be considered one of the best answers to the various consequences and problems caused by climate change, poor urbanisation and population growth. They are used not only as measures for the protection, sustainable management and restoration of natural and modified ecosystems but also as measures to mitigate certain natural disasters such as erosion, flooding, drought, storm surge and landslide. The benefit is for both biodiversity and human well-being. This paper reviews articles about optimising the selection and placement of Nature-Based Solutions. It presents several Operations Research approaches used in the context of climate adaptation. The analysis provided in this paper focuses on various case studies, state-of-the-art on Nature-Based Solutions, Operations Research algorithms, dissertations, and other papers dealing with infrastructure placement approaches in the context of climate adaptation.
Adaptation is increasing across all sectors globally. Yet, the effectiveness of adaptation is inadequate, and examples of maladaptation are increasing. To reduce the risk of maladaptation, we propose the framework, Navigating the Adaptation–Maladaptation continuum (NAM). This framework is composed of six criteria relating to outcomes of adaptation for ecosystems, the climate (greenhouse gases emissions) and social systems (transformational potential) as well as equity-related outcomes for low-income populations, women/girls and marginalized ethnic groups. We apply the NAM framework to a set of representative adaptation options showing that considerable variation exists in the potential for adaptation or the risk of maladaptation. We suggest that decision-makers assess adaptation interventions against the NAM framework criteria and prioritize responses that reduce the risk of maladaptation.
Twenty-five years since foundational publications on valuing ecosystem services for human well-being1,2, addressing the global biodiversity crisis3 still implies confronting barriers to incorporating nature’s diverse values into decision-making. These barriers include powerful interests supported by current norms and legal rules such as property rights, which determine whose values and which values of nature are acted on. A better understanding of how and why nature is (under)valued is more urgent than ever4. Notwithstanding agreements to incorporate nature’s values into actions, including the Kunming-Montreal Global Biodiversity Framework (GBF)5 and the UN Sustainable Development Goals6, predominant environmental and development policies still prioritize a subset of values, particularly those linked to markets, and ignore other ways people relate to and benefit from nature7. Arguably, a ‘values crisis’ underpins the intertwined crises of biodiversity loss and climate change8, pandemic emergence9 and socio-environmental injustices10. On the basis of more than 50,000 scientific publications, policy documents and Indigenous and local knowledge sources, the Intergovernmental Platform on Biodiversity and Ecosystem Services (IPBES) assessed knowledge on nature’s diverse values and valuation methods to gain insights into their role in policymaking and fuller integration into decisions7,11. Applying this evidence, combinations of values-centred approaches are proposed to improve valuation and address barriers to uptake, ultimately leveraging transformative changes towards more just (that is, fair treatment of people and nature, including inter- and intragenerational equity) and sustainable futures.
There is potential for nature-based solutions (NbS) to contribute to climate-resilient development (CRD) due to their integrated approach to mitigation, adaptation, and sustainable development. However, despite alignment between NbS and CRD’s objectives, realization of this potential is not guaranteed. A CRD pathways (CRDP) approach helps to analyze the complexities of the relationship between CRD and NbS, and a climate justice lens enables the identification of the multiple ways that NbS can support or undermine CRD by foregrounding the politics inherent in deciding between NbS trade-offs. We use stylized vignettes of potential NbS to examine how the dimensions of climate justice reveal the potential of NbS to contribute to CRDP. We consider tensions in NbS projects between local and global climate objectives, and the potential for NbS framing to reinforce inequalities or unsustainable practices. Ultimately, we present a framework that combines climate justice and CRDP in an analytical tool for understanding the potential for a NbS to support CRD in specific places.
The Cerrado biome in Brazil is the most biodiverse savannah in the world1 and has a key role in stabilizing both the local and the global climate, storing carbon and providing fresh water to the country2. Yet, the Cerrado has little protection and is being converted for agriculture at an alarming rate. Recently released official data reveal that, in 2022, deforestation in the biome rose for the third consecutive year3. The area cleared was 25% higher than the previous year, reaching 10,689 km² (ref. 3), rivalling the rates of deforestation in the Brazilian Amazon (12,479 km²), despite the Cerrado being only half the size3. Almost three-quarters of that conversion took place in the MATOPIBA agricultural frontier, where nearly 25% of Cerrado’s soybean harvest is planted4. The current high rates of conversion even jeopardize the future of agricultural production in the Cerrado. The loss of the Cerrado has contributed to extreme climate events over the past decade5, which increased surface-sensible heat flux, reduced evapotranspiration and crop yields and threatened the feasibility of multi-cropping systems6, as well as exacerbated land concentration and farmers’ indebtedness.
The review aims to present the effects of climate change on biodiversity and its remedial measures using Nature based solution (Nbs). At least 40% of the world’s economy, and 80% of the economy of less industrialized nations, is derived directly from biological resources as a function of ecosystem service. Climate change is a key driver for mass extinction, latitudinal and altitudinal shifts of species location, change in species richness and composition, change in phenology, decline in ecosystem services and outbreak of plant and animal disease. The most important notable drivers behind the current loss of biodiversity are habitat modification, overexploitation, climate change, invasive alien species, and chains of extinction. Loss in biodiversity has been attributed primarily to changes in the intensity by which the land and sea are used (34% contribution to losses over the past century) and direct exploitation of species (23%), followed by climate change and pollution (14% each). The impact of climate change is projected to surpass other threats during the twenty-first century both through direct effects and intensifying interactions with other drivers. Under a global warming scenario of 1.5 °C warming, 6% of insects, 8% of plants and 4% of vertebrates are projected to lose over half of their climatically determined geographic range. For global warming of 2 °C, the comparable fractions are 18% of insects, 16% of plants and 8% of vertebrates. Future warming of 3.2 °C above preindustrial levels is projected to lead to loss of more than half of the historical geographic range in 49% of insects, 44% of plants, and 26% of vertebrates. Nature based solutions such as protection of intact ecosystems, managing working lands and restoring native cover are some of the important measures for climate change mitigation and biodiversity protection, although it will be difficult to achieve without the reduction fossil fuel emissions.
This study examines how residents of nature-based tourism destinations become supportive of sustainable tourism development based on an integrated theoretical framework that combines social exchange theory and bottom-up spillover theory. A survey of 364 residents in Jechon City, South Korea measured their perceptions of tourism impacts using a neutral-phrase questionnaire (non-forced approach). Results from structural equation modeling showed that residents perceive tourism as having a significant positive impact on material and non-material aspects of their lives, which leads to overall quality of life and support for sustainable tourism development. The integration of social exchange theory and bottom-up spillover theory proved to be a useful framework in predicting residents’ support for sustainable tourism development. The study results suggest that to foster local residents’ support for sustainable tourism development, planners should consider the impact of tourism on material and non-material aspects of residents’ lives, emphasize environmental considerations, and focus on long-term benefits.
The process of urbanization can alter the local climate to the point that it threatens citizens’ well-being by creating heat-related hazards. The construction of Blue-Green Infrastructure (BGI) can improve the regulation of surface energy exchange processes and address this problem. However, the time needed for a BGI to deliver a stable cooling performance, referred to here as the Cooling Establishment Time (CET), is poorly understood and quantified in the literature and dependent on environmental, design and maintenance factors. Here, we analyze the feasibility of using satellite data to derive the CET for different BGIs across the city of Zurich, Switzerland. Results showed that remote sensing can quantify the land surface temperature impact of BGIs and assist in estimating their CET. BGI with trees or climbing plants required a longer CET (seven to ten years) before any notable shift in surface temperatures were visible, while grasses or artificial irrigated systems led to shorter CETs (one to three years). These results allow us to better account for BGI cooling establishment when planning for areas that need urgent action under warming climates. This work supports evidence-based urban greenery planning and design towards cooling our increasingly warming cities in a timely manner.