Freshwater wetlands cover less than 5% of the world’s land area, but store vast quantities of carbon per hectare in the form of peat soils. Protecting peatlands and rewetting drained peatlands can prevent massive carbon emissions, reduce destructive peat fires, and improve water quality.
Protection and restoration of coastal ecosystems (mangroves, salt marshes and seagrass beds—or ‘blue carbon’) has a relatively low global mitigation potential due to its small distribution but these ecosystems can store carbon at high rates per hectare. They often also provide significant benefits to society: supporting ocean fisheries, protecting coasts, tourism and filtering run-off and pollution that can be worth many thousands of dollars per hectare per year.
The greatest cost-effective emissions reduction potential in the wetlands biome was found to be through avoided peatland impacts—the protection of marshes and peat bogs are a more effective long-term carbon store than forests. It is estimated that 760,000 hectares of peatlands are lost globally each year, the majority being cleared and drained for palm oil developments. Their cost-effective protection could prevent 678 million tonnes of carbon emissions a year by 2030—comparable to removing 145 million cars from the streets.