The islands of the Caribbean are particularly susceptible to the effects of climate change due to their low-lying coastal areas and location within the Atlantic basin’s hurricane belt. The UK Overseas Territory of Anguilla is one such island. The predicted increase in the severity of hurricanes and sea-level rise is highly likely to increase the flood risk of already vulnerable island communities. In this study, flood risk and erosion models are used to prioritise opportunity areas for nature-based restoration and to identify those that would have the greatest impact on coastal and in-land flood risk reduction. Two study sites in Anguilla were selected to highlight this ecologically-based modelling approach; Cove Bay and Pond, a degraded sand dune system and brackish pond, and the East End Pond, an Important Bird and Biodiversity Area that floods following heavy rainfall events. At the coastal site, the restoration of mangroves, sand dunes and coral reefs have the potential to provide flood risk reduction up to 500 m inland and protect homes, infrastructure and tourism developments. For the in-land East End Pond, areas of high erosion risk were predominately identified as bare or disturbed land within 1 km of the pond’s basin. Restoration of these areas was identified as having the greatest impact on reducing flood risk. The identification of optimal areas for habitat restoration and modelling the positive impact that habitat restoration can have in reducing flood risk are important tools that can be used to inform the implementation of nature-based solutions and also to advocate and justify such management activities to policy makers and landowners.
Geographical Subregion: Latin America & Caribbean
Latin America & Caribbean
Tropical deforestation impacts the climate through complex land–atmosphere interactions causing local and regional warming. However, whilst the impacts of deforestation on local temperature are well understood, the regional (nonlocal) response is poorly quantified. Here, we used remote-sensed observations of forest loss and dry season land–surface temperature during the period 2001 to 2020 to demonstrate that deforestation of the Amazon caused strong warming at distances up to 100 km away from the forest loss. We apply a machine learning approach to show nonlocal warming due to forest loss at 2–100 km length scales increases the warming due to deforestation by more than a factor 4, from 0.16 K to 0.71 K for each 10-percentage points of forest loss. We estimate that rapid future deforestation under a strong inequality scenario could cause dry season warming of 0.96 K across Mato Grosso state in southern Brazil over the period 2020 to 2050. Reducing deforestation could reduce future warming caused by forest loss to 0.4 K. Our results demonstrate the contribution of tropical deforestation to regional climate warming and the potential for reduced deforestation to deliver regional climate adaptation and resilience with important implications for sustainable management of the Amazon.
Most of the world’s nations (around 130) have committed to reaching net-zero carbon dioxide or greenhouse gas (GHG) emissions by 2050, yet robust policies rarely underpin these ambitions. To investigate whether existing and expected national policies will allow Brazil to meet its net-zero GHG emissions pledge by 2050, we applied a detailed regional integrated assessment modelling approach. This included quantifying the role of nature-based solutions, such as the protection and restoration of ecosystems, and engineered solutions, such as bioenergy with carbon capture and storage. Our results highlight ecosystem protection as the most critical cost-effective climate mitigation measure for Brazil, whereas relying heavily on costly and not-mature-yet engineered solutions will jeopardise Brazil’s chances of achieving its net-zero pledge by mid-century. We show that the full implementation of Brazil’s Forest Code (FC), a key policy for emission reduction in Brazil, would be enough for the country to achieve its short-term climate targets up to 2030. However, it would reduce the gap to net-zero GHG emissions by 38% by 2050. The FC, combined with zero legal deforestation and additional large-scale ecosystem restoration, would reduce this gap by 62% by mid-century, keeping Brazil on a clear path towards net-zero GHG emissions by around 2040. While some level of deployment of negative emissions technologies will be needed for Brazil to achieve and sustain its net-zero pledge, we show that the more mitigation measures from the land-use sector, the less costly engineered solutions from the energy sector will be required. Our analysis underlines the urgent need for Brazil to go beyond existing policies to help fight climate emergency, to align its short- and long-term climate targets, and to build climate resilience while curbing biodiversity loss.
Tropical forest recovery is fundamental to addressing the intertwined climate and biodiversity loss crises. While regenerating trees sequester carbon relatively quickly, the pace of biodiversity recovery remains contentious. Here, we use bioacoustics and metabarcoding to measure forest recovery post-agriculture in a global biodiversity hotspot in Ecuador. We show that the community composition, and not species richness, of vocalizing vertebrates identified by experts reflects the restoration gradient. Two automated measures – an acoustic index model and a bird community composition derived from an independently developed Convolutional Neural Network – correlated well with restoration (adj-R² = 0.62 and 0.69, respectively). Importantly, both measures reflected composition of non-vocalizing nocturnal insects identified via metabarcoding. We show that such automated monitoring tools, based on new technologies, can effectively monitor the success of forest recovery, using robust and reproducible data.
Early in August this year, a high-profile summit was held in Belém, Brazil, where the eight Amazonian countries discussed the future of the Amazon. The nations recognized that the Amazon is very close to reaching a tipping point for turning into a degraded ecosystem. The result of their discussions was the Belém Declaration, an ambitious plan to protect and conserve the Amazon forests and to support Indigenous Peoples and local communities. Concern arose, however, because they failed to agree on attaining zero deforestation by 2030 and on avoiding new explorations in the Amazon for fossil fuel. The Declaration also lacks specific and measurable indicators. The ministers of Foreign Affairs therefore have a very important role in further refining the agenda and deadlines so that the Belém Declaration can be implemented.
For over three decades, science has pointed to the risks of the Amazon reaching a tipping point. Several recent studies now demonstrate how close it is: The dry season over southern Amazon has lengthened by 4 to 5 weeks over the past 40 years, the mortality of wet-loving tree species has increased, and the loss of trees is turning the forests into a carbon source rather than a carbon sink.
The Cerrado biome in Brazil is the most biodiverse savannah in the world1 and has a key role in stabilizing both the local and the global climate, storing carbon and providing fresh water to the country2. Yet, the Cerrado has little protection and is being converted for agriculture at an alarming rate. Recently released official data reveal that, in 2022, deforestation in the biome rose for the third consecutive year3. The area cleared was 25% higher than the previous year, reaching 10,689 km² (ref. 3), rivalling the rates of deforestation in the Brazilian Amazon (12,479 km²), despite the Cerrado being only half the size3. Almost three-quarters of that conversion took place in the MATOPIBA agricultural frontier, where nearly 25% of Cerrado’s soybean harvest is planted4. The current high rates of conversion even jeopardize the future of agricultural production in the Cerrado. The loss of the Cerrado has contributed to extreme climate events over the past decade5, which increased surface-sensible heat flux, reduced evapotranspiration and crop yields and threatened the feasibility of multi-cropping systems6, as well as exacerbated land concentration and farmers’ indebtedness.
A major concern for the world’s ecosystems is the possibility of collapse, where landscapes and the societies they support change abruptly. Accelerating stress levels, increasing frequencies of extreme events and strengthening intersystem connections suggest that conventional modelling approaches based on incremental changes in a single stress may provide poor estimates of the impact of climate and human activities on ecosystems. We conduct experiments on four models that simulate abrupt changes in the Chilika lagoon fishery, the Easter Island community, forest dieback and lake water quality—representing ecosystems with a range of anthropogenic interactions. Collapses occur sooner under increasing levels of primary stress but additional stresses and/or the inclusion of noise in all four models bring the collapses substantially closer to today by ~38–81%. We discuss the implications for further research and the need for humanity to be vigilant for signs that ecosystems are degrading even more rapidly than previously thought.
The coming decades will define whether the
Amazon – home to more than 28 million inhabitants,
198 indigenous peoples, and harbouring the most
biodiverse forest, the largest freshwater reservoir
and the largest tropical bloc for climate regulation
on the planet – will become the great catalyst
for Brazil’s low-carbon economy. Or whether, in
the opposite direction, the Amazon will reach an
irreversible point of degradation, deepening current
inequalities and jeopardizing the stability and
competitiveness of the country’s entire economy.
How to guide the Legal Amazon towards a
decarbonization trajectory, transforming the region’s
economy so that it grows, generates opportunities,
values local cultures and environmental assets,
while fighting inequality and deforestation? This
question motivated the 76 researchers who signed
the New Economy for the Amazon report.
The study combines different techniques and
knowledge to present a unique depiction of the
Legal Amazon’s current economy, bringing to
light the region’s economic and environmental
relations with the rest of Brazil and the world.
The study focuses on carbon-intensive sectors
that must change course in order to become
a relevant part of a standing forest economy,
more suited to the challenges of this century.
The study further explores the role of the
bioeconomy, revealing a vigorous activity hitherto
invisible to conventional instruments used
to measure economic activity. Although it is
based on the secular form of production of the
original peoples, constantly innovated by local
technologies developed in Amazonian villages,
rural areas and cities, the bioeconomy remains
underestimated in terms of its current impact
and future potential. The work provides visibility
to these activities, demonstrating their relevance
as a solution for the region’s future economy.
The report also assesses the economic performance
of the Legal Amazon under different scenarios,
comparing the current trajectory, which has
been driving degradation, with alternative
decarbonization scenarios, especially in the
agricultural, livestock and energy sectors.
More than comparing GDP and job creation results,
as economic performance is traditionally assessed,
the New Economy for the Amazon gives shape to a
qualitative analysis of that which is wanted for the
future – and there is no future for Brazil without
the Amazon. The results show that it is impossible
for the country to reach its Paris Agreement
targets and contribute to curbing global warming
without eliminating deforestation in the Amazon.
Even assuming that deforestation is eliminated,
it will still be necessary to restore large areas of
the forest and adopt new ways of generating and
consuming energy, whether in rural or urban areas.
This report proposes a transition that generates
quality jobs and opportunities for the region’s
citizens, while driving important changes in the rest
of the country. The New Economy for the Amazon
can be the great catalyst for the decarbonization
of the entire Brazilian economy and the greatest
opportunity for economic and social development
in the country’s contemporary history.
The risks from climate change are ever-growing, especially in more vulnerable and exposed regions such as coastlines. The rise in sea level and increase in the frequency and intensity of climate-induced coastal hazards are threatening the increasing coastal populations. Brazil, with its 8,500 km of coast, is one of the countries most at risk from coastal flooding and erosion. Nature-based solutions have been suggested as climate adaptation strategies with the greatest potential to counteract coastal hazards stemming from sea-level rise and safeguard coastal cities. However, there is still a knowledge gap in the scientific literature on the effectiveness of nature-based solutions, especially at large spatial scales in Central and South America. Here, we assessed the risks from climate-induced hazards of coastal erosion and flooding related to sea-level rise on the Brazilian coast, and the effectiveness of nature-based solutions as climate adaptation strategies. We reveal that nature-based shoreline protection can reduce by 2.5 times the risks to the Brazilian coastline. The loss of existing natural habitats would substantially increase the area and population at risk from these climate-induced hazards. Worrisomely, legal mechanisms to protect these natural habitats are few and being weakened. Only 10% of the coastal natural habitats are within protected areas, and these alone do not ensure coastal protection, as our results indicate that the loss of unprotected natural habitats has about the same risk as the total absence of natural habitats. Our results warn of the severe consequences of the continued loss of natural habitats along the coast. Thus, actions towards the maintenance and protection of coastal habitats are paramount for climate adaptation and to ensure the well-being and livelihoods of coastal populations. Brazil has a central role in demonstrating the benefits of strategies based on nature-based solutions for shoreline protection, favoring their implementation worldwide. We provide both the natural habitat maps and the maps with model results with spatial and numerical information so readers can explore the relations between the natural habitats and coastal risk indexes at a sub-national level and foster their use by local stakeholders.
Brazil’s nine Amazonian states, here collectively referred to as Amazônia, include some of the world’s richest ecosystems, including the Amazon rainforest and parts of the Cerrado savanna and Pantanal wetlands. The region is also among Brazil’s poorest socioeconomically. As a result, sustainable, inclusive development of Amazônia calls for raising living standards while protecting natural forests. A Balancing Act for Brazil’s Amazonian States: An Economic Memorandum explores how a recalibrated development approach can achieve these goals. In the shorter term, there is an urgent need to halt deforestation–a massive destruction of natural wealth that poses risks to the climate and economy. Amazônia is Brazil’s deforestation hot spot, and the Amazon rainforest is approaching tipping points into broad and permanent forest loss. Reversing the recent increase in deforestation requires stronger land and forest governance, including land regularization and more effective law enforcement. In the longer term, both Brazil and Amazônia need a new growth model. This model would be anchored in productivity rather than resource extraction and it would diversify the export basket beyond commodities. A more balanced structural transformation requires the lagging urban sectors, such as manufacturing and services, to step up to promote economic growth, reduce pressure on the agricultural frontier, and generate jobs for Brazil and Amazônia’s largely urban populations. The public-good value of Amazônia’s forests could generate conservation finance linked to verifiable reductions in deforestation. Such financing would support a new development approach, combining forest protection, productivity, balanced structural transformation, sustainable production techniques (including the bioeconomy), and other measures to address the needs of Amazônia’s urban and rural populations. This approach must also heed the needs and interests of Amazônia’s traditional communities. Given both the value and the fragility of Amazônia’s ecosystems, coupled with considerable socioeconomic local needs, the stakes are high—for Amazônia, Brazil, and the world.
The Brazilian Atlantic Forest (BAF) is a global biodiversity hotspot, but its carbon sink capacity, especially in the subtropical portion, is poorly understood. We aimed to evaluate the relationship between biodiversity measures (i.e., taxonomic, functional, and phylogenetic diversity) and net carbon change across subtropical BAF, testing whether there is a win–win situation in the conservation of biodiversity and carbon sink capacity across forests of distinct ages. We obtained the net carbon change from 55 permanent plots, from early successional to old-growth forests, by combining the carbon gains and losses across two censuses. We found that subtropical BAF are on average acting as a carbon sink, but carbon gains and losses varied a lot across plots, especially within late successional/old-growth forests. The carbon sink was consistent across different forest ages, and we did not find a relationship between biodiversity and net carbon change in subtropical BAF. Therefore, conservation programs should aim at both targets in order to maximize the protection of biodiversity and carbon capture across the secondary and old-growth subtropical BAF, especially in a scenario of global changes.
Many tropical forestlands are experiencing changes in land-tenure regimes, but how these changes may affect deforestation rates remains ambiguous. Here, we use Brazil’s land-tenure and deforestation data and quasi-experimental methods to analyze how six land-tenure regimes (undesignated/untitled, private, strictly-protected and sustainable-use protected areas, indigenous, and quilombola lands) affect deforestation across 49 spatiotemporal scales. We find that undesignated/untitled public regimes with poorly defined tenure rights increase deforestation relative to any alternative regime in most contexts. The privatization of these undesignated/untitled lands often reduces this deforestation, particularly when private regimes are subject to strict environmental regulations such as the Forest Code in Amazonia. However, private regimes decrease deforestation less effectively and less reliably than alternative well-defined regimes, and directly privatizing either conservation regimes or indigenous lands would most likely increase deforestation. This study informs the ongoing political debate around land privatization/protection in tropical landscapes and can be used to envisage policy aligned with sustainable development goals.
Zero-deforestation supply chain policies that leverage the market power of commodity buyers to change agricultural producer behavior can reduce forest clearing in regions with rapid commodity expansion and weak forest governance. Yet leakage—when deforestation is pushed to other regions—may dilute the global effectiveness of regionally successful policies. Here we show that domestic leakage offsets 43-50% of the avoided deforestation induced by existing and proposed zero-deforestation supply chain policies in Brazil’s soy sector. However, cross-border leakage is insignificant (<3%) because soybean production is displaced to existing U.S. farmland. Eliminating deforestation from the supply chains of all firms exporting Brazilian soy to the EU or China from 2011-2016 could have reduced net global deforestation by 2% and Brazilian deforestation by 9%. Thus, if major tropical commodity importers (e.g., the EU) require traders to eliminate deforestation from their supply chains, it could help bend the curve on global forest loss.
To counteract undesirable impacts of climate change, several different mitigation instruments have been proposed to sequester carbon through reforestation or avert greenhouse gas emissions due to land use change through forest carbon offset projects. Such projects will require an explicit focus on equitable benefit sharing to generate sustainable and alternative livelihoods. However, research on the impacts of forest carbon offset projects for individuals and communities has often been conducted without baseline data or counterfactuals built into the research methods. We conducted a study in a small Indigenous community in eastern Panama with participants and non-participants in a forest carbon offset project, across wealth groups. In this mixed methods study, participants and non-participants completed surveys before, during, and after implementation over 14 years to assess changes to natural and financial assets. We also assessed major concerns and perceived benefits of the carbon offset project via open-ended questions. Quantitative data show that participants continued to engage in reforestation practices even after payment cessation. Quantitative data also suggest carbon offset payments provided financial stability for poorer participants to diversify into other sources of income over time, while income inequality remained stable across wealth groups. Qualitative data indicate that the greatest benefit of the carbon offset project for participants was economic security for future generations, while concerns about basic needs like food and money declined over time for both participants and non-participants. This research suggests that forest carbon offset projects can be effective for encouraging long-term adoption of forestry practices, specifically reforestation and agroforestry, while providing social co-benefits for rural livelihoods, across wealth dimensions.
Sustainable management of intact tropical peatlands is crucial for climate change mitigation, for biodiversity conservation and to support the livelihoods of local communities. Here, we explore whether sustainable fruit harvesting from Mauritia flexuosa palms could support these linked goals by increasing fruit production and incomes across the 2.8 million hectares of the most carbon-dense ecosystem in Amazonia: the lowland peatlands of northeastern Peru. M. flexuosa is dioecious, and fruits are typically harvested by felling female palms; the proportion of female palms therefore provides a good indicator of the health of a stand. Across 93 widely distributed sites, we found that the proportion of female palms increases with travel time to the urban market, and overall, fruit harvesting has halved the current potential production and income from this resource. However, significantly more female palms are found where fruit are harvested by climbing. We estimate that region-wide uptake of climbing could eventually increase potential fruit production by 51% and increase its gross value to US$62 ± 28.2 million yr–1. These findings demonstrate the high cost of unsustainable resource extraction in Neotropical forests and outline a practical path to conserve and sustainably exploit one of the most carbon-rich landscapes on the planet.
To address climate change and meet global commitments, nature-based climate (NbCS) solutions i.e. actions that aim to address climate change in sustainable way, are becoming increasingly popular. This is often expressed in so called “green pledges” that promote large scale programs of tree planting, often in plantations. Establishment of such plantations could deliver benefits to biodiversity, but this is not guaranteed, and recommendations on how to manage nature-based solutions (NbS) for biodiversity are limited and not embedded in scientific knowledge. Evidence from landscape ecology can inform general principles of NbCS design. Here, we synthesise evidence and make recommendations that can help “green pledges” to benefit biodiversity conservation. We call for an integrated approach, where NbCS tree planting projects move beyond carbon storage to create functional and diverse habitats providing multiple long-term services while safeguarding biodiversity.
- 1. The environmental benefits and lower implementation costs of (assisted) natural forest regrowth (NFR) compared to tree planting qualify it as a viable strategy to scale up forest restoration. However, NFR is not suitable in all places, because the potential for forest regeneration depends on the socio-environmental context and differs greatly over space and time. Therefore, it is critical to quantify the potential contribution of NFR for reaching forest restoration targets and complying with environmental policies.
- 2. Here, we quantify the socio-environmental consequences of NFR by considering four targets differing in restored area in the Atlantic Forest (6, 8, 15 and 22 Mha). We quantified the compliance with environmental policies, expected distribution of natural and restored vegetation within the biome and social fairness (distribution of restoration efforts and costs within small, medium and large-sized properties) of two hypothetical forest restoration scenarios.
- 3. We show that large-scale forest restoration prioritizing the areas with the highest potential for NFR (Scenario I) allows us to comply with one-third of the current environmental debt in the Atlantic Forest. Furthermore, this scenario disproportionately burdens specific types of land use, increases socioeconomic inequalities and concentrates restoration activities in regions in which the natural vegetation cover is already high.
- 4. By contrast, Scenario II—eradicating the environmental debt that results from environmental policies, then prioritizing areas with the lowest overall restoration costs until reaching the restoration targets—is socially fairer and maximizes compliance with environmental policies. Its outcomes are more homogeneously distributed among counties and small, medium and large-sized properties from the Brazilian Atlantic Forest. Despite doubling the implementation costs, the lower overall restoration costs in Scenario II result from significantly lower opportunity costs than in Scenario I.
- 5. Synthesis and application. The environmental, social and economic outputs of large-scale forest restoration in the Atlantic Forest can be maximized when NFR and tree planting are balanced (Scenario II). To achieve compliance with forest restoration commitments, we thus advocate for the site-specific selection of the best forest restoration strategy to guarantee social fairness and compliance with environmental policies at minimum overall restoration costs.
Understanding where people depend the most on natural resources for their basic human needs is crucial for planning conservation and development interventions. For some people, nature is a direct source of food, clean water, and energy through subsistence uses. However, a high direct dependency on nature for basic needs makes people particularly sensitive to changes in climate, land cover, and land tenure. Based on more than 5 million household interviews conducted in 85 tropical countries, we identified where people highly depend on nature for their basic needs. Our results show that 1.2 billion people, or 30% of the population across tropical countries, are highly dependent on nature. In places where people highly depend on nature for their basic needs, nature-based strategies that protect, restore or sustainably manage ecosystems must be carefully designed to promote inclusive human development alongside environmental benefits.
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.
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.
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.
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.
Ecological infrastructure refers to naturally functioning ecosystems that deliver valuable services to people, such as filtered water and disaster risk reduction. With natural resources becoming scarcer, there is a growing interest in reinvesting in naturally functioning ecosystems in the form of ecological infrastructure, with the assumption that ecological infrastructure complements engineered infrastructure. In many low- and middle-income countries, ecological infrastructure interventions are seen as a key strategy to simultaneously alleviate poverty and improve ecosystem functioning. However, the socio-economic outcomes of ecological infrastructure investments remain poorly documented. We address this knowledge gap by synthesizing research (n = 53 cases) that analyses how ecological infrastructure investments affect ten different socio-economic dimensions, such as income and food security in low- and middle-income countries. We find that ecological infrastructure investments primarily lead to positive outcomes for short-term income and natural capital, whereas positive outcomes for other socio-economic dimensions are less frequently observed. Cases with a high degree of participant involvement in the early implementation of ecological infrastructure investments are significantly more likely to capture positive outcomes across a variety of socio-economic dimensions. Analogously, cases spanning multiple methods – rather than adopting either a qualitative or a quantitative approach – report positive outcomes across more dimensions.
The production of sufficient food for an increasing global population while conserving natural capital is a major challenge to humanity. Tree-mediated ecosystem services are recognized as key features of more sustainable agroecosystems but the strategic management of tree attributes for ecosystem service provision is poorly understood. Six agroforestry and tree cover transition studies, spanning tropical/subtropical forest zones in three continents, were synthesized to assess the contribution of tree cover to the conservation of biodiversity and ecosystem services. Loss of native earthworm populations resulted in 76% lower soil macroporosity when shade trees were absent in coffee agriculture. Increased tree cover contributed to 53% increase in tea crop yield, maintained 93% of crop pollinators found in the natural forest and, in combination with nearby forest fragments, contributed to as much as 86% lower incidence for coffee berry borer. In certain contexts, shade trees contributed to negative effects resulting from increases in abundance of white stem borer and lacebugs and resulted in 60% reduction of endangered tree species compared to forest. Managing trees for ecosystem services requires understanding which tree species to include and how to manage them for different socio-ecological contexts. This knowledge needs to be shared and translated into viable options with farming communities.