Ecosystem-based adaptation

Healthy ecosystems provide important ecosystem services that can contribute to climate change adaptation. For example, healthy mangrove ecosystems provide protection from the impacts of climate change, often for some of the world's most vulnerable people, by absorbing wave energy and storm surges, adapting to rising sea levels, and stabilizing shorelines from erosion. EbA focuses on benefits that humans derive from biodiversity and ecosystem services and how these benefits can be used for managing risk to climate change impacts. Adaptation to climate change is particularly urgent in developing countries and many Small Island Developing States that are already experiencing some of the most severe impacts of climate change, have economies that are highly sensitive to disruptions, and that have lower adaptive capacity.

EbA can involve a wide range of ecosystem management activities that aim to reduce the vulnerability of people to climate change hazards (such as rising sea levels, changing rainfall patterns, and stronger storms) through using nature. For example, EbA measures include coastal habitat restoration in ecosystems such as; coral reefs, mangrove forests, and marshes to protect communities and infrastructure from storm surges; agroforestry to increase resilience of crops to droughts or excessive rainfall; integrated water resource management to cope with consecutive dry days and change in rainfall patterns; and sustainable forest management interventions to stabilise slopes, prevent landslides, and regulate water flow to prevent flash flooding (see Table 1 and Figure 2).

By deploying EbA, proponents cite that many other benefits to people and nature are delivered simultaneously. These correlated benefits include improved human health, socioeconomic development, food security and water security, disaster risk reduction, carbon sequestration, and biodiversity conservation. For example, restoration of ecosystems such as forests and coastal wetlands can contribute to food security and enhance livelihoods through the collection of non-timber forest products, maintain watershed functionality, and sequester carbon to mitigate global warming. Restoration of mangrove ecosystems can help increase food and livelihood security by supporting fisheries, and reduce disaster risk by decreasing wave height and strength during hurricanes and storms.

Particular ecosystems can provide a variety of specific climate change adaptation benefits (or services). The most suitable EbA measures will depend on local context, the health of the ecosystem and the primary climate change hazard that needs to be addressed. The below table provides an overview of these factors, common EbA measures and intended outcomes.

Since the evolution of the concept and practice of EBA, various principles and standards have been developed to guide best practices for implementation.[6][7] The guidelines adopted by the CBD build on these efforts and include a set of principles to guide planning and implementation.[8] The principles are broadly clustered into four themes:

1. Building resilience and enhancing adaptive capacity through EBA interventions;
2. Ensuring inclusivity and equity in planning and implementation;
3. Consideration of multiple spatial and temporal scales in the design of EBA interventions;
4. Improving the effectiveness and efficiency of EBA, for example, by incorporating adaptive management, identifying limitations and trade-offs, integrating the knowledge of indigenous peoples and local communities.

These principles are complemented by safeguards, which are social and environmental measures to avoid unintended consequences of EBA to people, ecosystems and biodiversity.

Standards have also been developed to help practitioners understand what interventions qualify as EBA, including the elements of helping people adapt to climate change, making active use of biodiversity and ecosystem services, and being part of an overall adaptation strategy.[7]

The Paris Agreement explicitly recognises nature's role in helping people and societies address climate change, calling on all Parties to acknowledge "the importance of ensuring the integrity of all ecosystems, including oceans, and the protection of biodiversity, recognised by some cultures as Mother Earth"; its Articles include several references to ecosystems, natural resources and forests.

This notion has translated into high-level national intent, as revealed by comparative analyses of the Nationally Determined Contributions (NDCs) submitted to the UN Framework Convention on Climate Change (UNFCCC) by signatories of the Paris Agreement.[13][14][15] The UNFCCC also established the national adaptation plan (NAP) process as a way to facilitate adaptation planning in least developed countries (LDCs) and other developing countries. Because of their lower level of development, climate change risks magnify development challenges for LDCs.

Measures and interventions applied as part of EbA are often closely linked or similar to those employed under ecosystem-based disaster risk reduction (Eco-DRR). The Sendai Framework for Disaster Risk Reduction acknowledges that in order to strengthen disaster risk governance and manage disaster risk and risk reduction at global and regional levels, it is important "to promote transboundary cooperation to enable policy and planning for the implementation of ecosystem-based approaches with regard to shared resources, such as within river basins and along coastlines, to build resilience and reduce disaster risk, including epidemic and displacement risk".

The Sustainable Development Goals (SDGs) are a collection of 17 global goals set by the United Nations General Assembly in 2015. Biodiversity and ecosystems feature prominently across many of the SDGs and associated targets. They contribute directly to human well-being and development priorities. Biodiversity is at the centre of many economic activities, particularly those related to crop and livestock agriculture, forestry, and fisheries. Globally, nearly half of the human population is directly dependent on natural resources for its livelihood, and many of the most vulnerable people depend directly on biodiversity to fulfil their daily subsistence needs.[16] Ecosystem-based Adaptation offers potential to contribute towards the implementation of numerous SDGs, including the goals related to climate adaptation (SDG 13), eliminating poverty and hunger (SDGs 1 and 2), ensuring livelihoods and economic growth (SDG 8) and life on land and life under water (SDGs 14 and 15), among others.

The Strategic Plan for Biodiversity 2011-2020 and the Aichi Biodiversity Targets, under the Convention on Biological Diversity (CBD), aim to halt the loss of biodiversity to ensure ecosystems are resilient and continue to provide essential services. Most recently, the Conference of the Parties has adopted voluntary guidelines for the design and effective implementation of ecosystem-based approaches to adaptation and disaster risk reduction.[8]

EbA and similar approaches have been called for in other policy frameworks, including the United Nations Convention to Combat Desertification (UNCCD) and the Ramsar Convention.