Ecosystem-based Adaptation and Mitigation
The effects of climate change are recognized globally and are likely to increase in the future. Sea-level rise and increased storm intensity severely affect coastal communities, whereas rising water temperatures, changes in species distribution and change coastal and oceanic ecosystems dramatically.
Healthy, well-functioning ecosystems enhance natural resilience to the adverse impacts of climate change and reduce the vulnerability of people. Ecosystem-based management offers a valuable approach for climate change adaptation, complementing traditional actions such as infrastructure development. This approach, known as “Ecosystem-based Adaptation” (EbA), uses biodiversity and ecosystem services as part of an overall adaptation strategy to help people and communities adapt to the negative effects of climate change at local, national, regional and global levels. Coastal EbA measures include managing mangrove forests and other coastal habitats to protect communities from storms and flooding. Those natural buffers are often cheaper and more effective than technical solutions and physical engineered structures.
In addition to protection from climate change impacts, EbA also provides many other benefits to communities, for example through the maintenance and enhancement of ecosystem services crucial for livelihoods and human well-being, such as clean water and food. Appropriately designed ecosystem management initiatives can also contribute to by avoiding emissions derived from habitat loss, and enhancing carbon sequestration.
Corals, calcareous phytoplankton, mussels, snails, sea urchins and other marine organisms use calcium and carbonate in seawater to construct their shells or skeletons. As the acidity of seawater increases due to rising levels of CO2 in the ocean, carbonate becomes less available and limits the organisms’ ability to form their skeletal material.
Ocean acidification is having major impacts on reef building corals. It is already slowing hard corals’ growth rates. Left unchecked, coral reefs will soon stop growing and erode away. Their disappearance would cost society billions of dollars annually due to losses in fishing, tourism and coastal protection services. Many commercial fisheries depend on reefs which provide food and shelter for fish, and the loss of reefs may further destabilize already depressed commercial fish populations.
Ocean acidification furthermore has direct impacts on some important plankton species and sensitive larval stages of many marine organisms and could cause major ripple effects throughout ecosystems and food webs, ultimately affecting even the largest animals in the oceans as well as many commercial fisheries. Ocean acidification adds another layer of stress onto already impacted coastal and marine ecosystems.