1. Natural climate solutions (NCS), a set of land management, conservation and restoration practices aimed at mitigating climate change, have been introduced as cost-effective strategies to increase carbon (C) sequestration in terrestrial ecosystems. Improved forest management (IFM) has been identified as one NCS for working forests with substantial climate change mitigation potential. However, there is a disconnect between the policy and carbon markets context and the scientific evidence for verifiable C benefits. Further, forest soil C—the largest forest C pool—has largely been excluded from current forest management guidelines and has not been included in the IFM discourse.
2. Herein, we assess the evidence for the potential of specific IFM practices to sequester C in live forest vegetation and store it in both live and dead organic matter, and forest soil. We review IFM approaches that can enhance forest C storage, and links to best management practices and silvicultural systems to offer guidance for practitioners and researchers in the Great Lakes region of the United States. Finally, we discuss the current challenges and opportunities in including soil C in forest C management guidelines and frameworks.
In recent years, there has been a growth in scholarship on “nature-based solutions” and “natural climate solutions” to climate change. A variety of actors have argued that these natural solutions—variously involving the protection, conservation, restoration, management, enhancement, or imitation of natural ecosystems—can play a crucial role in both mitigating and adapting to climate change. What is more, by virtue of their label, natural solutions promise to be particularly attractive to the public and policymakers and have received significant media and scholarly attention. But what is natural is also social: people, acting in various social groups, can selectively emphasize or deemphasize certain characteristics of climate solutions to make them seem more or less natural. The framing of particular solutions as “natural” or “unnatural” has far-reaching implications for climate policy, but has thus far been overlooked. Here, we undertake a critical review of the ways in which natural solutions to climate change have been framed and examine the normative and practical implications of this framing. We review what counts (and what does not count) as a natural solution, and find that those labeled natural are routinely framed under technical and social appraisal criteria as being more beneficial, cost effective, mature, and democratic than ostensibly artificial counterparts. And yet we show that, under greater scrutiny, the natural framing obscures the reality that natural solutions can be just as risky, expensive, immature, and technocratic. We conclude by reflecting on the dangers of narrowing the range of solutions considered natural and indeed, of selecting solutions through recourse to “nature” at all. Rather, climate solutions must be evaluated in terms of their specific qualities, against a far broader range of framings.
The global impacts of biodiversity loss and climate change are interlinked, but the feedbacks between them are rarely assessed. Areas with greater tree diversity tend to be more productive, providing a greater carbon sink, and biodiversity loss could reduce these natural carbon sinks. Here, we quantify how tree and shrub species richness could affect biomass production on biome, national and regional scales. We find that GHG mitigation could help maintain tree diversity and thereby avoid a 9–39% reduction in terrestrial primary productivity across different biomes, which could otherwise occur over the next 50 years. Countries that will incur the greatest economic damages from climate change stand to benefit the most from conservation of tree diversity and primary productivity, which contribute to climate change mitigation. Our results emphasize an opportunity for a triple win for climate, biodiversity and society, and highlight that these co-benefits should be the focus of reforestation programmes.
Terrestrial ecosystems remove about 30 per cent of the carbon dioxide (CO2) emitted by human activities each year1, yet the persistence of this carbon sink depends partly on how plant biomass and soil organic carbon (SOC) stocks respond to future increases in atmospheric CO2 (refs. 2,3). Although plant biomass often increases in elevated CO2 (eCO2) experiments4,5,6, SOC has been observed to increase, remain unchanged or even decline7. The mechanisms that drive this variation across experiments remain poorly understood, creating uncertainty in climate projections8,9. Here we synthesized data from 108 eCO2 experiments and found that the effect of eCO2 on SOC stocks is best explained by a negative relationship with plant biomass: when plant biomass is strongly stimulated by eCO2, SOC storage declines; conversely, when biomass is weakly stimulated, SOC storage increases. This trade-off appears to be related to plant nutrient acquisition, in which plants increase their biomass by mining the soil for nutrients, which decreases SOC storage. We found that, overall, SOC stocks increase with eCO2 in grasslands (8 ± 2 per cent) but not in forests (0 ± 2 per cent), even though plant biomass in grasslands increase less (9 ± 3 per cent) than in forests (23 ± 2 per cent). Ecosystem models do not reproduce this trade-off, which implies that projections of SOC may need to be revised.
To counter increasing CO2 emissions and plant biodiversity loss, ecological restoration has been proposed as a means to sequester carbon as well as to increase species diversity in tropical landscapes. Here we examine how natural regeneration is associated with changing plant diversity and carbon stocks in the Atlantic Forest of southern Brazil. Aboveground carbon stocks and plant species diversity (using taxonomic, functional, phylogenetic and conservation metrics) were estimated in areas undergoing natural regeneration, ranging in age from seven to >80 years. Aboveground carbon, diversity and conservation metrics increase rapidly and concomitantly over time during forest natural regeneration, but even with carbon increase over time, we found the maximum taxonomic and phylogenetic diversity possible for the region. These results show the importance of considering regeneration as an alternative to increase carbon stocks, diversity, and species conservation in carbon-focused restoration plans. Our results showed co-benefits between carbon stocks, diversity, and conservation. Diversity (taxonomic, functional, and phylogenetic) increases along with carbon stocks, but functional evenness does not. Age of the areas also influences co-benefits, as they increase over time. Thus, we demonstrate that ecological restoration not only sequesters carbon and has benefits with respect to climate change but is also responsible for increasing biodiversity and conservation. This mutualism between different benefits of natural regeneration attends to a variety of international concerns.
The Billion Trees Afforestation Project (BTAP) was launched in the Khyber Pakhtunkhwa (KP) province of Pakistan to conserve existing forests and to increase the area under forest cover. It also aimed to restore environmental conditions, promote rural livelihoods and reduce poverty. To improve the effectiveness of afforestation projects, it is essential to know the role of various factors and their impacts on community participation in landscape restoration. However, these factors and their impacts remain unexplored for the BTAP. This study identifies the factors that influenced rural household participation in the BTAP in Pakistan. The data were collected from participants and nonparticipants in the BTAP as well as from various officials. We employed both qualitative and quantitative methods to analyze the data. The results of the focus group discussions and the professional evaluation of the BTAP revealed that participant farmers enjoyed all the benefits of the project at the individual and community levels. However, the project provided only partial benefits to nonparticipant farmers at both levels. The household-level results showed that age, income from forest resources, a friendly relationship with forest department staff, a risk-bearing attitude and membership or involvement in village development committee activities had positive and significant effects on farmer participation, while disputes over land and forest resources, household size and experience with/dependence on livestock farming had negative and significant impacts on farmer participation in the BTAP. Our results suggest that policymakers and project designers should pay more attention to the factors that hindered farmer participation in the BTAP. The participation of landless and disadvantaged groups in the 10-BTAP should be increased to ensure equal and widespread benefits for all users and to ensure a win-win situation of sustainable management of the forest, the environment and livelihood opportunities for all types of forest users.
The climate mitigation potential of urban nature-based solutions (NBSs) is often perceived as insignificant and thus overlooked, as cities primarily pursue NBSs for local ecosystem services. Given the rising interest and capacities in cities for such projects, the potential of urban forests for climate mitigation needs to be better understood. We modelled the global potential and limits of urban reforestation worldwide, and find that 10.9 ± 2.8 Mha of land (17.6% of all city areas) are suitable for reforestation, which would offset 82.4 ± 25.7 MtCO2e yr−1 of carbon emissions. Among the cities analysed, 1189 are potentially able to offset >25% of their city carbon emissions through reforestation. Urban natural climate solutions should find a place on global and local agendas.
Nature‐based solutions (NbS)—solutions to societal challenges that involve working with nature—have recently gained popularity as an integrated approach that can address climate change and biodiversity loss, while supporting sustainable development. Although well‐designed NbS can deliver multiple benefits for people and nature, much of the recent limelight has been on tree planting for carbon sequestration. There are serious concerns that this is distracting from the need to rapidly phase out use of fossil fuels and protect existing intact ecosystems. There are also concerns that the expansion of forestry framed as a climate change mitigation solution is coming at the cost of carbon rich and biodiverse native ecosystems and local resource rights. Here, we discuss the promise and pitfalls of the NbS framing and its current political traction, and we present recommendations on how to get the message right. We urge policymakers, practitioners and researchers to consider the synergies and trade‐offs associated with NbS and to follow four guiding principles to enable NbS to provide sustainable benefits to society: (1) NbS are not a substitute for the rapid phase out of fossil fuels; (2) NbS involve a wide range of ecosystems on land and in the sea, not just forests; (3) NbS are implemented with the full engagement and consent of Indigenous Peoples and local communities in a way that respects their cultural and ecological rights; and (4) NbS should be explicitly designed to provide measurable benefits for biodiversity. Only by following these guidelines will we design robust and resilient NbS that address the urgent challenges of climate change and biodiversity loss, sustaining nature and people together, now and into the future.
Scientists, corporations, mystics, and movie stars have convinced policymakers around the world that a massive campaign to plant trees
should be an essential element of global climate policy. Public dialogue
has emphasized potential benefits of tree planting while downplaying
pitfalls and limitations that are well established by social and ecological
research. We argue that if natural climate solutions are to succeed while
economies decarbonize (Griscom et al. 2017), policymakers must recognize and avoid the expense, risk, and damage that poorly designed and hastily implemented tree plantings impose on ecosystems and people.
We propose that people-centered climate policies should be developed
that support the social, economic, and political conditions that are compatible with the conservation of Earth’s diversity of terrestrial ecosystems. Such a shift in focus, away from tree planting and toward people and ecosystems, must be rooted in the understanding that natural climate solutions can only be effective if they respond to the needs of the rural and indigenous people who manage ecosystems for their livelihoods.
To motivate this shift in focus, we highlight ten pitfalls and misperceptions that arise when large-scale tree planting campaigns fail to acknowledge the social and ecological complexities of the landscapes they aim to transform. We then describe more ecologically effective and socially just strategies to improve climate mitigation efforts.
Nature-based solutions (NbS) can address climate change, biodiversity loss, human well-being and their interactions in an integrated way. A major barrier to achieving this is the lack of comprehensiveness in current carbon accounting which has focused on flows rather than stocks of carbon and led to perverse outcomes. We propose a new comprehensive approach to carbon accounting based on the whole carbon cycle, covering both stocks and flows, and linking changes due to human activities with responses in the biosphere and atmosphere. We identify enhancements to accounting, namely; inclusion of all carbon reservoirs, changes in their condition and stability, disaggregated flows, and coverage of all land areas. This comprehensive approach recognises that both carbon stocks (as storage) and carbon flows (as sequestration) contribute to the ecosystem service of global climate regulation. In contrast, current ecosystem services measurement and accounting commonly use only carbon sequestration measured as net flows, while greenhouse gas inventories use flows from sources to sinks. This flow-based accounting has incentivised planting and maintaining young forests with high carbon uptake rates, resulting, perversely, in failing to reveal the greater mitigation benefit from protecting larger, more stable and resilient carbon stocks in natural forests. We demonstrate the benefits of carbon storage and sequestration for climate mitigation, in theory as ecosystem services within an ecosystem accounting framework, and in practice using field data that reveals differences in results between accounting for stocks or flows. Our proposed holistic and comprehensive carbon accounting makes transparent the benefits, trade-offs and shortcomings of NbS actions for climate mitigation and sustainability outcomes. Adopting this approach is imperative for revision of ecosystem accounting systems under the System of Environmental-Economic Accounting and contributing to evidence-based decision-making for international conventions on climate (UNFCCC), biodiversity (CBD) and sustainability (SDGs).
Urgent solutions to global climate change are needed. Ambitious tree‐planting initiatives, many already underway, aim to sequester enormous quantities of carbon to partly compensate for anthropogenic CO2 emissions, which are a major cause of rising global temperatures. However, tree planting that is poorly planned and executed could actually increase CO2 emissions and have long‐term, deleterious impacts on biodiversity, landscapes and livelihoods. Here, we highlight the main environmental risks of large‐scale tree planting and propose 10 golden rules, based on some of the most recent ecological research, to implement forest ecosystem restoration that maximizes rates of both carbon sequestration and biodiversity recovery while improving livelihoods. These are as follows: (1) Protect existing forest first; (2) Work together (involving all stakeholders); (3) Aim to maximize biodiversity recovery to meet multiple goals; (4) Select appropriate areas for restoration; (5) Use natural regeneration wherever possible; (6) Select species to maximize biodiversity; (7) Use resilient plant material (with appropriate genetic variability and provenance); (8) Plan ahead for infrastructure, capacity and seed supply; (9) Learn by doing (using an adaptive management approach); and (10) Make it pay (ensuring the economic sustainability of the project). We focus on the design of long‐term strategies to tackle the climate and biodiversity crises and support livelihood needs. We emphasize the role of local communities as sources of indigenous knowledge, and the benefits they could derive from successful reforestation that restores ecosystem functioning and delivers a diverse range of forest products and services. While there is no simple and universal recipe for forest restoration, it is crucial to build upon the currently growing public and private interest in this topic, to ensure interventions provide effective, long‐term carbon sinks and maximize benefits for biodiversity and people.
This article provides a perspective on nature-based solutions. First, the argument is developed that nature-based solutions integrate social and ecological systems. Then, theoretical considerations relating to relational values, multifunctionality, transdisciplinarity, and polycentric governance are briefly outlined. Finally, a conceptual model of the social–ecological system of nature-based solutions is synthesised and presented. This conceptual model comprehensively defines the social and ecological external and internal systems that make up nature-based solutions, and identifies theoretical considerations that need to be addressed at different stages of their planning and implementation The model bridges the normative gaps of existing nature-based solution frameworks and could be used for consistent, comprehensive, and transferable comparisons internationally. The theoretical considerations addressed in this article inform practitioners, policymakers, and researchers about the essential components of nature-based solutions. The conceptual model can facilitate the identification of social and ecological interconnections within nature-based solutions and the range of stakeholders and disciplines involved.
Forests are critical for stabilizing our climate, but costs of mitigation over space, time, and stakeholder group remain uncertain. Using the Global Timber Model, we project mitigation potential and costs for four abatement activities across 16 regions for carbon price scenarios of $5–$100/tCO2. We project 0.6–6.0 GtCO2 yr−1 in global mitigation by 2055 at costs of 2–393 billion USD yr−1, with avoided tropical deforestation comprising 30–54% of total mitigation. Higher prices incentivize larger mitigation proportions via rotation and forest management activities in temperate and boreal biomes. Forest area increases 415–875 Mha relative to the baseline by 2055 at prices $35–$100/tCO2, with intensive plantations comprising <7% of this increase. Mitigation costs borne by private land managers comprise less than one-quarter of total costs. For forests to contribute ~10% of mitigation needed to limit global warming to 1.5 °C, carbon prices will need to reach $281/tCO2 in 2055.
Awarding CO2 offset credits may incentivize seagrass restoration projects and help reverse greenhouse gas (GHG) emissions from global seagrass loss. However, no study has quantified net GHG removal from the atmosphere from a seagrass restoration project, which would require coupled Corg stock and GHG flux enhancement measurements, or determined whether the creditable offset benefit can finance the restoration. We measured all of the necessary GHG accounting parameters in the 7-km2 Zostera marina (eelgrass) meadow in Virginia, U.S.A., part of the largest, most cost-effective meadow restoration to date, to provide the first seagrass offset finance test-of-concept. Restoring seagrass removed 9,600 tCO2 from the atmosphere over 15 years but also enhanced both CH4 and N2O production, releasing 950 tCO2e. Despite tripling the N2O flux to 0.06 g m−2 yr−1 and increasing CH4 8-fold to 0.8 g m−2 yr−1, the meadow now offsets 0.42 tCO2e ha−1 yr−1, which is roughly equivalent to the seagrass sequestration rate for GHG inventory accounting but lower than the rates for temperate and tropical forests. The financial benefit for this highly successful project, $87 K at $10 MtCO2e−1, defrays ~10% of the restoration cost. Managers should also consider seagrass co-benefits, which provide additional incentives for seagrass restoration.
The climate and biodiversity crises are fundamentally connected and more integrated approaches are needed to address them effectively. To directly tackle the interconnected factors behind them, actions which
capitalize on the contributions of nature, commonly known as Naturebased Solutions (NbS), can play a more central role. The one-year delay in the 2020 Conferences of Parties to the UNFCCC and the CBD caused by the COVID-19 crisis provides a unique opportunity to bring new scientific advances to inform and strengthen the links between both international agendas and their national implementation. To facilitate the alignment and better understand the potential synergies between these agendas, there is a need to assess the role that achieving biodiversity conservation targets can play in efforts to mitigate climate change. This report presents the first results of ongoing research aiming to inform progress by making explicit and quantifying the role that achieving biodiversity conservation targets can play in securing the emissions reductions needed to meet the objectives of the Paris Agreement. This report, the first output of this effort, looks at the carbon stocks associated with areas identified as possible priorities to meet proposed global biodiversity conservation targets.
The analysis presented here identifies the regions where global action will deliver the most to achieve post-2020 biodiversity conservation goals and mitigate climate change. It shows that the strategic choice of areas to be managed for conservation, increasing such areas to 30% of land globally,
could safeguard more than 500 gigatons of carbon. When prioritizing
areas for conservation management, taking account of biodiversity and
carbon together can secure 95% of the biodiversity benefits and nearly
80% of the carbon stock that could be obtained by prioritizing based on
either value alone. [Continued]
To constrain global warming, we must strongly curtail greenhouse gas emissions and capture excess atmospheric carbon dioxide. Regrowing natural forests is a prominent strategy for capturing additional carbon, but accurate assessments of its potential are limited by uncertainty and variability in carbon accumulation rates. To assess why and where rates differ, here we compile georeferenced measurements of carbon accumulation. Climatic factors explain variation in rates better than land-use history, so we combine the field measurements with 66 environmental covariate layers to create a global, one-kilometre-resolution map of potential aboveground carbon accumulation rates for the first 30 years of natural forest regrowth. This map shows over 100-fold variation in rates across the globe, and indicates that default rates from the Intergovernmental Panel on Climate Change (IPCC) may underestimate aboveground carbon accumulation rates by 32 per cent on average and do not capture eight-fold variation within ecozones. Conversely, we conclude that maximum climate mitigation potential from natural forest regrowth is 11 per cent lower than previously reported owing to the use of overly high rates for the location of potential new forest. Although our data compilation includes more studies and sites than previous efforts, our results depend on data availability, which is concentrated in ten countries, and data quality, which varies across studies. However, the plots cover most of the environmental conditions across the areas for which we predicted carbon accumulation rates (except for northern Africa and northeast Asia). We therefore provide a robust and globally consistent tool for assessing natural forest regrowth as a climate mitigation strategy.
Land‐use/land‐cover change (LULCC) often results in degradation of natural wetlands and affects the dynamics of greenhouse gases (GHGs). However, the magnitude of changes in GHG emissions from wetlands undergoing various LULCC types remains unclear. We conducted a global meta‐analysis with a database of 209 sites to examine the effects of LULCC types of constructed wetlands (CWs), croplands (CLs), aquaculture ponds (APs), drained wetlands (DWs), and pastures (PASs) on the variability in CO2, CH4, and N2O emissions from the natural coastal wetlands, riparian wetlands, and peatlands. Our results showed that the natural wetlands were net sinks of atmospheric CO2 and net sources of CH4 and N2O, exhibiting the capacity to mitigate greenhouse effects due to negative comprehensive global warming potentials (GWPs; −0.9 to −8.7 t CO2‐eq ha−1 year−1). Relative to the natural wetlands, all LULCC types (except CWs from coastal wetlands) decreased the net CO2 uptake by 69.7%−456.6%, due to a higher increase in ecosystem respiration relative to slight changes in gross primary production. The CWs and APs significantly increased the CH4 emissions compared to those of the coastal wetlands. All LULCC types associated with the riparian wetlands significantly decreased the CH4 emissions. When the peatlands were converted to the PASs, the CH4 emissions significantly increased. The CLs, as well as DWs from peatlands, significantly increased the N2O emissions in the natural wetlands. As a result, all LULCC types (except PASs from riparian wetlands) led to remarkably higher GWPs by 65.4%−2,948.8%, compared to those of the natural wetlands. The variability in GHG fluxes with LULCC was mainly sensitive to changes in soil water content, water table, salinity, soil nitrogen content, soil pH, and bulk density. This study highlights the significant role of LULCC in increasing comprehensive GHG emissions from global natural wetlands, and our results are useful for improving future models and manipulative experiments.
Extensive ecosystem restoration is increasingly seen as being central to conserving biodiversity1 and stabilizing the climate of the Earth2. Although ambitious national and global targets have been set, global priority areas that account for spatial variation in benefits and costs have yet to be identified. Here we develop and apply a multicriteria optimization approach that identifies priority areas for restoration across all terrestrial biomes, and estimates their benefits and costs. We find that restoring 15% of converted lands in priority areas could avoid 60% of expected extinctions while sequestering 299 gigatonnes of CO2—30% of the total CO2 increase in the atmosphere since the Industrial Revolution. The inclusion of several biomes is key to achieving multiple benefits. Cost effectiveness can increase up to 13-fold when spatial allocation is optimized using our multicriteria approach, which highlights the importance of spatial planning. Our results confirm the vast potential contributions of restoration to addressing global challenges, while underscoring the necessity of pursuing these goals synergistically.
This book provides a systematic review of nature-based solutions and their potential to address current environmental challenges. In the 21st century, society is faced by rapid urbanisation and population growth, degradation and loss of natural capital and associated ecosystem services, an increase in natural disaster risks, and climate change. With growing recognition of the need to work with ecosystems to resolve these issues there is now a move towards nature-based solutions, which involve utilising nature’s ecosystem to solve societal challenges while providing multiple co-benefits. This book systematically reviews nature-based solutions from a public policy angle, assessing policy developments which encourage the implementation of nature-based solutions to address societal challenges while simultaneously providing human well-being and biodiversity benefits. This includes enhancing sustainable urbanisation, restoring degraded ecosystems, mitigating and adapting to climate change, and reducing risks from natural disasters. While nature-based solutions can be applied strategically and equitably to help societies address a variety of climatic and non-climatic challenges, there is still a lack of understanding on how best to implement them. The book concludes by providing a best practice guide for those aiming to turn societal challenges into opportunities. This book will be of great interest to policymakers, practitioners and researchers involved in nature-based solutions, sustainable urban planning, environmental management, and sustainable development generally.
Efforts to combat global climate change through forestry plantations designed to sequester carbon and promote sustainable development are on the rise. This paper analyses the trajectory of Cambodia´s first large-scale reforestation project awarded within the context of climate change mitigation. The 34,007 ha concession was formally conceived to promote sustainable resource use, livelihood improvements and emission reduction. On the ground, however, vast tracks of diverse forest landscapes are being cleared and converted to acacia monocultures, existing timber stocks are logged for market sale, and customary land users dispossessed from land and forest resources. While the project adds to an ongoing land grab crisis in Cambodia, we argue that the explicit environmental ends of the forestry concession enabled a ‘green grab’ that not only exceeds the scale of land grabs caused by conventional economic land concessions, but surprisingly also exacerbates forest logging and biodiversity loss in the area. This case demonstrates the extent to which current climate change discourses, forestry agendas and their underlying assumptions require critical revision in global policy discussions to forestall the growing problem of green grabbing in land use.
Strong decreases in greenhouse gas emissions are required to meet the reduction trajectory resolved within the 2015 Paris Agreement. However, even these decreases will not avert serious stress and damage to life on Earth, and additional steps are needed to boost the resilience of ecosystems, safeguard their wildlife, and protect their capacity to supply vital goods and services. We discuss how well-managed marine reserves may help marine ecosystems and people adapt to five prominent impacts of climate change: acidification, sea-level rise, intensification of storms, shifts in species distribution, and decreased productivity and oxygen availability, as well as their cumulative effects. We explore the role of managed ecosystems in mitigating climate change by promoting carbon sequestration and storage and by buffering against uncertainty in management, environmental fluctuations, directional change, and extreme events. We highlight both strengths and limitations and conclude that marine reserves are a viable low-tech, cost-effective adaptation strategy that would yield multiple cobenefits from local to global scales, improving the outlook for the environment and people into the future
In recent years, there has been a growing realization that improving market access for smallholders will lead to improvement in income and food security. However, market failure often limit smallholders’ fair access to market opportunities. To address this problem, a market-oriented agroforestry action research program was implemented in six sites of Kavre and Lamjung districts of Nepal between 2013 and 2016. The main objective of this paper is to investigate the changing impacts of the market-oriented agroforestry system on improving people’s livelihoods and addressing food security issues. The net-margin analysis of five priority products of agroforestry systems indicated that farmers benefitted most by a banana-based high yielding fodder system (56%) followed by Alnus-cardamom system (48%), tomato-fodder and buffalo (36%), chilli-fodder (26%) and ginger-based (25%) systems due to facilitation of market-oriented agroforestry action research services. The impact of market-oriented agroforestry intervention from a survey of 289 households, revealed that household income was increased by 37–48%, which can provide up to six additional months of food to the poorest households. This innovation has the potential to take the majority of households (63%) out of the poverty cycle while avoiding food shortage during the year. The implications of the study are that farmers must be united for collective marketing of their production and develop marketing strategies to eliminate middle men for better return. Some key lessons learned for the success of this research include farmers’ own motivation, favorable environment, and the inclusion of social activities and incentives for cultivating priority products species.
The traditional knowledge of indigenous people is often neglected despite its significance in combating climate change. This study uncovers the potential of traditional ecological knowledge (TEK) from the perspective of indigenous communities in Sarawak, Malaysian Borneo, and explores how TEK helps them to observe and respond to local climate change. Data were collected through interviews and field work observations and analysed using thematic analysis based on the TEK framework. The results indicated that these communities have observed a significant increase in temperature, with uncertain weather and seasons. Consequently, drought and wildfires have had a substantial impact on their livelihoods. However, they have responded to this by managing their customary land and resources to ensure food and resource security, which provides a respectable example of the sustainable management of terrestrial and inland ecosystems. The social networks and institutions of indigenous communities enable collective action which strengthens the reciprocal relationships that they rely on when calamity strikes. Accordingly, the communities maintain their TEK through cultural festivals and oral traditions passed from one generation to another. TEK is a practical tool that helps indigenous communities adapt to climate risks and promotes socio-ecological resilience, which upholds social empowerment and sustainable resource management.
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.
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’.
