It started in 1937 as the International Wildfowl Inquiry - a few European ornithologists worried about declining duck numbers. The name kept changing as the mission widened. The International Waterfowl and Wetlands Research Bureau came next, then sister organizations in Asia and the Americas, and finally, in 1995, the three regional bodies merged into Wetlands International. The head office settled in Ede, in the agricultural heart of the Netherlands - the same flat green country that has spent a thousand years learning, sometimes the hard way, what happens when you mess with water. Today the organization works in over a hundred countries and runs about eighty projects, with field offices on every inhabited continent.

Peatlands occupy only about three percent of the world's land surface but hold roughly twice as much carbon as all the planet's forests combined. Drain a peatland and the dead plant matter that has been waterlogged for millennia starts to oxidize, and a quiet swamp becomes a fast carbon chimney. Wetlands International's project to rewet drained peatlands in Russia, run jointly with the Russian government and Greifswald University, was recognized by the UN climate body in 2017 for storing up to 200,000 tonnes of carbon dioxide equivalent every year - not by planting anything new, but by putting the water back. In Indonesian Borneo, on the burned and drained peatswamps of Central Kalimantan, the same logic plays out at hotter, smokier scale: small dams and blocks slow the drainage, native trees go back into the soil, community fire brigades patrol the dry season.

On the high Tibetan plateau, the Ruoergai marshes act as a giant sponge between the Himalayas and the Chinese lowlands, storing glacial meltwater that eventually feeds both the Yellow and Yangtze rivers. For years, peat was being mined out of the marsh and the drainage canals were widening. The Wetlands International China office spent years documenting the damage and lobbied to have Ruoergai designated a Ramsar site under the international treaty that requires signatory governments to protect their listed wetlands. The designation worked. Peat mining and drainage are now prohibited in Ruoergai and the neighboring counties. Two of Asia's greatest rivers got a slightly better deal because a few people kept making the same argument, in the right rooms, for long enough.

The same organization studying frozen Tibetan peat also works the other end of the climate spectrum. In Mali, on the Inner Niger Delta - one of the great seasonal wetlands of West Africa - the focus is livelihoods. Pastoralists, fishers, and rice farmers all depend on the river's annual flood, and a changing climate plus upstream dams have made that flood less reliable. On the world's coasts, mangrove forests do the work that concrete sea walls only pretend to do, and reefs blunt the energy of storms. Mangroves can even rise with the sea if given room to migrate inland. The trick - in Mali, in Bangladesh, in Senegal - is convincing governments and developers that the cheapest flood protection is the kind that grows roots.

The International Waterbird Census now spans over 25,000 sites in more than 100 countries and has been running for nearly sixty years. Outside North America - where the Audubon Christmas Bird Count covers similar ground - it is the largest continuous dataset on migratory waterbirds in the world. Tens of thousands of volunteers, most of them amateurs with binoculars and a clipboard, generate the numbers that researchers, treaty negotiators, and conservation planners use to argue for the protection of flyway sites. From the East Atlantic flyway through the Mediterranean, across the African-Eurasian routes, into the great Yellow Sea staging grounds where shorebirds refuel between the Arctic and Australia, each stop is a stepping stone, and each stone has to hold. Lose one and the migration breaks. Wetlands International, headquartered in a quiet Dutch town that most people drive past on the way to somewhere else, exists to make sure they don't.