Flooding Wetlands Could Be the Next Big Carbon Capture Hack
Arriving at the tidal wetlands of Mungalla Station on the coastline of northern Queensland, ornithologist Simon Kennedy from the not-for-profit BirdLife Australia is greeted by a welcome cacophony. “You start hearing honks and quacks and twitters and noises coming from there,” he says of the area’s diverse and thriving bird populations, “whereas it’s very quiet elsewhere.”It wasn’t always this way. A decade or so ago, these saltwater wetlands—which cover around a quarter of the 880 hectares that make up Mungalla Station—were a mess of freshwater-sodden pastures, riddled with invasive weeds that were choking the land and waterways. The reason was an earth wall—known as a bund, built more than half a century ago where the estuary of the local river meets the sea—that blocked off incoming seawater to transform the saltwater wetlands into a ponded freshwater pasture for cattle farming. This created the perfect environment for invasive freshwater weeds and drove out much of the native wildlife. By transforming the composition of the land, it likely released a lot of carbon and methane, too.But in 1999 the Nywaigi—the local Aboriginal people and traditional owners of the land—purchased it. “When we got our country back, we inherited the bad farming practices,” says Jacob Cassady, a Nywaigi man and managing director of the Mungalla Aboriginal Business Corporation, which now owns the station.Working with scientists and environmental organizations, the Nywaigi people have since transformed Mungalla Station back into traditional saltwater wetlands, creating a haven for native plant and animal life—including huge saltwater crocodiles. This has drawn in birdwatchers and ecotourists, but has had more far-reaching consequences too: improving the health of the nearby Great Barrier Reef as well as capturing carbon, meaning the wetlands could be used in the future to offset emissions elsewhere.With the impacts of global warming becoming more severe every year, governments—including Australia’s—are waking up to the reality that significant climate action is needed, and that reducing greenhouse gas emissions alone isn’t going to be enough. Drawing carbon out of the air and locking it back into the landscape—what’s known as “carbon sequestration”—has to happen too.You can do this mechanically, but also through harnessing the processes of nature. Reforestation can lock carbon into the terrestrial landscape, creating “green” carbon stores, while regenerating the plants and wildlife of coastal ecosystems—such as estuaries, mangroves, and saltwater marshes—locks in carbon as well, creating “blue” carbon sinks. These have significant benefits.When in their natural state, coastal wetland environments like those at Mungalla store carbon for much longer and more efficiently than terrestrial ecosystems, and regenerating them also creates habitats for marine species that are a vital food source for many communities. Re-establishing environments such as mangroves can also serve as a buffer against storms and tsunamis. For the Nywaigi people, returning the wetlands to their original state has also allowed them to reconnect with lands that they share a historic bond with, while also boosting tourism and creating jobs.
The Nywaigi people in Australia have discovered a way to sequester carbon, boost coastal biodiversity, and create jobs.
Arriving at the tidal wetlands of Mungalla Station on the coastline of northern Queensland, ornithologist Simon Kennedy from the not-for-profit BirdLife Australia is greeted by a welcome cacophony. “You start hearing honks and quacks and twitters and noises coming from there,” he says of the area’s diverse and thriving bird populations, “whereas it’s very quiet elsewhere.”
It wasn’t always this way. A decade or so ago, these saltwater wetlands—which cover around a quarter of the 880 hectares that make up Mungalla Station—were a mess of freshwater-sodden pastures, riddled with invasive weeds that were choking the land and waterways. The reason was an earth wall—known as a bund, built more than half a century ago where the estuary of the local river meets the sea—that blocked off incoming seawater to transform the saltwater wetlands into a ponded freshwater pasture for cattle farming. This created the perfect environment for invasive freshwater weeds and drove out much of the native wildlife. By transforming the composition of the land, it likely released a lot of carbon and methane, too.
But in 1999 the Nywaigi—the local Aboriginal people and traditional owners of the land—purchased it. “When we got our country back, we inherited the bad farming practices,” says Jacob Cassady, a Nywaigi man and managing director of the Mungalla Aboriginal Business Corporation, which now owns the station.
Working with scientists and environmental organizations, the Nywaigi people have since transformed Mungalla Station back into traditional saltwater wetlands, creating a haven for native plant and animal life—including huge saltwater crocodiles. This has drawn in birdwatchers and ecotourists, but has had more far-reaching consequences too: improving the health of the nearby Great Barrier Reef as well as capturing carbon, meaning the wetlands could be used in the future to offset emissions elsewhere.
With the impacts of global warming becoming more severe every year, governments—including Australia’s—are waking up to the reality that significant climate action is needed, and that reducing greenhouse gas emissions alone isn’t going to be enough. Drawing carbon out of the air and locking it back into the landscape—what’s known as “carbon sequestration”—has to happen too.
You can do this mechanically, but also through harnessing the processes of nature. Reforestation can lock carbon into the terrestrial landscape, creating “green” carbon stores, while regenerating the plants and wildlife of coastal ecosystems—such as estuaries, mangroves, and saltwater marshes—locks in carbon as well, creating “blue” carbon sinks. These have significant benefits.
When in their natural state, coastal wetland environments like those at Mungalla store carbon for much longer and more efficiently than terrestrial ecosystems, and regenerating them also creates habitats for marine species that are a vital food source for many communities. Re-establishing environments such as mangroves can also serve as a buffer against storms and tsunamis. For the Nywaigi people, returning the wetlands to their original state has also allowed them to reconnect with lands that they share a historic bond with, while also boosting tourism and creating jobs.