Ecosystem services play an important role in the two broad strategies for tackling climate change: mitigation (reduction of emissions sources or enhancement of sinks of greenhouse gases) and adaptation (adjustment in natural or human systems to moderate harm or exploit beneficial opportunities from climate variations). Ecosystems contribute to mitigation because of their capacity to remove carbon from the atmosphere and to store it, a well-documented ecosystem service. For example, three main mitigation activities are possible in the forestry sector: afforestation (converting long-time non-forested land to forest); reforestation (converting recently non-forested land to forest); and avoided deforestation (avoiding the conversion of forests to non-forested land). Ecosystems contribute also to adaptation because they provide services that can help people adapt to both current climate hazards and future climate change. Although these “adaptation ecosystem services” are less documented than the “mitigation ecosystem service” (i.e, carbon), we can identify six cases in which ecosystems can support adaptation: (1) ecosystems providing goods to local communities facing climatic threats; (2) trees in agricultural fields regulating water, soil, and microclimate for more resilient production; (3) forested watersheds regulating water and protecting soils for reduced climate impacts; (4) ecosystems protecting coastal areas from climate-related threats; (5) urban forests and trees regulating temperature and water for resilient cities; (6) ecosystems regulating rainfall at the regional scale. While ecosystem services are part of the solution to climate change, they are also affected by changing climatic conditions. Ecosystem-based approaches to climate change should recognize that the linkages between ecosystem services and climate change are twofold: ecosystems for adaptation and mitigation (ecosystems contribute to adaptation and mitigation) and adaptation for ecosystems (as climate change will affect ecosystems and their services, adaptation measures are needed to reduce negative impacts and maintain ecosystem functions). Several policies have considered ecosystem-based approaches to adaptation and mitigation. Regarding mitigation, the greenhouse gas reduction targets and national accounting of industrialized countries in the Kyoto Protocol include carbon emissions and removals from ecosystems. Afforestation and reforestation projects in developing countries are eligible under the Clean Development Mechanism (CDM). Reducing emissions from deforestation and forest degradation (REDD+), an initiative now at the top of the international climate negotiation agenda, is based on financial incentives to preserve forests and thus maintain or increase carbon stocks. Regarding adaptation, several National Adaptation Programmes of Action (NAPAs) of Least Developed Countries recognize the role of ecosystem services in adaptation. Although adaptation and mitigation present notable differences, particularly in their objectives, spatial and temporal scales, there is an increasing interest in trying to pursue them jointly. Given that ecosystems can provide mitigation and adaptation services at the same time, policies and local initiatives related to ecosystem management have the potential to contribute to both climate change strategies and to avoid trade-offs between them. For example, mangroves simultaneously contribute to protecting coastal areas and to storing carbon. Mitigation projects can improve the adaptation of local livelihoods by increasing the provision of local ecosystem services to communities and diversifying incomes and economic activities. But impacts can be also negative, for example, if projects restrict the rights and access of local people to land and forest resources. Mitigation projects (such as REDD+) can also to facilitate ecological adaptation to climate change (e.g. by reducing anthropogenic pressures on forests, enhancing connectivity between forest areas and conserving biodiversity hotspots) but trade-offs have been also observed (e.g., monospecific forest plantations with low ecological resilience).