Highlights 

• Nature-based solutions (NBS) for adaptation can play a key role in managing the climate change crisis while yielding critical environmental, economic, and social benefits.
• Multi-stakeholder, multi-year, and multi-country initiatives centered on NBS have great potential to expand adaptation goals into their activities and reach more stakeholders.
• This paper is based on a literature review, an online survey of 16 initiatives’ secretariat staffs, and follow-up interviews, with a deeper dive into three initiatives: the African Forest Landscape Restoration Initiative (AFR100), Cities4Forests, and Initiative 20x20.
• Most of the NBS initiatives surveyed in this research were not designed with adaptation goals in mind yet 94 percent of staff surveyed indicated a high or moderate demand for and interest in adaptation. This paper identifies opportunities for them to integrate adaptation.
• Opportunities for NBS initiatives to address adaptation include better leveraging NBS initiatives’ comparative strengths to expand their adaptation activities; further facilitating finance and investment; and harnessing current political momentum to build the case for the effectiveness of NBS as an approach to adaptation.
• Recommendations for funders and managers of initiatives include investing in expanding existing NBS initiatives to integrate adaptation by building their mandates, functionality, inter-initiative collaboration, and staff capacity on this topic.

What Are Nature-Based Solutions and Why Do They Matter?

The term nature-based solutions captures approaches to reverse natural resource degradation and biodiversity loss while promoting sustainable development. Across ecosystems, many NBS can also protect people and nature from climate impacts, including shorter-term hazards such as flooding and longer-term threats like desertification.

Reducing these risks is paramount, especially since they disproportionately affect vulnerable and marginalized groups (such as women, Indigenous peoples, the elderly, people living in poverty, and those with disabilities) who are directly dependent on natural resources for their livelihoods and/or are physically exposed to climate impacts. These groups stand to benefit the most from nature-based climate adaptation solutions, revealing an important opportunity to advance equity outcomes. Additionally, evidence continues to emerge showing that an NBS approach can be more effective and result in greater savings, social benefits, and avoided losses than business-as-usual interventions (World Bank 2020; Chausson et al. 2020).  

The links between ecosystems and societal resilience are clear. When ecosystems degrade, communities become more vulnerable to climate risks and lose vital resources provided by nature. NBS approaches can protect livelihoods and human well-being, and help societies better adapt to the changing climate.

Key Findings

NBS initiatives have achieved important mitigation and sustainability outcomes; many could expand their impact by including adaptation. Secretariat staff of surveyed initiatives stated a strong interest in better including climate adaptation. Deliberately integrating adaptation into existing NBS initiatives would contribute to ecosystem health, social well-being, and climate resilience simultaneously.

This paper identifies key opportunities for NBS initiatives to contribute to adaptation outcomes:

• Better coordinating among NBS initiatives to incorporate and accelerate climate adaptation efforts, especially by leveraging one another’s strengths: expertise in building strategic partnerships; providing specialized technical assistance and capacity building; promoting knowledge sharing; and actively engaging initiative stakeholders
• Sharing adaptation tools and processes from adaptation-focused organizations already integrating NBS
• Continuing to invest in NBS for adaptation pilots to open the door for larger initiatives while capitalizing on existing NBS initiatives’ expertise in accessing and mobilizing finance to attract more funding for adaptation
• Maximizing the adaptation benefits that NBS can deliver to groups that disproportionally bear the brunt of both climate impacts and ecosystem degradation
• Harnessing current political momentum surrounding NBS for adaptation by improving the evidence and socioeconomic cases for them and by better communicating their benefits

NBS initiatives face multiple barriers that limit their uptake of adaptation priorities. Examples include insufficient funding to expand their activities to include adaptation and limited technical expertise on adaptation.

Recommendations

Initiatives should mainstream adaptation into their programs and activities, and better communicate the benefits of NBS for adaptation. Initiative secretariats should engage with adaptation partners and practitioners to build technical knowledge of and capacity for NBS for adaptation. They should also engage with communications specialists to better translate and raise awareness of NBS for adaptation benefits for a range of audiences.

Funders should consider investing in the expansion of existing initiatives as vehicles to incorporate and scale NBS for adaptation rather than creating new ones. Funders should encourage initiatives that largely focus on NBS for mitigation and other environmental services to include more content on adaptation, as this is a high-impact scaling opportunity to utilize initiatives’ strengths, user audiences, and established support resources.

Funders and initiatives should promote collaboration among initiatives to fill gaps, leverage initiatives’ strengths, and develop global programs that can accelerate adaptation action. A wide range of NBS initiatives has proliferated worldwide, which can fragment their impacts as an abundance of options may make the landscape more difficult for users to navigate. Initiatives have an opportunity to clarify their roles and better organize efforts, for example, by meaningfully including local governments and organizations; funders could help by encouraging multi-partner proposals.

Funders and initiatives have an opportunity to enhance monitoring, evaluation, and learning (MEL) of NBS for adaptation to strengthen the case for further action. Increased MEL and improvements to the evidence base on the benefits of NBS for adaptation will strengthen the economic, social, and environmental case for more and longer-term adaptation actions, capturing benefits for vulnerable groups. This integrated approach could result in more robust, equitable, and cost-effective solutions for cities, countries, and communities and help leverage more funding.

Funders and initiatives can do more to facilitate access to finance. NBS funders should provide flexible vehicles for financing the integration of adaptation into relevant pilots and programs, since expanding to include adaptation can enhance activities’ resilience and effectiveness. The intersectionality of NBS initiatives means they are uniquely positioned to help their users access and develop innovative financial mechanisms, which could be used to unlock climate finance for adaptation—especially from the private sector.

About This Paper

This paper seeks to understand the potential for existing NBS-centered initiatives to better incorporate climate adaptation, thereby contributing to broader adaptation efforts needed to combat the climate emergency. It explores the barriers these initiatives face to offering enhanced adaptation support, as well as existing and new opportunities for accelerating adaptation actions, while improving monitoring and evaluation and capturing lessons learned. Findings are based on an extensive literature review, a survey of the secretariat staffs of 16 initiatives, and follow-up interviews. Examples from three countries and one city illustrate the specific supporting roles that NBS initiatives can play in accelerating NBS for adaptation.

The target audiences for this paper are managers and coordinators of NBS initiatives interested in increasing their climate adaptation impact; as well as funders of NBS initiatives, including bilateral and multilateral donors. The authors also hope that the findings and recommendations in this paper are useful to adaptation practitioners and other funders in the conservation, adaptation, and sustainable development spaces, as well as city and national governments exploring nature-based measures to increase their climate resilience to mounting climate change impacts. 

1.1 Definition and Evolution of Nature-Based Solutions for Adaptation

In the early 2000s, experts reconceptualized humans’ relationship to nature-based solutions (NBS) to shift our understanding of our role from passive beneficiaries of nature conservation to proactive participants in nature protection, management, and restoration to address societal challenges (Cohen-Shacham et al. 2019). Today, NBS is used as an umbrella term that captures several approaches aiming to reverse natural resource degradation and biodiversity loss while promoting United Nations (UN) Sustainable Development Goals (SDGs) and at times building resilience to climate change impacts. These approaches include ecosystem-based adaptation, ecosystem-based mitigation, eco-disaster risk reduction, natural and/or green (and blue) infrastructure, natural climate solutions (focused on climate mitigation and carbon sequestration), engineering with nature, nature-based flood protection, and re-naturing (Cohen-Shacham et al. 2019).

A clear, universal definition of NBS does not exist, but definitions by the International Union for Conservation of Nature (IUCN), the European Commission, and the UN all highlight these solutions as powerful tools that in many cases can increase resilience and biodiversity while providing co-benefits for humans (Calliari et al. 2019; Kapos et al. 2019).

Nature and the ecosystem services it provides underpin human society—and, if managed correctly, can be the first line of defense against extreme weather events and other climate risks, such as desertification and sea level rise (Kapos et al. 2019). Although using NBS approaches to adaptation are widely practiced by international development and climate adaptation practitioners, only recently have the broader climate mitigation and conservation communities begun to better recognize the potential of ecosystem services to help meet development and climate adaptation goals (Igoe 2019).

Even though cities and countries are showing interest in nature-based solutions for adaptation, they do not always have the technical expertise or financial and other resources to plan for and implement adaptation measures, and projects are often done on a pilot basis or in an ad hoc manner (Kapos et al. 2019). NBS initiatives could tap into the knowledge and tools employed by the adaptation community to mainstream NBS for adaptation across sectors to increase the use of biodiversity and ecosystem services to help people adapt to climate change effects. This paper aims to shed light on how multi-partner NBS initiatives can contribute to adaptation solutions, as some already have, and take advantage of existing opportunities to do more.

For the purposes of this working paper, NBS are defined as actions that protect, sustainably manage, and restore natural and modified ecosystems to address societal challenges effectively and adaptively, and that simultaneously provide human well-being and biodiversity benefits (IUCN n.d.). Adaptation is defined as the process of adjusting to actual or expected climate change and its effects, the process of moderating or avoiding harm, and the ability to exploit beneficial opportunities (IPCC 2014). Resilience is the ability of a system to cope with great change or disruption (adapted from IPCC 2018).

1.2 NBS for Adaptation Bring about Many Co-benefits

The most common types of climate-related hazards to which NBS are applied are coastal threats, flooding, landslides, drought, and rising temperatures (Kapos et al. 2019). Examples of co-benefits of adopting an integrated approach to climate, development, and nature include economic savings and efficiency gains from pooling resources, and unlocked social and environmental co-benefits. Negative trade-offs can be lessened or avoided by considering how climate is expected to change in the coming years and decades, and building in respective decisions and measures to protect against these effects.

Although not all NBS activities contribute to adaptation,¹ many of them can support adaptation outcomes, in terms of protecting people and natural systems from both shorter-term hazards such as extreme heat days and longer-term threats like sea level rise and desertification (see Figure 1). This protection is especially relevant for equity reasons, given that marginalized groups, including many communities directly dependent on natural resources, are highly vulnerable to both climate change and environmental degradation. NBS can provide powerful societal benefits to vulnerable groups, such as access to water and firewood, in a way that is fair and equitable while promoting transparency and participation (Cohen-Shacham et al. 2019; IUCN 2020). Because NBS interventions often provide services for distant communities, cities, and governments, it is important to provide a clear participatory and representative process that involves local actors in decision-making, negotiations, and compensation mechanisms to prevent losses to the communities living in or near the intervention sites (Cohen-Shacham et al. 2019). Relatedly, green infrastructure can help reduce health inequalities by more fairly distributing health benefits to all of society, such as through nature-based water management techniques or green urban spaces (Pepinster 2021). Examples of overarching adaptation outcomes include enhanced food, water, and livelihood security; protection against flooding, drought, and disasters; and improved human health.

Figure 1 | Across Ecosystems, Different Nature-Based Solutions Can Work Together to Build Climate Resilience

Source: Bapna et al. 2019.

Research indicates that NBS can create or enhance natural buffers against extreme weather events and climate fluctuations that can damage physical assets and negatively impact livelihoods (Seddon et al. 2020). They can be as or more effective than alternative interventions to address climate impacts (World Bank 2020; Chausson et al. 2020; Kapos et al. 2019). For example, when compared with gray infrastructure, mangrove forests can provide a cost-effective green means of coastal protection from storms and hurricanes. One study found that, across 59 countries, mangroves can help save an estimated US$65 billion annually in avoided losses in infrastructure and human systems, including health (Earth Security 2021).

Similarly, adequate watershed management and wetland rehabilitation can prevent loss of life and property by minimizing damages from extreme storms, soil erosion, and landslides. Agroforestry, natural reservoirs, and sustainable agricultural practices can protect against seasonal variability, pests and disease, and rising temperatures, thus decreasing food insecurity and crop losses.

1.3 NBS for Adaptation Are Cost-Effective

NBS have frequently been recognized as an equal or more cost-effective approach than traditional business-as-usual solutions (e.g., built “gray” infrastructure such as dikes, dams, reservoirs, pipes, and seawalls) (UNEP 2018). The Organisation for Economic Co-operation and Development found, for example, that NBS were two to five times more cost-effective than gray infrastructure across 52 coastal defense projects in the United States and were more effective in defending against waves up to half a meter high and at increased water depth (OECD 2020). Leveraging natural capital to protect against water-security threats—projected to rise in the coming decades—represents a potential $3 trillion in avoided replacement costs by 2050 (Vörösmarty et al. 2021).

Likewise, a new study by the International Institute for Sustainable Development calculates that using nature in infrastructure projects can save governments and investors $248 billion annually, and that NBS can be up to 50 percent cheaper than gray infrastructure while providing the same infrastructure services (IISD et al. 2021). Economic savings are especially important for the world’s most climate-vulnerable countries, which are typically the least able to afford the economic brunt of climate impacts (Bapna et al. 2019).

Given the potential to expand NBS initiatives’ outcomes by broadening their missions to include adaptation, this paper identifies opportunities and support needed for initiatives to integrate adaptation as well as opportunities to accelerate adaptation action.

This section gives an overview of the many types and flavors of global NBS-centered initiatives that were targeted for this research. Through the literature review, World Resources Institute (WRI) staff and partners identified over 40 relevant initiatives, and selected a subset for surveys and interviews.

2.1 NBS-Centered Initiatives Targeted by This Paper

Thirty-six initiatives that promote NBS were identified as good targets for the research survey (for details, see Section 3 and Appendix C). The initiatives represent those working on nature-centric interventions and focused at the city and country level. Their approaches to NBS range from awareness raising to implementing on-the-ground activities, with some of the initiatives also providing funding for NBS implementation. To visualize the diversity of initiatives in terms of NBS offerings, the authors mapped each initiative using insights from desk research and input from the interviewees. The range of initiatives varies from those specific to NBS to others focused on traditional adaptation that explicitly mention adaptation in their core missions (Figure 2).

Figure 2 | The Landscape of Nature-Based Solutions Initiatives and Funders Is Diverse

Notes: By working together and embracing a crosscutting approach, initiatives can maximize co-benefits across nature, mitigation, and adaptation. Quadrants on the left include initiatives that focus on nature-based solutions (NBS) for non-adaptation purposes, while quadrants on the right show initiatives that highlight adaptation. Each NBS initiative and funder has its own unique characteristics: some may be more operational, awareness-oriented, or financial in nature.

Abbreviations: AFR100 = African Forest Landscape Restoration Initiative; UN = United Nations; NDC Partnership = Nationally Determined Contribution Partnership.

Source: Adapted from Alliance for Global Water Adaptation. 2021, unpublished.

Responses to the survey were received from 16 of the 36 initiatives surveyed, including the African Forest Landscape Restoration Initiative (AFR100), Cities4Forests, and Initiative 20x20. Details about these 16 initiatives’ objectives, NBS scopes, geographic coverages, and organizational partners, as well as the names of the 20 other initiatives surveyed, are listed in Appendix C.

The methodology applied included a mix of qualitative and (to a lesser extent) quantitative methods: a literature and document review based on desk research, an online survey with corresponding analysis of results, and semi-structured interviews.

Desk Research and Document Review

The authors reviewed gray literature such as government documents, reports and evaluations, issue papers, materials detailing case studies, and more traditional literature such as academic articles on NBS and adaptation. The team also reviewed primary documents on the websites of AFR100 (national restoration strategies and Restoration Opportunities Assessment Methodology plans), Cities4Forests (materials about its founding and relevant city-level strategies), and Initiative 20x20 (national restoration plans). This review helped inform the baseline questions for the survey and identify other active NBS initiatives.

Two-Tiered Approach to NBS Initiatives and Survey Outreach

Given WRI’s role in the management of AFR100, Cities4Forests, and Initiative 20x20, the authors had open access to the secretariat staff and to detailed information about these three initiatives. This proximity allowed for a deeper analysis of how they support adaptation through NBS and the identification of illustrative examples, described in boxes throughout the paper.

A second, broader group of external initiatives was also engaged to gain insights into the larger NBS ecosystem (initiatives involved broadly in conservation, reforestation, restoration, and other nature-based efforts; for details on how we chose these, see Appendix A). The authors reached out via email to 36 initiatives and received 67 survey responses from 16 initiatives: AFR100, Cities4Forests, CitiesWithNature, Conservation International’s Green-Gray Community of Practice, C40 Cities, Food and Land Use Coalition, Friends of EbA, Global Facility for Disaster Reduction and Recovery/World Bank’s NBS Community of Practice, Global Partnership on Forest and Landscape Restoration, Initiative 20x20, Latin American Water Funds Partnership, Nature4Cities, Naturvation, NDC Partnership, PANORAMA – Solutions for a Healthy Planet, and UrbanShift. This selection is not exhaustive given the universe of initiatives engaged in NBS globally.

Open-ended and multiple-choice questions probed the strengths and challenges of initiatives, the level of interest in and demand for adaptation, adaptation priorities and enabling conditions, and the role that NBS initiatives should play to accelerate NBS for adaptation (for questionnaire, see Appendix A). Authors analyzed and tagged responses before visualizing them in graphs.

Semi-structured Interviews

Based on a review of survey responses, follow-up interviews were undertaken with 25 staff members—chosen based on the level of engagement in implementation cases and the level of detail included in their survey responses—from the three primary initiatives to elaborate on how to overcome specific challenges and learn more about examples that highlight successful implementation of NBS for adaptation interventions (see Appendix B for the questionnaire).

Limitations

During the first weeks of the survey, WRI received a very low response rate from respondents, especially from initiatives in which WRI does not play a direct role. The authors countered this limitation by extending the survey multiple times and sending frequent, personalized reminders to respondents. It became apparent that Cities4Forests—an initiative with a large secretariat team—was proportionally overrepresented in the results (27 respondents, or 40 percent of the total, compared with other initiatives that had only a few or even single respondents). To reduce this bias, when visualizing results in a graph, the authors gave equal weight of one “point” to each initiative (regardless of the number of respondents per initiative) to better present the diversity of perspectives among initiatives.²

Our research identified a number of opportunities and strategies NBS initiatives could use to advance adaptation outcomes:

• Improving coordination among NBS initiatives and their partners to advance climate adaptation efforts
• Incorporating learning from existing adaptation-oriented organizations already focusing on NBS
• Investing in NBS for adaptation pilots to open the door for larger initiatives and employing NBS initiatives’ expertise in accessing and mobilizing finance to attract funding for adaptation
• Ensuring that the positive impacts of NBS for adaptation reach vulnerable groups that disproportionately bear the double brunt of climate impacts and ecosystem degradation
• Harnessing the current political momentum surrounding NBS for adaptation, in part by advancing the evidence and socioeconomic case for NBS for adaptation

5.1 Improving Coordination among NBS Initiatives and Their Partners

According to interviewees and survey respondents, NBS initiatives could better coordinate and collaborate with one another and relevant partners to leverage each other’s strengths to expand and scale NBS for adaptation. Initiatives could connect regional partners to share lessons and expertise as well as implementation experiences from around the globe to help national and subnational stakeholders integrate NBS for adaptation into policy and law. Such information could also help address planning and implementation needs.

To overcome the tendency of governments to approach climate challenges in a fragmented manner—including those faced by multiple sectors, for example—initiatives could engage with multiple national and subnational agencies to co-create modalities that bring traditionally siloed departments together. Initiatives could help governments encourage stakeholders and political actors to work together to implement and maintain adaptation measures at community and landscape levels. This would include involving local organizations and actors, especially since both NBS and adaptation needs are very context-specific, as illustrated by the El Salvador example in Box 2 and the Fiji example in Box 3.

5.2 Incorporating Learning from Adaptation-Oriented Organizations

Our research showed that while NBS are frequently used by the adaptation community, NBS initiatives do not typically use adaptation goals as an entry point to engage with users. Rather, initiatives “tend to be focused on the ecosystem, not the human system as much. We’re focusing on the means instead of focusing on the end,” according to an interviewee.

As global awareness of the value of NBS increases, NBS initiatives may act as forums, fostering dialogue and collaboration while increasing awareness among peer initiatives of the linkages between adaptation and NBS. More initiatives could pursue adaptation as a goal and highlight the benefits of NBS for meeting adaptation needs. Initiatives could showcase tools and techniques for NBS for adaptation to enhance knowledge exchange among communities, users, and technical communities. NBS initiatives that do not already include adaptation could also engage with dedicated adaptation initiatives and practitioners to share expertise.

A prominent example of an adaptation-focused effort is Initiative 20x20,³ which was launched at COP20 in Lima in November 2014 in support of the Bonn Challenge, the New York Declaration on Forests, and other global commitments to reduce and ultimately end deforestation.

Initiative 20x20

This country-led effort is seeking to change the dynamics of land degradation in Latin America and the Caribbean with the goal of bringing 20 million hectares of degraded land under protection and restoration by 2020 and 50 million hectares by 2030 (Figure 8). Initiative 20x20 will thereby promote resilience to climate change, improve livelihoods—especially for lower-income and rural communities—support biodiversity, and enhance water and food security across the continent.

Figure 8 | Initiative 20x20 Restoration Commitments Are in the Millions of Hectares by Country

Note: Abbreviations: mha = million hectares; B = billion; TBD = to be determined.

Source: Initiative 20x20. n.d. “Restoring Latin America’s Landscapes.” https://initiative20x20.org/restoring-latin-americas-landscapes. Accessed January 10, 2022.

To date through the initiative, 18 Latin American and Caribbean countries and three regional programs have committed to restoring more than 52 million hectares of land (or about 124 million acres, an area roughly the size of Paraguay and Nicaragua combined). These ambitions are supported by 97 technical organizations and 25 financial partners, including impact investors who have earmarked $2.5 billion in private investment for restoration activities in the region.⁴ The initiative harnesses the expertise and capacity of these partners to drive restoration forward across the region.

As the secretariat of Initiative 20x20, WRI facilitates the dialogue among governments, civil society, and the private sector to build an effective coalition that can achieve the initiative’s restoration goals. Through the Madrid Declaration on Restoration, announced in 2019, Latin American and Caribbean ministers forming part of Initiative 20x20 recognize restoration as a climate action, focused on decarbonization (Initiative 20x20 2019). The 2021 Ministerial Communication highlights restoration as both a mitigation and adaptation measure, showing a shift toward incorporating adaptation (Initiative 20x20 2021).

5.3 Investing in Pilots and Smaller NBS for Adaptation Projects to Open the Window for Broader Funding and Initiatives

Limited finance is a frequent bottleneck to scaling NBS for adaptation. Pilot funding and early-stage investment present opportunities to permit a critical mass of NBS pilots and early-stage projects to take place around the world, in some of the most challenging conditions. These first projects are also an important precursor to accessing finance to scale and move NBS for adaptation to a broader, programmatic level. There are self-sustaining programs, for example, in Guatemala and Costa Rica, where the governments have defined provisions for financing NBS within their countries’ budgets,⁵ but they first needed grant-funded opportunities to show that NBS can work for different goals, including adaptation. Box 3 exemplifies the value of NBS for adaptation pilot projects in Fijian villages and their capacity to scale.

Initiatives could facilitate access to investment finance and address the financial readiness gap that is typical of NBS projects, leveraging their expertise and networks to unlock NBS finance for adaptation (a gap noted in Figure 6). NBS for adaptation projects may be challenged to establish creditworthiness and a definite return on investment, and those who propose them may require technical assistance to quantify benefits, demonstrate cost-effectiveness, perform due diligence, conduct necessary pre-feasibility assessments, and develop business models and links with de-risking facilities. Existing NBS initiatives could help adaptation-oriented users overcome these readiness gaps by building stronger concepts and financial cases. Likewise, they could play a critical role in integrating adaptation and resilience into traditional green-gray infrastructure projects.

5.4 Improving Social Equity Outcomes

Climate change often directly impacts people living in poverty, communities that depend on natural resources for their livelihoods, and other vulnerable groups when their communities and the resources they depend on are damaged. Groups facing systemic inequities, such as ethnic minorities and women, are also disproportionately affected by climate change. Local actors often perceive these issues holistically rather than in a disconnected way, making them well-equipped to help identify adaptation priorities and measures, which are inherently local (Mfitumukiza et al. 2020).

Making the social impacts of NBS activities more beneficial and equitable is imperative. Including local actors’ perspectives and priorities in the full project cycle, including results monitoring, is key to enhancing the climate resilience of both ecosystems and vulnerable groups, and to avoiding unintended harm. Tracking these benefits would add to the evidence base of NBS for adaptation, therefore making a stronger, more visible economic and social case for action, leading to greater buy-in. For example, protecting urban forests to mitigate flooding and extreme rainfall in and around cities can protect residents living in informal settlements from climate change impacts while improving their quality of life through increased air quality (Reid 2020).

The opportunity for NBS initiatives to better identify and communicate the many benefits of NBS for adaptation to funders and partners is clear, as is the need to break down operational silos and promote the exchange of best practices and lessons learned to help vulnerable groups.

5.5 Harnessing the Current Political Momentum on NBS for Adaptation

As countries and cities grapple with climate change and place this crisis at the top of political agendas, an opportunity exists for NBS initiatives to better engage with national and subnational political leadership to promote NBS as an adaptation pathway. This increased attention presents an opportunity for NBS initiatives to further incorporate nature-based adaptation solutions and place them on the fast track toward implementation.

More than 66 percent of signatories to the Paris Agreement included NBS in their climate commitments, although the majority of these commitments have not yet translated into robust, evidence-based targets (Seddon et al. 2020). During COP26 in November 2021, NBS was a key theme and it became apparent that the climate crisis cannot be tackled without nature (Paxton 2021). Additionally, an analysis of the updated nationally determined contribution (NDC) adaptation components submitted by June 30, 2021, found that countries had committed to 89 percent more adaptation priorities with linkages to NBS in their updated NDCs compared with their first submissions (Dixit et al. 2022). While the increase was not uniform across countries, the findings reflect parties’ desire to improve commitments to nature in adaptation through the Paris Agreement’s iterative cycle of NDC enhancement. Box 4 examines the specific case of Mumbai, India, a city that is experiencing growing political will to harness NBS for adaptation goals.

Cities4Forests

Cities4Forests⁶ was launched in September 2018 at the Global Climate Action Summit in San Francisco, with 45 founding city members. It supports cities worldwide in recognizing their interdependence with the world’s forests, and helps them use their own political, economic, and cultural power to protect and manage those forests for improved human well-being. In 2021, the Cities4Forests Call to Action on Forests and Climate urged national and subnational governments to demonstrate their commitments to climate mitigation and adaptation through forests, and Cities4Forests pledged to work with cities on these issues (WRI 2021).

Cities4Forests helps its member cities prioritize exercises and other resources to better conserve, manage, and restore their inner forests (such as city trees, urban parks, and natural areas), nearby forests (such as watersheds), and faraway forests (especially tropical forests). The initiative raises awareness of the benefits of forests and other nature-based solutions—especially for climate, water, biodiversity, and human health and well-being—by inspiring political action and engagement; providing technical assistance and capacity building; and facilitating economic analysis, finance, and investment.

Cities4Forests was founded by World Resources Institute, Pilot Projects Design Collective, and the communications agency REVOLVE. The initiative currently engages 82 cities around the world, involving mayors’ offices and other city agencies such as public water utilities and offices of sustainability (Figure 9).⁷ Cities4Forests encourages peer-to-peer learning and connects cities with technical support from institutions with expertise in cities, forests, the climate crisis, water, communications, finance, policy, and social equity.

Figure 9 | Cities4Forests Has 82 City Members around the World (as of March 2022)

Source: WRI (World Resources Institute). Last updated 2022. “About Cities4Forests.” https://www.wri.org/our-work/project/cities4forests/about-cities4forests.

We present five recommendations for NBS initiatives and their funders to achieve greater adaptation outcomes in the next decade and inspire more commitments and investments. Three recommendations straddle both groups, as depicted in Figure 10.

Figure 10 | Recommendations Directed at Funders and NBS Initiative Secretariats

Note: Abbreviations: NBS = nature-based solutions; MEL = monitoring, evaluation, and learning.

Source: Authors.

6.1 Recommendations to Funders

Invest in existing initiatives as reliable vehicles to scale NBS for adaptation

Rather than fragmenting investments through other vehicles, adding adaptation content to existing initiatives is a high-impact, cost-effective scaling opportunity. Large audiences, from cities to national governments and civil society organizations, already engage with NBS initiatives. For example, Cities4Forests works with 82 cities, reaching over 300 million people, and AFR100 and Initiative 20x20 work with dozens of countries in Africa and Latin America. Funders can reach these audiences and help mainstream climate adaptation if they invest in delivering more adaptation content through existing initiatives and encourage those that focus on NBS for mitigation and other environmental services to include more adaptation in their activities.

Our survey results highlight the benefits to initiative beneficiaries, as perceived by the initiative staff, that could be tapped into. Perceived benefits include promoting information exchange; raising ambition among peers; aligning efforts with global goals, which in turn encourages higher ambitions; and demonstrating leadership at the international level. Initiatives present an already-established opportunity for funders to leverage these advantages and align them more directly with adaptation outcomes. Existing initiatives offer additional attributes: established infrastructure for engagement, economies of scale, and the chance to establish cross-initiative coordination. Another benefit is that the same city or country staff who are charged with both mitigation and adaptation often look to these initiatives for support, making initiatives an efficient means of delivering adaptation content.

6.2 Recommendations to Funders and Initiatives

Promote inter-initiative complementarity and collaboration to fill gaps, leverage initiatives’ strengths, and develop global programs that can accelerate adaptation action

The “NBS rush” experienced in the past five years has resulted in a proliferation of initiatives and organizations working on various aspects of NBS around the world. Some of these initiatives include adaptation content, while most do not. To better leverage initiatives’ unique strengths and offerings and engage initiative stakeholders in a coordinated and additive way, funders and initiative secretariats alike need to promote inter-initiative collaboration with an eye toward streamlining competing offers and meaningfully including local actors such as subnational governments and local organizations.

In addition, to unlock large pools of grant finance from multilateral agencies and governments, initiatives must do more to develop an organized strategy that does not risk duplicating efforts or employing competing approaches in similar contexts. Funders have a unique role to play here as they can require organizations and initiatives to collaborate on large proposals.

Support improvements in monitoring, learning, and evaluation of NBS for adaptation to strengthen the case for adaptation

Increasing support for more robust MEL of NBS for adaptation projects and programs would allow initiatives to better harness empirical evidence to make the economic, social, and environmental case for NBS for adaptation, which will take time and resources. As with many other sectors, MEL for NBS for adaptation is all too often an afterthought and not budgeted for. It is also often hindered by the short-term nature of donor funding, since NBS projects often require periods of more than 10 years to demonstrate appropriate impact, especially as this impact relates to adaptation and improved resilience over time of both ecosystems and vulnerable groups.

Interviewees highlighted a gap in objective and high-quality MEL for both NBS and adaptation, which presents an immediate opportunity for funders and initiatives. As the empirical evidence base for NBS for adaptation is strengthened over time, the empirical case for why it is a cost-effective way for countries, cities, and communities to meet their adaptation goals may be strengthened. More developed MEL efforts around NBS for adaptation could then capture impacts on improved resilience of human and natural systems, including benefits to marginalized groups.

Facilitate access to finance and flexible funding

To scale NBS for adaptation, initiatives can help accelerate access to finance for pilots and programs that incorporate adaptation dimensions. Interested funders of initiatives can help by recognizing the emerging opportunities from NBS and deploying more grant funding through flexible mechanisms, aimed at developing and supporting the entire ecosystem of adaptation stakeholders (governments, subnational entities, communities, businesses, and local actors), which will allow the needed expansion of proof-of-concept interventions, especially throughout the Global South.

Adaptation will not scale globally with grant funding alone, and initiatives are uniquely positioned to help their users tap into the wealth of available green finance both from the public and private spheres. Initiatives can provide capacity to their users to develop innovative financial mechanisms to access finance, including climate finance, and organize to create appropriate project standards to enable project aggregation and scaling of NBS for adaptation projects. Relatedly, initiatives can help connect financial institutions, corporations, and other interested buyers eagerly seeking to invest in natural capital projects via payment for ecosystem services, carbon and biodiversity uplift credits, and other mechanisms. By tapping into their technical expertise, harnessing unique partnerships, and convening the required constellation of finance and business communities, initiatives can help their participants unlock investment finance for adaptation interventions at scale.

6.3 Recommendation to Initiative Secretariats

Build the capacity of NBS initiatives to design and mainstream adaptation into their programs and activities, and to better communicate the benefits of NBS for adaptation

Initiative secretariats should engage with adaptation partners and practitioners to build their own technical knowledge of and capacity for NBS for adaptation. Adaptation practitioners have much knowledge to share on mainstreaming climate risk management and making the socioeconomic case on NBS for adaptation. This collaboration should also engage communications specialists who are best positioned to translate technical information on the benefits of NBS for adaptation for a range of audiences. In addition, initiatives are encouraged to invest in hiring and training climate adaptation staff who can serve both the initiatives and the initiatives’ clients (governments, cities, and so on) and to consider broadening their mandates to include adaptation.

NBS initiatives have many strengths and advantages that can help countries and communities advance climate adaptation outcomes, and they therefore could become an important part of the existing spectrum of adaptation solutions. These initiatives are strategically placed to build effective partnerships, channel technical capacity and resources, and share knowledge. Intentionally integrating decision-making and planning for climate risks into NBS enhances the resilience of both activities on the ground and initiatives’ general objectives. The adaptation community is adept at mainstreaming NBS into its practice; the NBS community can learn to mainstream and leverage adaptation as well.

Leveraging the current political momentum that exists for adaptation and NBS, and tapping into different NBS initiatives’ competitive advantages, presents a unique opportunity to accelerate scaling of NBS commitments for adaptation, greatly increasing their positive impact—especially for the vulnerable groups they both aim to protect.

In addition to AFR100, Cities4Forests, and Initiative 20x20, in which WRI plays a role, the authors administered the research survey to a broader group of NBS-centered initiatives. NBS platforms represented a wide range of setups and hierarchies ranging from informal networks to registered NGOs to government-affiliated programs. The unifying thread was the centrality of NBS within their missions and activities.

We identified which external initiatives to focus on through desk research and suggestions from a group of WRI staff, including experts from WRI’s climate resilience, forests, and cities teams, who have many years of experience collaborating with NBS initiatives and partners. The group identified a list of over 40 initiatives, with their respective missions, main activities, and contact information. Although a few initiatives do not explicitly focus on NBS (e.g., the NDC Partnership), they were included because WRI experts in the fields of restoration, forests, cities, and water confirmed that they strongly engage in NBS approaches. We sent the survey questionnaire to the 36 initiatives for which the research team found available contact information, and kept it open from June 1 to July 31, 2021. The survey was first piloted by a group of five people within WRI and then adjusted based on feedback to improve clarity and consistency.

Survey: The Role of Nature-Based Solutions Initiatives in Climate Adaptation

We understand this platform/initiative was not created with the sole intention of addressing adaptation goals. However, many nature-based solutions initiatives have the potential to contribute to increased adaptation outcomes, even if they have not had adaptation as a primary objective, and are likely already implementing some of these activities. Greater alignment and integration between adaptation and NBS can help maximize resources and co-benefits, and it is for this reason that we hope to engage with you and the broader NBS community through this survey to identify concrete ways to leverage NBS-related initiatives for greater adaptation results. We hope that this will also benefit your work by creating a space for exchange and collaboration across initiatives and within the NBS community.

The following questions are designed to provide a better understanding of how different NBS-related initiatives may be contributing to adaptation efforts and how these efforts could be scaled up. Your answers will be used to gauge interest in climate adaptation from a variety of NBS-centered initiatives and understand what additional support is needed. We are also very interested in learning and sharing information about places that are already taking advantage of NBS and climate adaptation opportunities and how these can be expanded.

Individual responses will remain anonymous and information will be aggregated at the initiative level. We do ask that you provide your name and affiliation so that we can follow up, if needed, to understand how needs compare across initiatives.

Thank you for taking the time to answer this survey. Your answers are very helpful to us as we seek ways to identify NBS-adaptation opportunities and accelerate action.

Part I: General information  

• Your first name
• Your last name
• Your email address 
• The initiative you are answering for
  • Answer format: Choose from a drop-down list of all 36 NBS initiatives identified

Part II: General features and purpose of the initiative  

1. What is the initiative doing really well? What are its biggest strengths?  
   • Answer format: Open-ended response
2. What are the main challenges and obstacles that still need to be overcome?   
   • Answer format: Open-ended response

Part III: Existing engagement on climate adaptation  

1. What level of interest and demand for adaptation has there been from stakeholders in your initiative? Stakeholders include countries, cities, businesses, communities, and partner organizations, among others, that are participating in your initiative.  
   • Answer format: Choose one of the following options
     • High: Many cities and countries are interested in climate adaptation 
     • Somewhat: Some cities and countries are interested 
     • Minimal: Have heard of only a couple of cities or countries bringing up adaptation 
     • Not at all/this is not a priority: Adaptation is not part of conversations 
2. In your opinion, what climate adaptation priorities (e.g., urban flooding, storms, heat stress, food security, water access) draw the most attention from participating stakeholders?
   • Answer format: Open-ended response
3. In your opinion, which stakeholders are frontrunners when it comes to integrating climate adaptation into their NBS projects, plans, and strategies?
   • Answer format: Open-ended response
4. From the following, which climate adaptation considerations are integrated into the initiative? Check all that apply. 
   • Climate risks and adaptation are expressly included in the initiative’s mission/objectives
   • We share information about climate adaptation with our members 
   • We provide technical guidance and support on climate adaptation 
   • We provide financial support for climate adaptation considerations 
   • No, the initiative doesn’t integrate adaptation 
   • I’m not sure 
   • Other:
5. What aspects of the initiative enable adaptation considerations to be incorporated? Check all that apply. 
   • Provision of relevant data and information 
   • Provision of specialized technical assistance/capacity
   • Greater awareness about the role of NBS for adaptation
   • Peer-to-peer learning and sharing
   • Relevant gatherings with NBS and adaptation stakeholders
   • Formation of strategic partnerships
   • Access to NBS finance
   • Other:   
6. Can you share one positive example of an on-the-ground project/activity with adaptation components that the initiative supported, and explain what went well? Please leave your email address so we can follow up with you to learn more about this case.
   • Answer format: Open-ended response
7. Can you share one example of an on-the-ground project/activity with adaptation components that the initiative supported that did not go as well and explain why that was? Please leave your email address so we can follow up with you to learn more about this case.

Part IV: Future engagement on climate adaptation  

1. In your opinion, what types of support or enabling environment could help spur more action around adaptation in NBS initiatives? Check all that apply.
   • Provision of relevant data and information
   • Provision of specialized technical assistance/capacity
   • Greater awareness about the role of NBS for adaptation
   • Peer-to-peer learning and sharing
   • Relevant gatherings with NBS and adaptation stakeholders
   • Formation of strategic partnerships
   • Access to NBS finance
   • Other:   
2. What has been the role of the NBS initiatives/platforms in raising awareness and building momentum in NBS for adaptation?  
3. What should be the role of NBS initiatives/platforms at large in the future?
4. Are you interested in engaging with similar NBS initiatives on how to leverage adaptation and findings from this project?   
   1. Yes 
   2. No 

Interviewer notes: Provide a brief overview of the project and introductions for people on the call. If recording, request consent. Aim for 30–40 minutes. 

1. Can you please share a brief overview of the initiative and your role in supporting it?   
2. What is the initiative doing really well/what are its biggest strengths that help (or could help) members integrate climate adaptation? [review specific survey response and ask for details]  
3. What are the areas the initiative/platform could improve on to better take advantage of adaptation opportunities through NBS?  [review specific survey response and ask for details]  
4. Can you tell us more about frontrunner country/city/situation X you noted in the survey as being successful in integrating NBS to address adaptation? What were the factors for success?   
5. Providing relevant data and information to enable adaptation considerations was marked as very important by survey respondents. In your experience, what type of data and information is most useful for stakeholders?   
   • Basic data on current and future climate   
   • Detailed and localized data on climate risks and adaptation options  
   • Technical knowledge and tools on how to incorporate adaptation into NBS activities  
   • Guidance to understand adaptation and NBS linkages    
   • Evidence of the effectiveness of adaptation actions   
   • Making the business case for adaptation action in NBS projects  
   • Success stories  
   • Information and lessons learned from peer initiatives/cities/countries  
   • Other:   
6. Survey respondents noted that progress integrating climate risks and adaptation measures can be slow (e.g., coordination processes) or disrupted (e.g., by administration changes, turnover, COVID-19). What have you seen that can keep momentum going and climate adaptation on the agenda?  
7. Access to funding: How has your initiative or stakeholders overcome funding barriers?  
8. What role(s) do you believe that initiatives such as yours can play to help members take action on adaptation?
9. What other types of support are needed to spur more action around adaptation in NBS initiatives?  
10. You answered “yes” to engaging with other NBS initiatives. What do you envision as the best ways to do X, Y, Z that you noted in the survey?  
11. Is there anything else you’d like to share with us about this topic before we end the interview?  

The profiles of the 16 NBS initiatives that responded to the survey are listed in Table C1.

List of Additional Relevant NBS Initiatives Surveyed:

1. Capitals Coalition (https://capitalscoalition.org/)
2. Clever Cities (https://clevercities.eu/)
3. Connecting Nature (https://connectingnature.eu/)
4. Connecting Nature Enterprise Platform (https://connectingnature.eu/cnep)
5. ECCA30 (https://infoflr.org/bonn-challenge/regional-initiatives/ecca30)
6. Friends of Ocean Action (https://www.weforum.org/friends-of-ocean-action)
7. Interfaith Rainforest Initiative (https://www.interfaithrainforest.org/)
8. Natural Capital Project (https://naturalcapitalproject.stanford.edu/)
9. Natural Infrastructure for Business (https://www.wbcsd.org/Programs/Food-and-Nature/Water/Natural-Infrastructure-for-Business)
10. Nature4Climate (https://nature4climate.org/)
11. Nature-based Solutions Initiative, University of Oxford (https://www.naturebasedsolutionsinitiative.org/)
12. Partnership for Environment and Disaster Risk Reduction (https://pedrr.org/)
13. Resilient Cities Network (https://resilientcitiesnetwork.org/)
14. Rewilding Europe (https://rewildingeurope.com/)
15. The Nature of Cities (https://www.thenatureofcities.com/)
16. ThinkNature (https://www.think-nature.eu/)
17. Nature-based Solutions Coalition (https://www.unep.org/nature-based-solutions-climate)
18. UnaLab (https://unalab.eu/en)
19. UrbanByNature (https://connectingnature.eu/urbanbynature)
20. Wealth Accounting and the Valuation of Ecosystem Services (WAVES) (https://www.wavespartnership.org/)

Abadie, L.M., L.P. Jackson, E. Sainz de Murieta, S. Jevrejeva, and I. Galarraga. 2020. “Comparing Urban Coastal Flood Risk in 136 Cities under Two Alternative Sea-Level Projections: RCP 8.5 and an Expert Opinion-Based High-End Scenario.” Ocean & Coastal Management 193. https://www.sciencedirect.com/science/article/pii/S0964569120301599.

AFR100. n.d. “Home.” https://afr100.org/. Accessed January 28, 2022.

AFR100. 2021. “Release: AFR100 Issues COP27 Challenge to Mobilize $2 Billion for Africa’s Locally Led Land Restoration Movement.” Press Release. Midrand, South Africa: AFR100. https://afr100.org/content/afr100-issues-cop27-challenge.

Bapna, M., C. Brandon, C. Chan, A. Patwardhan, and B. Dickson, lead authors. 2019. Adapt Now: A Global Call for Leadership on Climate Resilience. Global Commission on Adaptation. https://files.wri.org/s3fs-public/uploads/GlobalCommission_Report_FINAL.pdf.

BMC (Brihanmumbai Municipal Corporation). 2022. Mumbai Climate Action Plan. Mumbai: BMC. https://drive.google.com/file/d/1gU3Bnhk3UJ_wCFaMC1ognZBdsdDkQBY1/view.

C40 Cities. n.d. “Home.” https://www.c40.org/. Accessed January 28, 2022.

Calliari, E., A. Staccione, and J. Mysiak. 2019. “An Assessment Framework for Climate-Proof Nature-Based Solutions.” Science of the Total Environment 656 (March): 691–700. Doi:10.1016/j.scitotenv.2018.11.341.  

Chausson, A., B. Turner, D. Seddon, N. Chabaneix, C.A.J. Girardin, V. Kapos, I. Key, et al. 2020. “Mapping the Effectiveness of Nature-Based Solutions for Climate Change Adaptation.” Global Change Biology 26 (11): 6134–55. https://doi.org/10.1111/gcb.15310.

CitiesWithNature. n.d. “Home.” https://www.citieswithnature.org/. Accessed January 28, 2022.

Cohen-Shacham, E., A. Andrade, J. Dalton, N. Dudley, M. Jones, C. Kumar, S. Maginnis, et al. 2019. “Core Principles for Successfully Implementing and Upscaling Nature-Based Solutions.” Environmental Science & Policy 98 (August): 20–29. doi:10.1016/j.envsci.2019.04.014. 

DeNoia Aronsohn, M. 2017. “Mumbai May Be Vulnerable to Future Hurricanes.” Initiative on Extreme Weather and Climate. New York: Columbia University. http://extremeweather.columbia.edu/2017/10/05/mumbai-may-be-vulnerable-to-future-hurricanes/.

Dixit, A., M. Kim, R. O’Connor, M. Dyck, and G. Ferrarin. 2022. “State of the Nationally Determined Contributions: Enhancing Adaptation Ambition.” Working Paper. Washington, DC: World Resources Institute.

Earth Security. 2021. The Blended Finance Playbook for Nature-Based Solutions. London: Earth Security. https://earthsecurity.org/report/the-blended-finance-playbook-for-nature-based-solutions/.  

FEBA (Friends of Ecosystem-based Adaptation). n.d. “Welcome to FEBA.” https://friendsofeba.com/. Accessed January 28, 2022.

FOLU (Food and Land Use Coalition). n.d. “About the Food and Land Use Coalition.” https://www.foodandlandusecoalition.org/. Accessed January 28, 2022.

GFDRR (Global Facility for Disaster Reduction and Recovery). n.d. “About Us.” https://www.gfdrr.org/en. Accessed January 28, 2022.

GGCP (Conservation International’s Green-Gray Community of Practice). n.d. “Global Green-Gray Community of Practice.” https://www.conservation.org/projects/global-green-gray-community-of-practice. Accessed January 28, 2022.

Government of Malawi. 2020. Malawi’s National Adaptation Plan Framework. Lilongwe, Malawi: Government of Malawi. https://napglobalnetwork.org/wp-content/uploads/2020/03/napgn-en-2020-malawis-national-adaptation-plan-framework.pdf.

Government of Malawi. 2021. Updated Nationally Determined Contributions. Lilongwe, Malawi: Government of Malawi. https://www4.unfccc.int/sites/ndcstaging/PublishedDocuments/Malawi%20First/Malawi%20Updated%20NDC%20July%202021%20submitted.pdf.

GPFLR (Global Partnership on Forest and Landscape Restoration). n.d. “About Us.” https://www.forestlandscaperestoration.org/. Accessed January 28, 2022.

IFAD (International Fund for Agricultural Development). 2015. “Investing in Rural People in El Salvador.” Rome: IFAD. https://www.ifad.org/documents/38714170/39150184/Investing+in+rural+people+in+El+Salvador.pdf/843f27d4-4929-458a-94b0-45e9479dfe1a.

Igoe, M. 2019. “Can ‘Nature-Based Solutions’ Be More than a Buzzword?” Devex. https://www.preventionweb.net/news/can-nature-based-solutions-be-more-buzzword.

IISD (International Institute for Sustainable Development), Global Environment Facility, United Nations Industrial Development Organization, and MAVA Foundation. 2021. How Can Investment in Nature Close the Infrastructure Gap? An Estimate of How Much Nature-Based Infrastructure Can Save Costs and Create Value Relative to Traditional Grey Infrastructure. https://nbi.iisd.org/wp-content/uploads/2021/10/investment-in-nature-close-infrastructure-gap.pdf.

Imbach, A., and A. Vidal. 2019. How Inter-institutional Networks Transform Landscapes: Lessons from Latin America on Advancing Forest Landscape Restoration. Gland, Switzerland: IUCN. xii + 94pp. https://doi.org/10.2305/IUCN.CH.2019.12.en.

Initiative 20x20. 2019. “Declaración por la Restauración.” https://initiative20x20.org/sites/default/files/inline-files/Declaraci%C3%B3n%20evento%20restauraci%C3%B3n%20COP25_pub%20web.pdf.

Initiative 20x20. 2021. “Comunicado Ministerial de la Iniciativa 20x20 del 2021.” https://initiative20x20.org/es/news/comunicado-ministerial-de-la-iniciativa-20x20-del-2021.

IPCC (Intergovernmental Panel on Climate Change). 2014. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II, and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. [Core writing team: R.K. Pachauri and L.A. Meyer (eds.)]. Geneva: IPCC. https://www.ipcc.ch/site/assets/uploads/2018/02/SYR_AR5_FINAL_full.pdf.

IPCC. 2018. “Annex I: Glossary,” edited by J.B.R. Matthews. In Global Warming of 1.5°C. An IPCC Special Report on the Impacts of Global Warming of 1.5°C above Pre-industrial Levels and Related Global Greenhouse Gas Emission Pathways, in the Context of Strengthening the Global Response to the Threat of Climate Change, Sustainable Development, and Efforts to Eradicate Poverty. Edited by V. Masson-Delmotte, P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, et al. Geneva: IPCC.  

IPCC. 2021. Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Edited by V. Masson-Delmotte, P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, et al. Cambridge: Cambridge University Press. In Press.

IUCN (International Union for Conservation of Nature). n.d. “Nature-Based Solutions.” https://www.iucn.org/theme/nature-based-solutions. Accessed January 26, 2022.

IUCN. 2020. “The Bonn Challenge.” https://www.bonnchallenge.org/.

Jirón Zavala, A. 2021. “Análisis de políticas orientadas a la adaptación al cambio climático en países de centroamérica.” CGIAR Research Program on Climate Change, Agriculture and Food Security. https://cgspace.cgiar.org/handle/10568/111196.

Kapos, V., S. Wicander, T. Salvaterra, K. Dawkins, and C. Hicks. 2019. The Role of the Natural Environment in Adaptation. Background paper for the Global Commission on Adaptation. Rotterdam and Washington, DC: Global Commission on Adaptation. https://files.wri.org/s3fs-public/uploads/Role_of_Natural_Environment_in_Adaptation_Paper_-_Global_Commission_on_Adaptation.pdf.

LAWFP (Latin American Water Funds Partnership). n.d. “The Latin American Water Funds.” https://www.fondosdeagua.org/en/. Accessed January 28, 2022.

Ledwell, C. 2019. Deep Roots for Resilient Communities: A Nature-Based Solution Helping Fiji Adapt to Climate Change. NAP Global Network. https://napglobalnetwork.org/stories/deep-roots-for-community-resilience-a-nature-based-solution-helping-fiji-adapt-to-climate-change/.

MARN (Ministerio de Medio Ambiente y Recursos Naturales, El Salvador; Ministry of the Environment and Natural Resources, El Salvador). 2018. Estrategia de restauración de ecosistemas y paisajes de El Salvador (2018–2023). San Salvador: MARN.

MARN. 2021. “Ministro López destaca avances en reforestación y restauración de ecosistemas durante reunión con países de la región.” San Salvador: MARN.

Mfitumukiza, D., A.S. Roy, B. Simane, A. Hammill, M.F. Rahman, and S. Huq. 2020. Local Action and Community-Based Adaptation. Background report for the Locally Led Action Track. Rotterdam and Groningen, Netherlands: Global Commission on Adaptation.

Nature4Cities. n.d. “Home.” https://www.nature4cities.eu/. Accessed January 28, 2022.

Naturvation. n.d. “Home.” https://www.naturvation.eu/. Accessed January 28, 2022.

NDC Partnership. n.d. “About Us.” https://ndcpartnership.org/. Accessed January 28, 2022.

ND-GAIN (Notre Dame–Global Adaptation Initiative). 2019. “El Salvador.” Notre Dame, IN: University of Notre Dame. https://gain-new.crc.nd.edu/country/el-salvador.

Ngwira, S., and T. Watanabe. 2019. “An Analysis of the Causes of Deforestation in Malawi: A Case of Mwazisi.” Land 8 (3): 48. https://doi.org/10.3390/land8030048.

OECD (Organisation for Economic Co-operation and Development). 2020. Nature-Based Solutions for Adapting to Water-Related Climate Risks. Environment Policy Papers Vol. 21. Paris: OECD. doi:10.1787/2257873d-en.  

Pacillo, G., B. Carneiro, G. Resce, G. Ruscica, A. Craparo, A. Basel, J. Ramirez-Villegas, et al. 2021. Assessing the Relationship between Climate, Food Security and Conflict in Ethiopia and in the Central American Dry Corridor (CADC). Quantitative Analysis on the Impact of Climate Variability on Conflict in Ethiopia and in the CADC Countries. Montpellier, France: CGIAR. https://hdl.handle.net/10568/116292.

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Pepinster, S. 2021. Nature-Based Solutions and Their Socio-economic Benefits for Europe’s Recovery. Brussels and London: Institute for European Environmental Policy.  

Rahaman, S., S. Jahangir, S. Haque, R. Chen, and P. Kumar. 2021. “Spatio-temporal Changes of Green Spaces and Their Impact on Urban Environment of Mumbai, India.” Environment, Development and Sustainability 23. https://link.springer.com/article/10.1007/s10668-020-00882-z.

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1. 1For example, reforestation in a region that is not experiencing any negative effects of climate change is not an NBS for adaptation measure even if the forests are helping to sequester carbon as part of climate mitigation efforts. Similarly, establishing urban green areas in a city for people’s enjoyment is not NBS for adaptation unless these green areas help reduce the effects of heat waves, rising temperatures, urban flooding, or other threats resulting from climate change. The climate risk must be present or projected, and the NBS activity must be expected to play a role in reducing this risk for it to be considered NBS for adaptation.
2. 2As part of the effort to reduce bias, authors also visualized results of only Cities4Forests and compared these results with a graph of the other initiatives. Since the top results remained the same or very similar when comparing this initiative with the rest, it seemed safe to proceed with allotting each initiative the same weight of “one point,” or “one voice.”
3. 3Learn more at Initiative 20x20’s website: https://initiative20x20.org/
4. 4Find the latest Initiative 20x20 factsheet here: https://initiative20x20.org/restoring-latin-americas-landscapes..
5. 5Guatemala allocates a preset percentage of its yearly budget, and Costa Rica funds its payment for ecosystem services program through fuel taxes.
6. 6Learn more at Cities4Forests’ website: https://www.wri.org/our-work/project/cities4forests.
7. 7Find the latest list of Cities4Forests member cities here: https://www.wri.org/our-work/project/cities4forests.

The authors are grateful to the Gordon and Betty Moore Foundation for providing the financial support that funded this research. The authors would like to thank all the survey respondents and interviewees who provided rich information for the results and discussion presented in this paper. We are grateful to our 18 internal and external peer reviewers: Anna Amato, James Anderson, Kathleen Buckingham, Tamara Coger, Ayesha Dinshaw, Maria Franco Chuaire, Jennifer Kane, Rob McDonald, Alex Mauroner, Teodyl Nkuintchua, Ryan O'Connor, Emmie Oliver, Saúl Pereyra, Samantha Power, Katie Reytar, Amit Singh, Siddharth Thyagarajan, and René Zamora-Cristales.

We also acknowledge the research support provided by Jonathan Cook, Kathleen Buckingham, Bradley Kratzer, Emma Illick-Frank, Melaina Dyck, Basit Muhammadi, and Abhinand Krishnashankar. Likewise, we appreciate the support from the project’s Steering Committee, including Carter Brandon, Cristina Rumbaitis del Rio, Rod Taylor, Sean DeWitt, Todd Gartner, and the Alliance for Global Water Adaptation team: Alex Mauroner, Eugenio Barrios, John Matthews, and Kari Davis.

We would also like to deeply thank Rebecca Carter for her tireless and continuous guidance during the yearlong process of research, writing, and revisions.

Stefanie Tye is a research associate with the Climate Resilience Practice at WRI. She works on a range of projects, including transformative adaptation in the agriculture sector, mainstreaming adaptation, locally led adaptation, and providing countries with technical assistance and policy recommendations on strengthening climate resilience.

Contact: stefanie.tye@wri.org

John-Rob Pool is the implementation manager of Cities4Forests at WRI. He works to cultivate awareness and spur action on the part of city governments and urban residents about the role that nature-based solutions can play in building cities’ resilience to climate change and in improving the lives of city residents.

Contact: john-rob.pool@wri.org

Luciana Gallardo Lomeli is a research associate with the Global Restoration Initiative at WRI. She works for Initiative 20x20, which aims to bring 20 million hectares of degraded land in Latin America into restoration by 2020, and serves as the team’s coordinator of projects in Mexico and Central American countries.

Contact: luciana.gallardo@wri.org

Whilst this paper is a product of an independent project funded by the Gordon and Betty Moore Foundation, the research was conducted in partnership with three NBS initiatives in which WRI plays a convening role: AFR100, Cities4Forests and Initiative 20x20.

AFR100

AFR100 is a country-led effort to bring 100 million hectares of land in Africa into restoration by 2030. It aims to accelerate forest and landscape restoration across Africa to enhance food security, increase climate change resilience and mitigation, and combat rural poverty. AFR100 is a partnership of 32 African governments and numerous technical and financial partners.

Cities4Forests

Cities4Forests is a global network of more than 80 cities committed to conserving, restoring, and sustainably managing trees, forests, and other nature-based solutions for human well-being. Cities4Forests supports cities’ efforts on their inner forests (such as urban parks and greenways), nearby forests (such as watersheds), and faraway forests (especially tropical forests) by raising awareness of the benefits of forests, inspiring political action and engagement, providing technical assistance, and facilitating economic analysis, finance, and investment.

Initiative 20x20

Initiative 20x20 is a country-led effort that aims to change the dynamics of land degradation in Latin America and the Caribbean by protecting and restoring 50 million hectares of forests, farms, pasture, and other landscapes by 2030. Through Initiative 20x20, 18 Latin American and Caribbean countries and three regional programs have committed to protect and/or restore more than 52 million hectares of land. The initiative is supported by more than 85 technical organizations and institutions and a coalition of impact investors and funds.

World Resources Institute is a global research organization that turns big ideas into action at the nexus of environment, economic opportunity, and human well-being.

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