Afforestation is considered a cost‐effective and readily available climate change mitigation option. In recent studies afforestation is presented as a major solution to limit climate change. However, estimates of afforestation potential vary widely. Moreover, the risks in global mitigation policy and the negative trade‐offs with food security are often not considered. Here we present a new approach to assess the economic potential of afforestation with the IMAGE 3.0 integrated assessment model framework. In addition, we discuss the role of afforestation in mitigation pathways and the effects of afforestation on the food system under increasingly ambitious climate targets. We show that afforestation has a mitigation potential of 4.9 GtCO2/year at 200 US$/tCO2 in 2050 leading to large‐scale application in an SSP2 scenario aiming for 2°C (410 GtCO2 cumulative up to 2100). Afforestation reduces the overall costs of mitigation policy. However, it may lead to lower mitigation ambition and lock‐in situations in other sectors. Moreover, it bears risks to implementation and permanence as the negative emissions are increasingly located in regions with high investment risks and weak governance, for example in Sub‐Saharan Africa. Afforestation also requires large amounts of land (up to 1,100 Mha) leading to large reductions in agricultural land. The increased competition for land could lead to higher food prices and an increased population at risk of hunger. Our results confirm that afforestation has substantial potential for mitigation. At the same time, we highlight that major risks and trade‐offs are involved. Pathways aiming to limit climate change to 2°C or even 1.5°C need to minimize these risks and trade‐offs in order to achieve mitigation sustainably.
Archives: Publications
While the benefits humans gain from ecosystem functions and processes are critical in natural resource-dependent societies with persistent poverty, ecosystem services as a pathway out of poverty remain an elusive goal, contingent on the ecosystem and mediated by social processes. Here, we investigate three emerging dimensions of the ecosystem service-poverty relationship: economic contribution of provisioning ecosystem services to the household livelihood mix, social-ecological systems producing different bundles of ecosystem services and material wealth versus reported life satisfaction. We analyse these relationships in Bangladesh, using data from a bespoke 1586-household survey, stratified by seven social-ecological systems in the delta coastal region. We create poverty lines to ensure comparability with traditional poverty measures that overlook environmental factors and subjective measurements of well-being. We find that any contribution of ecosystem service-based income to the livelihood mix decreases the likelihood of the incidence of poverty, and of individuals reporting dissatisfaction. We find no relationship between the incidence of material poverty and the specific social-ecological systems, from agriculture to fishery-dominated systems. However, the probability of the household head being dissatisfied was significantly associated with social-ecological system. Individuals living in areas dominated by export-oriented shrimp aquaculture reported lower levels of life satisfaction as an element of their perceived well-being. These results highlight the need for social policy on poverty that accounts for the diversity of outcomes across social-ecological systems, including subjective as well as material dimensions of well-being. National poverty reduction that degrades ecosystem services can have negative implications for the subjective wellbeing of local populations.
We elevate the undervalued role of wetland protective services for mitigating disastrous consequences of unprecedented weather-related events for human communities. Scientific evidence increasingly reveals that wetlands play critical hydrologic roles in landscapes, helping to mitigate flood, drought, and, in some cases, fire risks. However, wetland protective services have not received sufficient policy action. We propose national wetland commissions, modeled after the concept of lake and river commissions, as one way to strategically link wetland protection to other societal objectives, including human disaster risk planning, infrastructure investments, and climate adaptation strategies. We offer an example applicable to the United States, describing an institutional design for a National Interagency Wetland Commission. We suggest it could be patterned after existing federal commissions statutorily created by Congress with delegated administrative and regulatory authority and designated independent agency status within the executive branch. It is time for bold and innovative policy action to incorporate wetland protective services into societies’ defenses against extreme weather events.
There is growing awareness that ‘nature-based solutions’ (NbS) can help to protect us from climate change impacts while slowing further warming, supporting biodiversity and securing ecosystem services. However, the potential of NbS to provide the intended benefits has not been rigorously assessed. There are concerns over their reliability and cost-effectiveness compared to engineered alternatives, and their resilience to climate change. Trade-offs can arise if climate mitigation policy encourages NbS with low biodiversity value, such as afforestation with non-native monocultures. This can result in maladaptation, especially in a rapidly changing world where biodiversity-based resilience and multi-functional landscapes are key. Here, we highlight the rise of NbS in climate policy—focusing on their potential for climate change adaptation as well as mitigation—and discuss barriers to their evidence-based implementation. We outline the major financial and governance challenges to implementing NbS at scale, highlighting avenues for further research. As climate policy turns increasingly towards greenhouse gas removal approaches such as afforestation, we stress the urgent need for natural and social scientists to engage with policy makers. They must ensure that NbS can achieve their potential to tackle both the climate and biodiversity crisis while also contributing to sustainable development. This will require systemic change in the way we conduct research and run our institutions. This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.
As the severity of the triple challenges of global inequality, climate change and biodiversity loss becomes clearer, governments and international development institutions must find effective policy instruments to respond. We examine the potential of social assistance policies in this context. Social assistance refers to transfers to poor, vulnerable and marginalized groups to reduce their vulnerability and livelihood risks, and to enhance their rights and status. Substantial public funds support social assistance programmes globally. Collectively, lower- and middle-income countries spend approximately 1.5% of their GDP on social assistance annually. We focus on the potential of paid employment schemes to promote effective ecosystem stewardship. Available evidence suggests such programmes can offer multiple benefits in terms of improvements in local ecosystems and natural capital, carbon sequestration and local biodiversity conservation. We review evidence from three key case studies: in India (the Mahatma Gandhi National Rural Employment Guarantee Scheme), Ethiopia (the Productive Safety Nets Programme) and Mexico (the Temporary Employment Programme). We conclude that, to realize the potential of employment-based social assistance for ecosystem benefits it will be necessary to address two challenges: first, the weak design and maintenance of local public works outputs in many schemes, and second, the concern that social protection schemes may become less effective if they are overburdened with additional objectives. Overcoming these challenges requires an evolution of institutional systems for delivering social assistance to enable a more effective combination of social and environmental objectives. This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.
Better land stewardship is needed to achieve the Paris Agreement’s temperature goal, particularly in the tropics, where greenhouse gas emissions from the destruction of ecosystems are largest, and where the potential for additional land carbon storage is greatest. As countries enhance their nationally determined contributions (NDCs) to the Paris Agreement, confusion persists about the potential contribution of better land stewardship to meeting the Agreement’s goal to hold global warming below 2°C. We assess cost-effective tropical country-level potential of natural climate solutions (NCS)—protection, improved management and restoration of ecosystems—to deliver climate mitigation linked with sustainable development goals (SDGs). We identify groups of countries with distinctive NCS portfolios, and we explore factors (governance, financial capacity) influencing the feasibility of unlocking national NCS potential. Cost-effective tropical NCS offers globally significant climate mitigation in the coming decades (6.56 Pg CO2e yr−1 at less than 100 US$ per Mg CO2e). In half of the tropical countries, cost-effective NCS could mitigate over half of national emissions. In more than a quarter of tropical countries, cost-effective NCS potential is greater than national emissions. We identify countries where, with international financing and political will, NCS can cost-effectively deliver the majority of enhanced NDCs while transforming national economies and contributing to SDGs. This article is part of the theme issue ‘Climate change and ecosystems: threats, opportunities and solutions’.
Seagrass meadows are an important wetland habitat that have been degraded globally but have an important carbon storage role. In order to expand the restoration of these productive and biodiverse habitats methods are required that can be used for large scale habitat creation across a range of environmental conditions. The spreading of seagrass seeds has been proven to be a successful method for restoring seagrass around the world, however in places where tidal range is large such methods become limited by resultant water movements. Here we describe and test a method for deploying seagrass seeds of the species Zostera marina over large scales using a new, simple method “Bags of Seagrass Seeds Line (BoSSLine).” This method involved planting seeds and sediment using natural fiber hessian bags deployed along strings anchored onto the seabed. When deployed in a suitable environment 94% of bags developed mature seagrass shoots, unfortunately one site subjected to a large storm event resulted in sediment burial of the bags and no seed germination. Bags were filled with 100 seeds with each leading to the development of 2.37 ± 2.41 mature shoots (206 ± 87 mm in length) 10 months after planting. The method was proven successful however the experiments illustrated the need to ensure habitat suitability prior to their use. Low seed success rate was comparable to other restoration studies, however further trials are recommended to ensure ways to improve this rate. In conclusion, this study provides evidence for an effective, simple method “Bags of Seagrass Seeds Line (BoSSLine)” for deploying seeds of the seagrass Zostera marina over large scales.
Marine reserves can be effective conservation and fishery management tools, particularly when their design accounts for spatial population connectivity. Yet climate change is expected to significantly alter larval connectivity of many marine species, questioning whether marine reserves designed today will still be effective in the future. Here we predict how alternative marine reserve designs will affect fishery yields. We apply a range of empirically-grounded scenarios for future larval dispersal to fishery models of seven species currently managed through marine reserves in the nearshore waters in Southern California, USA. We show that networks of reserves optimized for future climate conditions differ substantially from networks designed for today’s conditions. However, the benefits of redesign are modest: a set of reserves designed for current conditions commonly produces outcomes within 10 percent of the best redesigned network, and far outperforms haphazardly designed networks. Thus, investing in the strategic design of marine reserves networks today may pay dividends even if the networks are not modified to keep up with environmental change.
Peatlands are wetland ecosystems that accumulate dead organic matter (i.e., peat) when plant litter production outpaces peat decay, usually under conditions of frequent or continuous waterlogging. Collectively, global peatlands store vast amounts of carbon (C), equaling if not exceeding the amount of C in the Earth’s vegetation; they also encompass a remarkable diversity of forms, from the frozen palsa mires of the northern subarctic to the lush swamp forests of the tropics, each with their own characteristic range of fauna and flora. In this review we explain what peatlands are, how they form, and the contribution that peatland science can make to our understanding of global change. We explore the variety in formation, shape, vegetation type, and chemistry of peatlands across the globe and stress the fundamental features that are common to all peat-forming ecosystems. We consider the impacts that past, present, and future environmental changes, including anthropogenic disturbances, have had and will have on peatland systems, particularly in terms of their important roles in C storage and the provision of ecosystem services. The most widespread uses of peatlands today are for forestry and agriculture, both of which require drainage that results in globally significant emissions of carbon dioxide (CO2), a greenhouse gas (GHG). Climatic drying and drainage also increase the risk of peat fires, which are a further source of GHG emissions [CO2 and methane (CH4)] to the atmosphere, as well as causing negative human health and socioeconomic impacts. We conclude our review by explaining the roles that paleoecological, experimental, and modeling studies can play in allowing us to build a more secure understanding of how peatlands function, how they will respond to future climate- and land-management-related disturbances, and how best we can improve their resilience in a changing world.
Transitions literature regards technologies as critical components in shifting systems towards sustainability, which has informed the development of the technology-oriented Technological Innovation System (TIS) framework. The emerging discourse on nature-based solutions (NBS) – multifunctional nature-integrated spatial planning and design innovations – raises the question to what extent TIS can account for the development and diffusion of NBS. Following a literature review, we present the Nature-Based Innovation System (NBIS) framework delineating critical factors for urban nature-based innovation. We find both commonalities and differences between TIS and NBIS, suggesting that the roles of place-based dynamics, agency and governance structure are more central to nature-based innovation, and market formation is more central to technological innovation. This has implications for the study of sustainability transitions, which has likely underplayed the potential of innovations at the nexus of socio-technical and socio-ecological systems. Future research is needed to refine the NBIS framework, for example by studying evolutionary developmental trajectories.
Ecosystem‐based adaptation (EbA) relies upon the capacity of ecosystems to buffer communities against the adverse impacts of climate change. Maintaining ecosystems that deliver critical services to communities can also provide co‐benefits beyond adaptation, such as climate mitigation and protection of biological diversity and livelihoods. EbA has to a limited extent drawn upon indigenous‐and local knowledge (ILK) for defining critical services and for implementing EbA in decision‐making. This is a paradox given that the primary focus of EbA is to enable communities to adapt to climate change. The purpose of this study was to elucidate EbA strategies that take into account the knowledge of Sámi reindeer herders about pastures in tundra regions. We first examined what constitutes critical services through a synthesis of data and literature. We thereafter used content analysis of 91 land use cases from 2010–2018 to investigate to what extent the herders’ knowledge and maps over seasonal pastures and migratory routes are used in local decision‐making. Finally, we propose EbA strategies of relevance to Sámi communities and pastoral communities elsewhere. Our analysis revealed that reindeer herders and organizations representing their interests perceived threats from green energy development, tourism, recreation, public road construction and powerlines. These threats included the loss of key habitats and the loss of connectivity for migration between seasonal pastures. Pastoralists’ knowledge is incorporated through participatory tools to protect the ecosystems and services crucial for pastoralists, but multiple competing land uses result in incremental loss of pastures regardless. Synthesis and application. Protecting pasture ecosystems and the services they deliver, including the connectivity between pastures, are necessary EbA strategies to buffer the adverse effects of climate change. Drawing on pastoralists’ knowledge to elicit EbA strategies can inform decision‐making, but it is equally important to implement this knowledge for prioritizing adaptation needs in the assessment of competing land use.
Nature-based solutions (NbS) is the latest contribution to the green concept family. NbS is defined as actions based in nature addressing societal challenges. In this study, we lean on the concept boundary object, broken down into three analytical categories: use, core ideas and granularities, to explore the cohesive and fragmenting powers of the NbS concept, and discuss its future role in green space governance. The study is based on a structured, qualitative review of 112 scientific peer-reviewed publications that use the term NbS. Most publications are from 2017 or later, highlighting the novelty of the NbS concept. The concept has a strong footing in the European urban context. Flood mitigation and functional ecosystems and biodiversity conservation are the most targeted sustainability goals in the publications, and a diversity of solutions are considered. There is a close link between the NbS concept, green infrastructure, and the ecosystem service concept, indicating a path dependency in its uptake and use. The publications demonstrate a low level of integration of the NbS concept (i.e. it is commonly used as a buzz word). Most empirical studies focus solely on environmental benefits delivered by NbS, and few studies assess social, economic, and environmental benefits together, which is a central ambition of the concept. We conclude that the NbS concept is working on the boundaries between different scientific disciplines and between science and policy. Depending on how the research community deals with identified temporal, epistemological and ontological granularities, we conclude that the concept has three potential developmental pathways; broader and deeper, biased with stickiness to older green concepts and an empty buzz word.
There is growing international interest in better managing soils to increase soil organic carbon (SOC) content to contribute to climate change mitigation, to enhance resilience to climate change and to underpin food security, through initiatives such as international ‘4p1000’ initiative and the FAO’s Global assessment of SOC sequestration potential (GSOCseq) programme. Since SOC content of soils cannot be easily measured, a key barrier to implementing programmes to increase SOC at large scale, is the need for credible and reliable measurement/monitoring, reporting and verification (MRV) platforms, both for national reporting and for emissions trading. Without such platforms, investments could be considered risky. In this paper, we review methods and challenges of measuring SOC change directly in soils, before examining some recent novel developments that show promise for quantifying SOC. We describe how repeat soil surveys are used to estimate changes in SOC over time, and how long‐term experiments and space‐for‐time substitution sites can serve as sources of knowledge and can be used to test models, and as potential benchmark sites in global frameworks to estimate SOC change. We briefly consider models that can be used to simulate and project change in SOC and examine the MRV platforms for SOC change already in use in various countries/regions. In the final section, we bring together the various components described in this review, to describe a new vision for a global framework for MRV of SOC change, to support national and international initiatives seeking to effect change in the way we manage our soils.
Inclusion of ecosystem-based approaches in the governmental masterplan for tsunami mitigation in Palu, Indonesia may make the city a rare case study for ecological disaster risk reduction in tropical biodiversity hotspots. Such case studies are a key pillar of the United Nations (UN) Sendai Framework to protect coastal societies globally.
The increasing impacts of climate hazards combined with the loss of coastal habitats require urgent solutions to manage risk. Storm losses continue to grow and much of them are uninsured. These losses represent an increasing burden to individuals, businesses, and can jeopardize national development goals. Pre-hazard mitigation is cost effective, but both the public and private sector struggle to finance up-front investments in it. This article explores a resilience solution that combines risk transfer (e.g., insurance) with risk reduction (e.g., hazard mitigation), which have often been treated as two separate mechanisms for disaster risk management. The combined mechanism could help align environmental and risk management goals and create opportunities for public and private investment in nature-based projects. We assessed this resilience insurance with hypothetical cases for coral reef restoration. Under conservative assumptions, 44% of the initial reef restoration costs would be covered just by insurance premium reductions in the first 5 years, with benefits amounting >6 times the total costs over 25 years. We also test the sensitivity to key factors such as project cost, risk reduction potential, insurance structure, economic exposure and discount rates. The resilience insurance mechanism is applicable to many coastlines and can help finance nature-based adaptation.
Intact Forest Landscapes (IFLs) are critical strongholds for the environmental services that they provide, not least for their role in climate protection. On the basis of information about the distributions of IFLs and Indigenous Peoples’ lands, we examined the importance of these areas for conserving the world’s remaining intact forests. We determined that at least 36% of IFLs are within Indigenous Peoples’ lands, making these areas crucial to the mitigation action needed to avoid catastrophic climate change. We also provide evidence that IFL loss rates have been considerably lower on Indigenous Peoples’ lands than on other lands, although these forests are still vulnerable to clearing and other threats. World governments must recognize Indigenous Peoples’ rights, including land tenure rights, to ensure that Indigenous Peoples play active roles in decision‐making processes that affect IFLs on their lands. Such recognition is critical given the urgent need to reduce deforestation rates in the face of escalating climate change and global biodiversity loss.
Climate change poses significant emerging risks to biodiversity, ecosystem function and associated socioecological systems. Adaptation responses must be initiated in parallel with mitigation efforts, but resources are limited. As climate risks are not distributed equally across taxa, ecosystems and processes, strategic prioritization of research that addresses stakeholder‐relevant knowledge gaps will accelerate effective uptake into adaptation policy and management action. After a decade of climate change adaptation research within the Australian National Climate Change Adaptation Research Facility, we synthesize the National Adaptation Research Plans for marine, terrestrial and freshwater ecosystems. We identify the key, globally relevant priorities for ongoing research relevant to informing adaptation policy and environmental management aimed at maximizing the resilience of natural ecosystems to climate change. Informed by both global literature and an extensive stakeholder consultation across all ecosystems, sectors and regions in Australia, involving thousands of participants, we suggest 18 priority research topics based on their significance, urgency, technical and economic feasibility, existing knowledge gaps and potential for cobenefits across multiple sectors. These research priorities provide a unified guide for policymakers, funding organizations and researchers to strategically direct resources, maximize stakeholder uptake of resulting knowledge and minimize the impacts of climate change on natural ecosystems. Given the pace of climate change, it is imperative that we inform and accelerate adaptation progress in all regions around the world.
The impacts of climate change and the socioecological challenges they present are ubiquitous and increasingly severe. Practical efforts to operationalize climate-responsive design and management in the global network of marine protected areas (MPAs) are required to ensure long-term effectiveness for safeguarding marine biodiversity and ecosystem services. Here, we review progress in integrating climate change adaptation into MPA design and management and provide eight recommendations to expedite this process. Climate-smart management objectives should become the default for all protected areas, and made into an explicit international policy target. Furthermore, incentives to use more dynamic management tools would increase the climate change responsiveness of the MPA network as a whole. Given ongoing negotiations on international conservation targets, now is the ideal time to proactively reform management of the global seascape for the dynamic climate-biodiversity reality.
Regional and global assessments periodically update what we know, and highlight what remains to be known, about the link- ages between people and nature that both define and depend upon the state of the environment. To guide research that better informs policy and practice, we systematically synthesize knowledge gaps from recent assessments of four regions of the globe and three key themes by the Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services. We assess their relevance to global sustainability goals and trace their evolution relative to those identified in the Millennium Ecosystem Assessment. We found that global sustainability goals cannot be achieved without improved knowledge on feedbacks between social and ecological systems, effectiveness of governance systems and the influence of institutions on the social distribution of ecosystem services. These top research priorities have persisted for the 14 years since the Millennium Ecosystem Assessment. Our analysis also reveals limited understanding of the role of indigenous and local knowledge in sustaining nature’s benefits to people. Our findings contribute to a policy-relevant and solution-oriented agenda for global, long-term social-ecological research.
Several Andean countries have planned to restore forest cover in degraded land to enhance the provision of multiple ecosystem services in response to international commitments such as the Bonn Challenge. Hydrological services, e.g. water supply, hydrological regulation and erosion mitigation, are particularly important to sustain the life of more than fifty million Andean people. While rapid and important forest cover changes have occurred during recent decades, critical information on the impact of forestation on hydrological services has not yet been synthesized in the context of Andean ecosystems. We define forestation as the establishment of forest by plantation or natural regeneration on areas that either had forest in the past or not. To help improve decision-making on forestation in the Andes, we reviewed the available literature concerning the impacts of forestation on water supply, hydrological regulation and mitigation of erosion and landslides. We also examined available data on the most relevant hydrological processes such as infiltration, evapotranspiration and runoff in forest stands. Hydrological services from native forests were also included as a reference state for comparing processes and services provided by forestation. Following systematic review protocols, we synthesized 155 studies using different methods, including meta-analyses and meta-regressions. Results show that forestation has had clear impacts on degraded soils, through reducing water erosion of soils and risk of moderate floods, increasing soil infiltration rate by 8 and topsoil organic matter (SOM). We found that 20 years of tree plantation was sufficient to recover infiltration rate and sediment yield close to the levels of native forests whereas SOM, soil water storage and surface runoff of native forests could not be recovered by forestation in the time scales examined. The benefits in terms of hydrological regulation are at the expense of a reduction in total water supply since forest cover was associated with higher water use in most Andean regions. Forestation with native species was underrepresented in the reviewed studies. The impact of forestation on landslides has also been largely overlooked in the Andes. At high elevations, exotic tree plantations on Andean grasslands (e.g. páramo and puna) had the most detrimental consequences since these grasslands showed an excellent capacity for hydrological regulation and erosion mitigation but also a water yield up to 40% higher than tree plantations. People engaged in forest restoration initiative should be aware that hydrological services may take some time for society and the environment to show clear benefits after forestation.
Land-use change disturbs the function of peatland as a natural carbon sink and triggers high GHG emissions. Nevertheless, historical trends and future trajectories of GHG budgets from soil do not explicitly include peatlands. Here, we provide an estimate of the past and future role of global peatlands as either a source or sink of GHGs based on scenario timelines of land conversion. Between 1850 and 2015, temperate and boreal regions lost 26.7 million ha, and tropical regions 24.7 million ha, of natural peatland. By 2100, peatland conversion in tropical regions might increase to 36.3 million ha. Cumulative emissions from drained sites reached 80 ± 20 PgCO2e in 2015 and will add up to 249 ± 38 Pg by 2100. At the same time, the number of intact sites accumulating peat will decline. In 1960 the global peatland biome turned from a net sink into a net source of soil-derived GHGs. Annual back-conversion of most of the drained area would render peatlands GHG neutral, whereas emissions from peatland may comprise 12–41% of the GHG emission budget for keeping global warming below +1.5 to +2 °C without rehabilitation.
Earth is approaching environmental thresholds that, if crossed, will create serious disruptions to ecosystems, economies, and society. To avoid the devastating effects of climate change and biodiversity loss, humanity must protect and restore native ecosystems. International conventions and organizations support forest restoration as a method for mitigating hazardous environmental shifts, but questions remain as to where and how to focus such restoration efforts. On page 76 of this issue, Bastin et al. describe a new approach that advances our understanding of global tree distribution.
The magnitude and pace of global change demand rapid assessment of nature and its contributions to people. We present a fine-scale global modeling of current status and future scenarios for several contributions: water quality regulation, coastal risk reduction, and crop pollination. We find that where people’s needs for nature are now greatest, nature’s ability to meet those needs is declining. Up to 5 billion people face higher water pollution and insufficient pollination for nutrition under future scenarios of land use and climate change, particularly in Africa and South Asia. Hundreds of millions of people face heightened coastal risk across Africa, Eurasia, and the Americas. Continued loss of nature poses severe threats, yet these can be reduced 3- to 10-fold under a sustainable development scenario
The impending threats of changing climate have been well documented across sectors. The climate risks are best addressed through increasing adaptive capacity and building resilience. Ever since the global call during the Rio Summit in 1992 for establishing sustainability indicators across sectors, there have been several studies across the world on developing indicators for sustainability, vulnerability and climate resilience. Agriculture, the most vulnerable system to changing climate, depends on the resilience of both social and ecological systems. This paper focuses on integrating the variability of climate into the agricultural sustainability measurement with a broad base of indicators and bringing in the localized factors for representing the agroecosystem specificities. The paper also aims at identifying indicators for measuring climate resilient agriculture in Indian sub-continent and developing a conceptual framework for profiling the spatial resilience across various agro-ecosystems for appropriate location-specific policy interventions. In the current study 1209 indicators used in various research studies were screened, grouped for similarity and purpose and classified based on the various dimensions viz., social, economic, ecological, etc. After a critical review based on their appropriateness as a measurable indicator, extent of overlap, relevance in Indian context and possible data availability, 41 indicators were shortlisted for validation through a comprehensive structured online survey among subject matter specialists (n = 225). The responses from the experts (n = 36) were analysed using weighted sum model (WSM) and analytic hierarchy process (AHP). The study identifies a list of 30 sustainability indicators for climate resilient agriculture in India, that are particularly suitable for different agro-ecosystems of the sub-continent. The authors advocate an action-oriented model called Climate Risk Management Package for Agriculture (CRiMPA) to aid in planning spatial/agro-ecosystem specific interventions, which in turn could strengthen the National Action Plan for Climate Change (NAPCC) of Government of India.
Oyster reefs have the potential as eco-engineers to improve coastal protection. A field experiment was undertaken to assess the benefit of oyster breakwater reefs to mitigate shoreline erosion in a monsoon-dominated subtropical system. Three breakwater reefs with recruited oysters were deployed on an eroding intertidal mudflat at Kutubdia Island, the southeast Bangladesh coast. Data were collected on wave dissipation by the reef structures, changes in shoreline profile, erosion-accretion patterns, and lateral saltmarsh movement and related growth. This was done over four seasons, including the rainy monsoon period. The observed wave heights in the study area ranged 0.1–0.5 m. The reefs were able to dissipate wave energy and act as breakwaters for tidal water levels between 0.5–1.0 m. Waves were totally blocked by the vertical relief of the reefs at water levels <0.5 m. On the lee side of the reefs, there was accretion of 29 cm clayey sediments with erosion reduction of 54% as compared to control sites. The changes caused by the deployed reefs also facilitated seaward expansion of the salt marsh. This study showed that breakwater oyster reefs can reduce erosion, trap suspended sediment, and support seaward saltmarsh expansion demonstrating the potential as a nature-based solution for protecting the subtropical coastlines.