Our trees in Madagascar

Along the fringes of coasts, where land and ocean meet, lie the world’s salt marshes, mangroves, and sea grasses. These coastal wetland ecosystems are found on every continent except Antarctica.

They provide nurseries for fish, feeding grounds for migratory birds, a first line of defence against storm surges and floodwaters, and natural filtration systems that boost water quality and recharge aquifers. Relative to their land area, they also sequester huge amounts of carbon in plants aboveground and in roots and soils below.

Coastal wetlands can store five times as much carbon as tropical forests over the long term, mostly in deep wetland soils. The soil of mangrove forests alone may hold the equivalent of more than two years of global emissions—22 billion tons of carbon, much of which would escape if these ecosystems were lost.