Restoring wetlands to achieve climate goals
Environmentalists are warning New Zealand needs to save its wetlands to achieve its climate goals. They say peat wetlands are more powerful than tropical forests at absorbing carbon, and our Government needs to devise a plan to protect and recharge them.
“Only about 10 percent of our historic wetlands remain, and the few wetlands left are dwindling every day to make room for pasture or urban development,” says Forest & Bird freshwater advocate Annabeth Cohen.
Picture credit - ramsar.org
“Peat wetlands in particular are super carbon sinks. They hold twice as much carbon as all of the world’s forests combined, yet cover only about 3% of earth’s land surface.
“The majority of the drained peatland in Aotearoa is used for intensive farming. Dried peatland emits carbon and is responsible for up to 6% of agricultural emissions in New Zealand.”
Cohen says wetlands must be wet for them to work, and she calculates the country could save as much as two million tonnes of carbon dioxide every year if we re-wet the peat.
Large amounts of carbon, fixed from the atmosphere into plant tissues through photosynthesis, are locked away in peat soils, representing a valuable global carbon store. Image credit - International Union for Conservation of Nature.
“Research shows peat wetlands have a net cooling effect in the long term. They absorb huge amounts of carbon, which is a long-lasting greenhouse gas, and permanently store it away.”
“Coastal wetlands such as mangroves, salt marshes, and sea grasses are also excellent at sequestering carbon, known as blue carbon. On average, they can trap carbon 35-57 times faster than tropical forests.
“We know wetlands are good at attracting and feeding our birdlife, provide excellent nurseries for our endangered native fish, clean and filter our water, and are the most cost-effective solution to flood and drought protection.”
Hannahs Bay, Rotorua. Image credit -National Wetland Trust.
With such a long list of wetland benefits she says Forest & Bird are calling on the Government to develop a national restoration plan. “We have a goal for swimmable rivers, so where is the ambitious goal for our climate-protecting, lifesaving wetlands?”
Karen Denyer from National Wetland Trust says growing crops on wet soils is one opportunity for expanding our wetlands.
"Re-wetting peatland and growing wet-tolerant crops is already gaining traction overseas. Tangata whenua have a long history of sustainably harvesting from wetlands, so there’s a lot of traditional knowledge to guide us. Imagine if Aotearoa could rewet a portion of its peatlands, and grow species such as raupō or harakeke for high-end, eco-friendly products. It's a win-win for land owners and the climate," says Denyer.