Role of tropical wetlands for adaptation and mitigation
Tropical wetlands are vital for both adaptation and mitigation
Tropical wetland ecosystems such as peatlands and mangroves play an important role in mitigating climate change. Recent studies show that the ecosystem carbon pools of tropical peatlands and mangroves are over twice of the amount of upland tropical and temperate forests. What gives particular importance to these ecosystems is the fact that a great proportion of the C stocks are stored in belowground organic-rich soils, which can constitute significant sources of greenhouse gases if disturbed.
Tropical wetlands are important for adaptation as well. Peatlands regulate the timing and quantity of water flows (e.g. they gradually release stored water during droughts), and provide livelihood goods such fuel wood, timber, bark, and resins.
Mangrove ecosystems provide a wealth of ecosystem services important for adaptation and development such as protection of settlements and agriculture from tropical storms, floods, erosion and salt water intrusion, processing of waste and nutrient pollution, provision of nurseries and habitat for fish and crustaceans, and many wood and non-wood products. These ecosystem services are vital for the income, subsistence and protection of coastal communities, and for coastal sectors such as tourism, fisheries and energy.
Tidal and freshwater wetlands are highly vulnerable to anthropogenic and development pressures (e.g. palm oil production and intensive aquaculture), and to a range of climatic pressures such as temperature shifts, sea-level rise, droughts, floods and changes in seasonality. Societies living in and around wetlands are also becoming more and more vulnerable to climate vagaries, as the ecosystem services that they depend on are progressively being degraded.
Estimating carbon stock. Photo by Daniel Murdiyarso/CIFOR
Mitigation strategies can facilitate the adaptation of wetland ecosystems to climate change by enhancing their resilience through the reduction of anthropogenic pressures and the conservation of biodiversity. However, mitigation strategies should include additional adaptation measures to reduce the negative impacts of climate change on wetland ecosystems, as climatic pressures can hinder carbon sequestration services or even induce GHG emissions (e.g. fire in peatlands or mangrove die-back due to sea-level rise).
Adaptation measures can affect C-stocks positively, by either increasing or maintaining them and adaptation initiatives can benefit from financial incentives offered by mitigation mechanisms. For example, mangroves simultaneously contribute to protecting coastal areas and to storing carbon. Financial streams from carbon credits could help in ensuring the necessary funding that communities and local institutions need to conserve these mangrove ecosystems, which play a critical role for the safety of settlements, food security and livelihoods. However, there may be trade-offs between carbon and local ecosystem services prioritized by communities or institutions and more research is needed to understand where and when such trade-offs might occur.
Mitigation initiatives should also take into consideration the social dimensions of vulnerability as mitigation projects can have a significant impact on local livelihoods and the adaptive capacity of communities. The conservation of wetland ecosystems for mitigation purposes can result in better provision of ecosystem services, diversified incomes, infrastructure or social services but it can also result in the exclusion of local communities from the ecosystem services that they depend on, thus increasing their vulnerability to climate change.
A synergistic approach between adaptation and mitigation could be facilitated by international and national incentive mechanisms for mitigation action which integrate adaptation measures. Standards could be applied that evaluate the impacts of mitigation projects on community vulnerability and well-being. Ultimately, it is essential to foster knowledge sharing between adaptation and mitigation scientists, decision-makers and practitioners.