Restoring just nine groups of animals could help combat global warming

Restoring populations of some important groups of animals can help capture large amounts of carbon from the atmosphere, thereby playing a role in limiting global warming.

Climate change research has emphasized the importance of extensive forests and seagrass meadows as the most efficient way to store carbon. But bison, elephants, whales, sharks and other giant wildlife also encourage the growth of trees and seagrass, prevent carbon-releasing wildfires, and pack ice and soil to keep carbon in the ground. And they store carbon in their bodies, says Oswald Schmitz of Yale University. .

“There is widespread skepticism in the scientific community that animals matter because, by simple math, they don’t make up much of the carbon on Earth, so they shouldn’t matter.” because they say,” he says. “What we’re doing is connecting the dots and showing that animals, despite their small numbers, play a very large role because of the multiplier effect they produce.”

Scientists estimate that by 2100, we will need to remove 6.5 gigatonnes of carbon dioxide from the atmosphere annually to keep the global average temperature from rising more than 1.5°C above pre-industrial levels. Wetland, coastal and grassland ecosystems are estimated to be short of 0.5 to 1.5 gigatonnes per year, Schmitz said.

He and his colleagues reviewed data from previous publications on the environmental impacts of dozens of species of wild animals, including seed dispersal, trampling, carbon cycling, feeding behavior, hunting behavior, and methanogenesis. .

They determined that by conserving six groups of animals and expanding three more, we could theoretically meet our global carbon reduction goals. Reef shark, gray wolf, wildebeest, sea otter, musk oxen and marine fish populations should be maintained at current levels. There must also be at least 500,000 African forest elephants, 2 million American bison and 188,000 baleen whales in the Antarctic. In total, these populations could help capture about 6.41 gigatonnes of carbon dioxide annually, Schmitz says.

Herbivores consume plants that compete with trees for resources, pack carbon-rich soil and permafrost ice, maintain grasslands that might otherwise lead to wildfires, and disperse seeds. Promote new tree growth through My body for decades.

Whales increase the population of phytoplankton, which absorb carbon at the surface through respiration and faeces, and when they die, they send large amounts of carbon deep into the ocean floor. Predators, on the other hand, control animal populations and, if left unchecked, can endanger carbon-storing plants on land and in the ocean.

With the right conditions, populations of these animals could recover quickly, Schmitz said, but large areas of farmland would need to be returned to nature.

“Instead of being a cattle rancher, think about being a carbon rancher,” he says. “Give back the bison and actually pay ranchers for the carbon they store instead of the meat their cows produce.”

The new findings “summarize a commendable broad vision of global rewilding” but do not provide enough evidence for policy recommendations, says Yadvinder Malhi of the University of Oxford.

“I think there really is potential for synergies between wildlife conservation and carbon sequestration. [but] I’m wary of something like this being touted as a ‘global warming game changer,'” Malhi said.

“The science is not yet robust enough, and given the urgency of the climate crisis, the timescales involved are often too late,” he says. “Trying to incorporate this into the international climate framework is even a distraction from the only true global warming game changer that is keeping fossil fuels in the ground.”