Why Restoring Wetlands Is One of the Smartest Climate Investments We Can Make

Wetlands have had a rough few centuries. Drained for farming, filled in for housing, and straightened into canals, they were long seen as wasteland to be improved. Only in recent decades have we begun to understand how much we lost. Far from being useless, wetlands are among the most productive and valuable ecosystems on the planet — and restoring them is one of the most cost-effective things we can do for both climate and wildlife.

At their simplest, wetlands are areas where water covers the soil, either permanently or seasonally. That includes marshes, swamps, bogs, fens, and floodplains. Each type behaves differently, but they share a set of remarkable properties. They slow water down, filter it, and hold it. They teem with life. And crucially, they lock away carbon in their waterlogged soils, sometimes for thousands of years.

Carbon, floods, and wildlife

The carbon storage is the headline. When plants die in a wetland, the waterlogged conditions slow decomposition dramatically. Instead of rotting and releasing carbon back into the atmosphere, dead plant matter accumulates as peat. Over time, this builds up into deep stores of carbon. When a wetland is drained, that process reverses — the peat dries out, oxygen gets in, and the carbon is released. Draining a wetland can turn a carbon sink into a carbon source.

Flood defence is the second big benefit. A healthy wetland acts like a sponge. When heavy rain falls, it absorbs water and releases it slowly, reducing the peak flow that reaches rivers and drains. Restoring floodplains upstream can protect towns downstream far more cheaply than building ever-higher concrete walls. It also creates space for water to spread out rather than being channelled into a narrow, fast-moving channel.

Then there is the wildlife. Wetlands are nurseries for fish, breeding grounds for birds, and home to a huge range of insects, amphibians, and plants. Many species that have declined sharply in recent decades — wading birds, dragonflies, amphibians — depend on these habitats. Restoring a wetland can bring back a surprising amount of life surprisingly quickly.

They also do quieter work. Wetlands filter pollutants out of water, trapping sediment and nutrients before they reach rivers and lakes. They recharge groundwater. They cool the surrounding landscape through evaporation. In cities, they can be designed into parks and green spaces, managing stormwater while giving people somewhere pleasant to walk.

What restoration actually involves

Restoring a wetland is not simply a matter of flooding a field and hoping for the best. It usually starts with reconnecting a river to its floodplain, removing drainage ditches, or blocking the channels that carry water away. Sometimes it means reintroducing the plants and animals that once lived there. Often it means working with farmers and landowners, because the land has been used for something else for generations.

It also takes patience. A restored wetland will not look like a pristine one overnight. It may take years for peat to form and for specialist species to return. But the trajectory is usually positive, and the benefits — flood protection, water quality, wildlife, carbon — start accruing long before the ecosystem is fully mature.

The case for wetlands is not just ecological. It is practical. They are cheaper than concrete, they get better over time rather than wearing out, and they provide benefits that engineered solutions simply cannot. If we are serious about climate resilience and biodiversity, restoring wetlands should be near the top of the list.