Protecting or expanding the populations of nine key groups of animals, including wolves and whales, would remove huge amounts of carbon from the atmosphere.
Restoring the populations of a few important groups of animals could help capture huge amounts of carbon from the air and thereby play a role in limiting global warming.
Climate change research has emphasised the importance of vast forests and seagrass meadows as the most efficient way of storing carbon. But bison, elephants, whales, sharks and other massive wild animals also store carbon in their bodies while promoting tree and seagrass growth, preventing carbon-releasing wildfires and packing down ice and soil to keep carbon in the ground, says Oswald Schmitz at Yale University.
“There’s been scepticism in the scientific community that animals matter, because if you just do the accounting, they’d say animals don’t make up much of the carbon on the planet, so they can’t be important,” he says. “What we’re doing is connecting the dots, showing that animals – despite their lack of abundance – have an outsized role, because of the multiplier effects that they create.”
To keep the average global temperature from rising more than 1.5°C above its pre-industrial level, scientists estimate that we need to remove 6.5 gigatonnes of carbon dioxide per year from the atmosphere until 2100. Current models that focus on protecting and restoring forest, wetland, coastal and grassland ecosystems would fall short by an estimated 0.5 to 1.5 gigatonnes per year, says Schmitz.
He and his colleagues reviewed data from previous publications about the environmental effects – including dispersing seeds, trampling, carbon cycling, feeding behaviour, hunting behaviour and methane production – of dozens of kinds of wild animals.