Wetlands worth an estimated USD 47 trillion a year

Wetlands and coastal ecosystems will be a topic of discussion at Global Landscapes Forum Kyoto on 13 May. Here’s how to listen.

For Max Finlayson, an ecologist at Australia’s Charles Sturt University (CSU), wetlands have always been a place of solace.

“I grew up in a cheap state-housing area on the edge of a small town,” he describes. “So I used to escape to the wetlands. For me it was a way to get away from all the hum-drum social problems around me. I found succor, personal space and time, by going into the swamps… I began discovering the birds, the frogs and snakes; paying attention to plants, and different vegetation,”

Unfortunately, Finlayson’s soft spot for swamps is not yet shared as widely as he would hope. Wetlands have historically been viewed by many as unproductive wastelands, breeding grounds for mosquitoes that should be drained and developed.

Given how many wetlands have been destroyed and degraded, “what’s left is even more valuable,” says Finlayson, “but it’s under a lot of pressure.” That’s why he and his colleagues decided, in a new study out this month, to provide an updated approximation of the dollar value of the ecosystem services that wetlands provide across the globe, in a bid to argue more powerfully for their protection.

UNSUNG HEROES

The study builds on earlier estimates of these ecosystems’ worth, using new and better on wetland areas  around the world. The researchers found that wetlands make up between 40 and 45 percent of the value of all global ecosystems, contributing around USD 47 trillion per year in ecosystem services. The lion’s share of this value (68 percent for inland wetlands and 89 percent for coastal ones) comes from the regulating services that these ecosystems provide, such as maintaining water and soil quality through filtration and nutrient cycling, as well as protecting river banks and coastlines against flooding and erosion.

The study also showed that coastal wetlands in particular are punching above their weight: while they comprise only 15 percent of the global natural wetland area, the scientists estimate that they provide over 43 percent of the value of all wetland classes. Alongside peatlands, saltwater coastal wetlands can also sequester and store vast amounts of carbon dioxide, playing a crucial role in climate change mitigation. This means that efforts to protect and restore ecosystems such as Indonesia’s vast array of mangrove forests and seagrass meadows might be particularly important in the coming decades when global temperatures increase.

“Where we have them, the figures for wetland destruction are horrific,” says Finlayson. Across the globe, around 35 percent of the world’s wetlands were lost between 1970 and 2015, with annual rates of loss accelerating from 2000 onwards. Some in-country statistics are even more alarming: New Zealand, for example, has destroyed almost 90 percent of its natural wetlands, mostly within the last 150 years in the name of agricultural and urban development.

A PRICE ON NATURE?

Coming from a biological background, Finlayson says his first response to the idea of putting a dollar value on ecosystem services was one of ridiculousness. He’s the first to acknowledge that the data is not definitive and skips past the meaning that wetlands hold for many people.

It doesn’t take into account, for example, his own appreciation of wetland spaces as places for reflection and solace, or any other aesthetic, spiritual or totemic values that people might give to them. “So we do need to look very carefully at the values we’re using in the study,” he says, “because they’re just an indicator of worth, and [wetlands] will mean different things in different societies.”

Nevertheless, monetary evaluations can have particular impact in corridors of power. “Lots of people argue very strongly against such things – they call it the commodification of biodiversity,” says Finlayson. “But my colleagues and I thought, well, we say we value biodiversity, but then we’re destroying it at the same time. We’re still losing ecosystems and species. So what’s another way of showing their value, so that we can start turning things around?”

Restoration of wetland ecosystems is also important, and the just-announced UN Decade on Ecosystem Restoration may well channel extra energy toward this task. However, for Finlayson, the most effective step is to keep existing wetlands standing wherever possible. “If we take more away, we will quickly realize what we’ve lost,” says Finlayson. “But it will already be gone.”