The UN Decade on Ecosystem Restoration offers immense potential to return hundreds of millions of hectares of degraded tropical landscapes to functioning ecosystems. Well-designed restoration can tackle multiple Sustainable Development Goals, driving synergistic benefits for biodiversity, ecosystem services, agricultural and timber production, and local livelihoods at large spatial scales. To deliver on this potential, restoration efforts must recognise and reduce trade-offs among objectives, and minimize competition with food production and conservation of native ecosystems. Restoration initiatives also need to confront core environmental challenges of climate change and inappropriate planting in savanna biomes, be robustly funded over the long term, and address issues of poor governance, inadequate land tenure, and socio-cultural disparities in benefits and costs. Tackling these issues using the landscape approach is vital to realising the potential for restoration to break the cycle of land degradation and poverty, and deliver on its core environmental and social promises.
Archives: Publications
- There is an increasing recognition that, although the climate change and biodiversity crises are fundamentally connected, they have been primarily addressed independently and a more integrated global approach is essential to tackle these two global challenges.
Nature-based Solutions (NbS) are hailed as a pathway for promoting synergies between the climate change and biodiversity agendas. There are, however, uncertainties and difficulties associated with the implementation of NbS, while the evidence regarding their benefits for biodiversity remains limited. - We identify five key research areas where incomplete or poor information hinders the development of integrated biodiversity and climate solutions. These relate to refining our understanding of how climate change mitigation and adaptation approaches benefit biodiversity conservation; enhancing our ability to track and predict ecosystems on the move and/or facing collapse; improving our capacity to predict the impacts of climate change on the effectiveness of NbS; developing solutions that match the temporal, spatial and functional scale of the challenges; and developing a comprehensive and practical framework for assessing, and mitigating against, the risks posed by the implementation of NbS.
- Policy implications. The Conference of the Parties (COP) for the United Nations Framework Convention on Climate Change (COP26) and the Convention on Biological Diversity (COP15) present a clear policy window for developing coherent policy frameworks that align targets across the nexus of biodiversity and climate change. This window should (a) address the substantial and chronic underfunding of global biodiversity conservation, (b) remove financial incentives that negatively impact biodiversity and/or climate change, (c) develop higher levels of integration between the biodiversity and climate change agendas, (d) agree on a monitoring framework that enables the standardised quantification and comparison of biodiversity gains associated with NbS across ecosystems and over time and (e) rethink environmental legislation to better support biodiversity conservation in times of rapid climatic change.
Nature-based solutions (NBS) enable the ecosystem service benefits associated with natural landscapes to be embedded into the built environment, simultaneously providing environmental, social, and economic benefits. This represents a mechanism for renaturing cities that can address many of the interrelated challenges associated with urbanisation and climate change. If NBS can be delivered effectively on citywide scales, it presents an opportunity for the development of sustainable, resilient, and liveable cities. Examples of innovation in relation to planning and delivering NBS are emerging globally. However, the stewardship plan, an essential element of NBS that typically underpins the long-term success of these high-profile initiatives, is often overlooked or under-planned. Careful consideration of the technical, financing, and governance aspects of NBS stewardship can be critical to determining whether an NBS is able to deliver the multifunctional benefits for which it was designed, adapt to changing needs and environmental conditions, and avoid becoming a liability to those communities it was designed to benefit. Here we present a series of case studies demonstrating how innovation in NBS stewardship can secure and maximise the long-term success of NBS and avoid the legacy of neglected or poorly managed green wash.
Nature-based solutions (NBS) include a wide spectrum of situations: natural and seminatural green spaces, urban forests, designed gardens and parks, green road lines and roundabouts, bio-swales, productive gardens, green roofs and walls. In each site, the challenge is to provide the best solution according to the environmental and cultural context and the citizens’ demand. The urban horticulture in synergy with NBS provides to design, realise and manage green solutions for specific problems in the urban context. NBS supplies actions able to improve urban resilience and many opportunities for improving urban quality, optimising the delivering of a mixed range of ecosystem services (ES). This chapter highlights that NBS can be used for monitoring, soil, air and water quality, water matrices and pollinator diversity. We therefore describe methods for monitoring the quality of soil, air, water matrices and pollinator diversity and abundance. In conclusion, we point out some key aspects, under an interdisciplinary perspective, in order to promote further and deeper knowledge in the application of NBS in the urban environments.
Alongside the steep reductions needed in fossil fuel emissions, natural climate solutions (NCS) represent readily deployable options that can contribute to Canada’s goals for emission reductions. We estimate the mitigation potential of 24 NCS related to the protection, management, and restoration of natural systems that can also deliver numerous co-benefits, such as enhanced soil productivity, clean air and water, and biodiversity conservation. NCS can provide up to 78.2 (41.0 to 115.1) Tg CO2e/year (95% CI) of mitigation annually in 2030 and 394.4 (173.2 to 612.4) Tg CO2e cumulatively between 2021 and 2030, with 34% available at ≤CAD 50/Mg CO2e. Avoided conversion of grassland, avoided peatland disturbance, cover crops, and improved forest management offer the largest mitigation opportunities. The mitigation identified here represents an important potential contribution to the Paris Agreement, such that NCS combined with existing mitigation plans could help Canada to meet or exceed its climate goals.
Harnessing nature-based climate solutions (NbCS) to help simultaneously achieve climate and conservation goals is an attractive win-win. The contribution of NbCS to climate action relies on both biogeochemical potential and the ability to overcome environmental, economic and governance constraints for implementation. As such, estimates of additional NbCS-related terrestrial biosphere storage potential range from less than 100 GtCO2 to more than 800 GtCO2. In this Review, we assess the negative emissions contributions of NbCS — including reforestation, improved forest management and soil carbon sequestration — alongside their environmental, social and governance constraints. Given near-term implementation challenges and long-term biogeochemical constraints, a reasonable value for the expected impact of NbCS is up to 100–200 GtCO2 in negative emissions for the remainder of the twenty-first century. To sustainably reach this level, focus should be on projects with clear co-benefits, and must not come at the expense of a reduction in emissions from deforestation and forest degradation, rapid decarbonization and innovation from alternative negative emissions technologies.
Key points
There is growing evidence that traditional response to floods and flood-related disaster is no longer achieving desirable results. Nature-Based Solutions (NBS) represent a relatively new response towards disaster risk reduction, water security, and resilience to climate change, which has a potential to be more effective and sustainable than traditional measures. However, in practice, these measures are still being applied at a slow rate while traditional grey infrastructure remains as a preferred choice. This can be attributed to several barriers which range from political and governance to social and technological/technical. More generally, there is a lack of sufficient knowledge base to accelerate their wider acceptance and uptake. The present work provides contribution in this direction and addresses the question of effectiveness of different types of NBS (i.e., small- and large-scale NBS) and their hybrid combinations with grey infrastructure. The work has been applied on the case of Ayutthaya, Thailand. The results suggest that the effectiveness of small-scale NBS is limited to smaller rainfall events whereas the larger (or extreme) events necessitate combinations of different kinds of measures with different scales of implementation (i.e., hybrid measures).
Coastal communities are increasingly vulnerable to climate change and its effects may push coastal ecosystems to undergo irreversible changes. This is especially true for shorebirds with the loss of biodiversity and resource-rich habitats to rest, refuel, and breed. To protect these species, it is critical to conduct research related to nature-based Solutions (NbS). Through a scoping review of scientific literature, this paper initially identified 85 articles with various ecosystem-based adaptation (EbA) strategies that could help conserve shorebird populations and promote ecotourism. Of these 85 articles, 28 articles had EbA strategies that were examined, with some like coral reefs and mangroves eliminated as they were inappropriate for this region. The scoping review identified four major EbA strategies for the Greater Niagara Region with living shorelines and beach nourishment being the most suitable, especially when combined. These strategies were then evaluated against the eight core principles of nature-based solutions protecting shorebird as well as human wellbeing. Living shoreline strategy was the only one that met all eight NbS principles. As the coastline of the region greatly varies in substrate and development, further research will be needed to decide which EbA strategies would be appropriate for each specific area to ensure their efficacy.
While climate change and biodiversity loss have exposed humanity to major systemic risks, policymakers in more than 40 countries have proposed the transition from a fossil-based to a bio-based economy as a solution to curb the risks. In the boreal region, forests have a prominent role in contributing to bioeconomy development; however, forest-based bioeconomy transition pathways towards sustainability and the required actions have not yet been identified. Participatory backcasting was employed in this study to ‘negotiate’ such pathways among Finnish stakeholders by 2060 in three forest-based value networks: forest biorefineries, fibre-based packaging and wooden multistorey construction. There are many alternative pathways, ranging from incremental to more radical, to a forest-based bioeconomy within a framework of ambitious climate and biodiversity targets. Path dependence can support incremental development on bioeconomy transition pathways, and this should be considered when planning transition towards sustainability. Orchestration of the more radical changes requires actions from legislators, raw material producers, consumers and researchers, because the possibilities for business development vary between different companies and value networks. The envisioned actions between the pathways in and across the networks, such as forest diversification and diverse wood utilisation, can offer co-benefits in climate change mitigation and biodiversity protection.
Flooding is the most frequent and damaging natural hazard globally. While nature-based solutions can reduce flood risk, they are not part of mainstream risk management. We develop a probabilistic risk analysis framework to quantify these benefits that (1) accounts for frequent small events and rarer large events, (2) can be applied to large basins and data-scarce contexts, and (3) quantifies economic benefits and reduction in people affected. Measuring benefits in terms of avoided losses enables the integration of nature-based solutions in standard cost-benefit analysis of protective infrastructure. Results for the Chindwin River basin in Myanmar highlight the potential consequences of deforestation on long-term flood risk. We find that loss reduction is driven by small but frequent storms, suggesting that current practice relying on large storms may underestimate the benefits of nature-based solutions. By providing average annual losses, the framework helps mainstream nature-based solutions in infrastructure planning or insurance practice.
Debate about what proportion of the Earth to protect often overshadows the question of how nature should be conserved and by whom. We present a systematic review and narrative synthesis of 169 publications investigating how different forms of governance influence conservation outcomes, paying particular attention to the role played by Indigenous peoples and local communities. We find a stark contrast between the outcomes produced by externally controlled conservation, and those produced by locally controlled efforts. Crucially, most studies presenting positive outcomes for both well-being and conservation come from cases where Indigenous peoples and local communities play a central role, such as when they have substantial influence over decision making or when local institutions regulating tenure form a recognized part of governance. In contrast, when interventions are controlled by external organizations and involve strategies to change local practices and supersede customary institutions, they tend to result in relatively ineffective conservation at the same time as producing negative social outcomes. Our findings suggest that equitable conservation, which empowers and supports the environmental stewardship of Indigenous peoples and local communities represents the primary pathway to effective long-term conservation of biodiversity, particularly when upheld in wider law and policy. Whether for protected areas in biodiversity hotspots or restoration of highly modified ecosystems, whether involving highly traditional or diverse and dynamic local communities, conservation can become more effective through an increased focus on governance type and quality, and fostering solutions that reinforce the role, capacity, and rights of Indigenous peoples and local communities. We detail how to enact progressive governance transitions through recommendations for conservation policy, with immediate relevance for how to achieve the next decade’s conservation targets under the UN Convention on Biological Diversity.
1. Abandonment of agricultural land is widespread in many parts of the world, leading to shrub and tree encroachment. The increase of flammable plant biomass, that is, fuel load, increases the risk and intensity of wildfires. Fuel reduction by herbivores is a promising management strategy to avoid fuel build-up and mitigate wildfires. However, their effectiveness in mitigating wildfire damage may depend on a range of factors, including herbivore type, population density and feeding patterns.
2. Here, we review the evidence on whether management with herbivores can reduce fuel load and mitigate wildfires, and if so, how to identify suitable management that can achieve fire mitigation objectives while providing other ecosystem services. We systematically reviewed studies that investigated links between herbivores, fire hazard, fire frequency and fire damage.
3. We found that, in general, herbivores reduce fuel load most effectively when they are mixed feeders, when grazing and browsing herbivores are combined and when herbivore food preferences match the local vegetation. In some cases, the combination of herbivory with other management strategies, such as mechanical clearing, is necessary to reduce wildfire damage.
4. Synthesis and Applications. We conclude that herbivores have the capacity to mitigate wildfire damage, and we provide guidance for grazing management for wildfire mitigation strategies. As areas undergoing land abandonment are particularly prone to wildfires, the maintenance or promotion of grazing by domestic or wild herbivores is a promising tool to reduce wildfire risk in a cost-effective way, while also providing other ecosystem services. Relevant land-use policies, including fire suppression policies, agricultural and forest(ry) policies could incentivise the use of herbivores for better wildfire prevention.
Climate change poses significant threats to wellbeing and livelihoods of people and the ecosystems in many Small Island Developing States (SIDS). Adaptation solutions must counteract these threats while also supporting development in vulnerable SIDS. Suitable options need to ensure that connections between the social, economic, and environmental dimensions of socio-economic systems are defined in a way that can support how decisions are made (and by whom) and how these can impact on other parts of these systems. This is particularly important in many Pacific SIDS, where communities practise customary natural resource management and continue to rely on local natural resources. In this study, we model the anticipated impacts of climate change and the benefits of the ecosystem-based adaptation (EbA) approaches on community wellbeing in Vanuatu. To do this, we applied participatory and expert elicitation methods to develop a Bayesian network model, which was designed to evaluate community wellbeing responses at four explicit spatial scales. The model includes both acute and chronic impacts of climate change, the impact of coral bleaching, and the potential loss of Vanuatu’s fringing coral reefs. The model predicts that all proposed EbA interventions will have a positive impact on wellbeing in all four locations to some degree, by either directly improving the integrity of Vanuatu’s ecosystems or by protecting these ecosystems as a positive spill-over of related actions. Significantly, it also predicts that if climate change exceeds 1.5 °C of warming, the costs of achieving the same level of wellbeing are increased.
The lack of urgent action to reverse biodiversity loss is partly due to the complex nature of biodiversity as a feature of our planet. Subsequently, policymakers receive an often-confusing variety of narratives on why biodiversity matters, which makes it difficult to link biodiversity loss and risks to the attainment of sustainable development. Making this link clearer calls for a multidimensional perspective on biodiversity to reassess what we value, facilitate mainstreaming and support national decision-making. We propose a co-produced Multidimensional Biodiversity Index to connect biodiversity science to the political agenda that accounts for the diversity of values underpinning nature–human relationships.
Land degradation continues to be an enormous challenge to human societies, reducing food security, emitting greenhouse gases and aerosols, driving the loss of biodiversity, polluting water, and undermining a wide range of ecosystem services beyond food supply and water and climate regulation. Climate change will exacerbate several degradation processes. Investment in diverse restoration efforts, including sustainable agricultural and forest land management, as well as land set aside for conservation wherever possible, will generate co-benefits for climate change mitigation and adaptation and more broadly for human and societal well-being and the economy. This review highlights the magnitude of the degradation problem and some of the key challenges for ecological restoration. There are biophysical as well as societal limits to restoration. Better integrating policies to jointly address poverty, land degradation, and greenhouse gas emissions and removals is fundamental to reducing many existing barriers and contributing to climate-resilient sustainable development.
Given the worldwide plans for extensive tree planting we urgently need to understand how and where implementation will contribute to goals such as those for carbon sequestration. We used a long-term, large-scale native reforestation project in the Scottish Highlands to assess the response of carbon storage and other ecosystem functions to reforestation and grazing exclusion. We measured above-ground carbon, topsoil carbon, topsoil nitrogen, decomposition rates, soil invertebrate feeding activity, tree regeneration, and ground-layer and moss height at 14 sites that are in the early stages of reforestation and fenced to exclude grazing. Reforestation areas were compared to unforested and mature forest areas that are both grazed and ungrazed, using 10 × 10 m plots. Above-ground carbon in the reforestation plots (1.4 kg/m² [95% CI: 0.6, 2.6], average age 20 years since reforestation) was c. 8% of the mature forest plots (17.1 kg/m² [13.1, 21.8]). Topsoil carbon was lower in the reforestation plots (18.78 kg/m² [11.79, 25.78]) than in the unforested (29.82 kg/m² [24.34, 35.29]) or mature forest (31.39 kg/m² [22.91, 39.88]) plots. Responses of other functions to the reforestation and grazing interventions varied. Our results suggest that reforestation may trigger carbon loss from areas with high initial soil carbon even with low disturbance establishment, at least in the short term. Our work emphasises where we lack knowledge: on the potential for long-term re-accumulation of soil carbon under semi-natural native reforestation, soil carbon sequestration in the deeper soil layers and the response of soil carbon to natural regeneration.
As storm-driven coastal flooding increases under climate change, wetlands such as saltmarshes are held as a nature-based solution. Yet evidence supporting wetlands’ storm protection role in estuaries—where both waves and upstream surge drive coastal flooding—remains scarce. Here we address this gap using numerical hydrodynamic models within eight contextually diverse estuaries, simulating storms of varying intensity and coupling flood predictions to damage valuation. Saltmarshes reduced flooding across all studied estuaries and particularly for the largest—100 year—storms, for which they mitigated average flood extents by 35% and damages by 37% ($8.4 M). Across all storm scenarios, wetlands delivered mean annual damage savings of $2.7 M per estuary, exceeding annualised values of better studied wetland services such as carbon storage. Spatial decomposition of processes revealed flood mitigation arose from both localised wave attenuation and estuary-scale surge attenuation, with the latter process dominating: mean flood reductions were 17% in the sheltered top third of estuaries, compared to 8% near wave-exposed estuary mouths. Saltmarshes therefore play a generalised role in mitigating storm flooding and associated costs in estuaries via multi-scale processes. Ecosystem service modelling must integrate processes operating across scales or risk grossly underestimating the value of nature-based solutions to the growing threat of storm-driven coastal flooding.
To conserve global biodiversity, countries must forge equitable alliances that support sustainability in traditional pastoral lands, fisheries-management areas, Indigenous territories and more.
Negative CO2 emissions are a key mitigation measure in emission scenarios consistent with temperature limits adopted by the Paris Agreement. It is commonly assumed that the climate–carbon cycle response to a negative CO2 emission is equal in magnitude and opposite in sign to the response to an equivalent positive CO2 emission. Here we test the hypothesis that this response is symmetric by forcing an Earth system model with positive and negative CO2 emission pulses of varying magnitude and applied from different climate states. Results indicate that a CO2 emission into the atmosphere is more effective at raising atmospheric CO2 than an equivalent CO2 removal is at lowering it, with the asymmetry increasing with the magnitude of the emission/removal. The findings of this study imply that offsetting positive CO2 emissions with negative emissions of the same magnitude could result in a different climate outcome than avoiding the CO2 emissions.
Minimising the environmental impacts of biofuel production is an urgent global challenge. Over the next decade, increased demand for sugarcane-based ethanol in Brazil could result in over one million hectares of the nation’s native forest and grassland being replaced directly by sugarcane or indirectly by displaced crops and pastureland. Here we integrate future ethanol demand scenarios in Brazil within a spatially-explicit planning framework aimed at minimising impacts of ethanol-driven agricultural expansion on aboveground carbon stocks and 453 species of immediate conservation concern. We show that ethanol-driven agricultural expansion that is blind to carbon and biodiversity values would release 44.9 million tonnes of CO2 equivalent (MtCO2eq), and would impact habitat for at least 273 species. When compared to this conservation-blind scenario, agricultural expansion that avoids carbon and biodiversity values would reduce emissions by 87% (5.8 MtCO2eq) and would avoid impacts on habitat for 113 species. These findings are immediately relevant to policy makers seeking to guide ethanol-driven land-use change away from important environmental areas in Brazil. Our planning methodology can also be extended to other natural areas at risk of bioenergy-driven agricultural expansion.
Amazonia hosts the Earth’s largest tropical forests and has been shown to be an important carbon sink over recent decades. This carbon sink seems to be in decline, however, as a result of factors such as deforestation and climate change. Here we investigate Amazonia’s carbon budget and the main drivers responsible for its change into a carbon source. We performed 590 aircraft vertical profiling measurements of lower-tropospheric concentrations of carbon dioxide and carbon monoxide at four sites in Amazonia from 2010 to 2018. We find that total carbon emissions are greater in eastern Amazonia than in the western part, mostly as a result of spatial differences in carbon-monoxide-derived fire emissions. Southeastern Amazonia, in particular, acts as a net carbon source (total carbon flux minus fire emissions) to the atmosphere. Over the past 40 years, eastern Amazonia has been subjected to more deforestation, warming and moisture stress than the western part, especially during the dry season, with the southeast experiencing the strongest trends. We explore the effect of climate change and deforestation trends on carbon emissions at our study sites, and find that the intensification of the dry season and an increase in deforestation seem to promote ecosystem stress, increase in fire occurrence, and higher carbon emissions in the eastern Amazon. This is in line with recent studies that indicate an increase in tree mortality and a reduction in photosynthesis as a result of climatic changes across Amazonia.
The formulation of management plans as required by EU environmental policies such as the Floods Directive may facilitate the uptake of nature-based solutions (NBS) into practice. Previous research has indicated that the uptake of NBS in water management plans is still low and hindered by various elements of the existing water governance system. However, research so far neglected the role of water managers as “plan-makers” of solution strategies and programs of measures, as well as their beliefs in choosing certain measures in the plan-making process. The aim of this study is to shed more light on the plan-makers’ reasoning for integrating, or not integrating, NBS into specific flood risk management plans (FRMPs). We conducted ten qualitative interviews with plan-makers from Germany and adopted a grounded theory approach to identify their beliefs that underlie the process of formulating FRMPs as well as their perceived role in this process. The analysis reveals a dominance of shared substantive and relational beliefs that are obstructive to a greater uptake of NBS in FRMPs. In particular, identified beliefs about NBS often do not align with their self-perception of their role in being the “plan-makers”. We present a differentiated portrait of water managers as key actors in the decision-making on FRMPs, illustrating that while water managers are belonging to the same distinct professional group with a similar social role in the decision-making process, they do not necessarily share the same preferences.
Afforestation plays an important role in soil carbon storage and water balance. However, there is a lack of information on deep soil carbon and water storage. The study investigates the effect of returning farmland to the forest on soil carbon accumulation and soil water consumption in 20-m deep soil profile in the hilly and gully region of the Chinese Loess Plateau. Four sampling sites were selected: Platycladus orientalis (Linn.) Franco forest (PO: oriental arborvitae), Pinus tabulaeformis Carr. Forest (PT: southern Chinese pine), apple orchard (AO) and farmland (FL, as a control). Soil organic carbon (SOC) and soil inorganic carbon (SIC) content were measured in 50-cm sampling intervals of 20-m soil profiles, as well as the associated factors (e.g. soil water content). The mean SOC content of PT was the highest in the 1–5 m layer and that of FL was the lowest (p < 0.05). Compared with FL, the SOC storages of PO, PT and AO increased by 2.20, 6.33 and 0.90 kg m−2 (p > 0.05), respectively, in the whole profile. The SIC content was relatively uniform throughout the profile at all land-use types and SIC storage was 9–10 times higher than SOC storage. The soil water storage of PO, PT and AO was significantly different from that of FL with a decrease of 1169.32, 1161.60 and 1139.63 mm, respectively. After the 36-yrs implementation of the “Grain for Green” Project, SOC in 20 m soil profiles increased as a water depletion cost compared with FL. Further investigation is still needed to understand the deep soil water and carbon interactions regarding ecological restoration sustainability in the Northern Loess Plateau.
“Nature’s contributions to people” (NCP) is designed to provide space for the recognition of diverse and evolving culturally mediated ideas about what people derive from, and co-produce with, nature. Its origins, along with the IPBES conceptual framework in which it is embedded, is transdisciplinary, action-oriented, and inclusive and also embraces pluralism. NCP provides both generalizing and context-specific perspectives and analytical tools that can be interwoven and enables diverse actors to represent nature-people interactions for different scales, audiences, and decision-makers. NCP therefore can be used to understand and communicate the ways in which ongoing biodiversity decline may affect the complex relationships between people and nature. This Primer presents NCP in accessible language, highlights its unique contribution as a tool for plural valuation of nature in conservation assessments, clarifies common misconceptions, and provides examples of the innovative ways NCP has already been applied around the world.
Forests play a key role in humanity’s current challenge to mitigate climate change thanks to their capacity to sequester carbon. Preserving and expanding forest cover is considered essential to enhance this carbon sink. However, changing the forest cover can further affect the climate system through biophysical effects. One such effect that is seldom studied is how afforestation can alter the cloud regime, which can potentially have repercussions on the hydrological cycle, the surface radiation budget and on planetary albedo itself. Here we provide a global scale assessment of this effect derived from satellite remote sensing observations. We show that for 67% of sampled areas across the world, afforestation would increase low level cloud cover, which should have a cooling effect on the planet. We further reveal a dependency of this effect on forest type, notably in Europe where needleleaf forests generate more clouds than broadleaf forests.