Ecosystem-based Adaptation (EbA)
People worldwide depend on intact ecosystems and the services they provide, such as soil fertility, clean water and food. This is especially true for poor people in developing countries, whose livelihoods are closely linked to natural resources. In the Millennium Ecosystem Assessment 2005, it was emphasized that climate change constitutes one of the major causes of changes and deterioration in ecosystem services and its impact will most likely increase in the future. At the same time, functioning ecosystems help people and the natural world adapt to climate change effects.
The most common definition of EbA is provided by the Convention of Biological Diversity (CBD): “Ecosystem-based adaptation (EbA) is the use of biodiversity and ecosystem services as part of an overall adaptation strategy to help people to adapt to the adverse effects of climate change”.
Ecosystem services are the benefits humans receive from ecosystems. These benefits can be categorized as the following:
provisioning services: food, fresh water, raw materials and medicinal resources
regulating services: regulation of climate, floods, diseases, water quality and waste management
cultural services: facilitation of spiritual fulfillment, aesthetic appreciation and eco-tourism
supporting services: soil formation, photosynthesis, nutrient cycle
EbA thus acknowledges that healthy ecosystems play a fundamental role in sustaining and improving the resilience of both the ecosystems in themselves and the people who live within them against climate change and the risks related to it. In sum, what defines an EbA project is that it always aims to reduce people’s vulnerability to and increase their resilience against climate change by actively making use of biodiversity and ecosystem services. An EbA project will furthermore integrate well into and support as well as enhance national, regional and local climate change policy.
Ecosystem-based Adaptation conceptualized in
the Driving Forces-Pressures-State-Impacts-Responses (DPSIR) framework
With the Millennium Ecosystem Assessment in 2005, Ecosystem-based Adaptation gained further relevance and support among policy-makers and practitioners working with adaptation and development. After multiple years of discussions on definitions and conceptualizations, focus is now on providing information on implementation and funding opportunities for EbA measures. Another core aim is to strengthen the linkage between biodiversity/ecosystem services and climate change by improving and disseminating knowledge on this connection.
EbA demands a thorough understanding of ecosystem services and the processes needed to generate those. As the utilization of certain ecosystem services for adaptation purposes will for instance always entail that other such services cannot be used, a sensitive and knowledge-based prioritization needs to take place. For example, the preservation of mangrove forests as a protection against coastal erosion competes with the utilization of mangrove shrub and tree species as fire wood.
When discussing EbA, it is important to distinguish the following two concepts:
preservation and utilization of ecosystem services for human adaptation to climate change (EbA)
ecosystem management for ecosystem adaptation to climate change, with the primary goal of protecting ecosystem services (‘adaptation of ecosystems’)
Whilst the first adaptation category focuses on the resilience of human beings, the second conceptualization aims to generate nature protection.
Examples of EbA practices are for instance:
- coastal protection measures for the preservation or re-creation of mangroves and other coastal ecosystems, through which the impacts of floods, coastal erosion and salinization can be contained
- sustainable forest cultivation to stabilize the soil in hillside situations and to regulate water infiltration and runoff
- establishment of agroforestry-systems for the diversification of species and livelihood opportunities, the stabilization of the cultivation system as well as for the strengthening of resilience
- preservation of protected natural areas which feature a high biodiversity, in order to maintain genetic resources for agricultural crops and animals that have adapted to climate change
- management of invasive species, which harm the native biodiversity and threaten food- or water security
- water management e.g. in catchment areas
- urban EbA includes approaches based on the design and improvement of green and blue infrastructure, e.g. urban parks, green roofs and facades, tree planting, rivers, ponds, as well as other types of interventions that use ecosystem functions to provide forms of adaptation to climate risks, e.g. measures to increase soil permeability.
Eba is considered an adaptation approach with low or no implementation risk (‘no regrets’) – even if projected climatic changes do not occur, EbA measures create a variety of positive effects for people and the environment. EbA constitutes a widely applicable adaptation approach functioning on a variety of spatial and temporal scales. It holds the potential of providing more cost-effective and locally applicable solutions to climate change adaptation for relatively poor communities than engineered, costly solutions can bring about. EbA measures can, however, stand in competition with other forms of cultivation (for instance agriculture, stock breeding, wood production, gathering) (GIZ).