Congo Basin forest elephants, for example, eat and expel seeds from trees that are particularly good at storing carbon.
Forests, oceans and wetlands are formidable carbon sinks helping to limit global warming, but several types of animals could also play a key role. Animal species, by trampling the ground, eating plants or other animals or through their excrement, contribute to facilitating carbon capture, according to a study published Monday, March 27 in the journal Nature Climate Change.
The preservation or restoration of just nine of these species – marine fish, whales, sharks, gray wolves, wildebeest, sea otters, musk oxen, African forest elephants and American bison – could thus allow the capture of 6.41 gigatonnes of carbon dioxide per year, estimates the study signed by fifteen scientists from eight countries.
Together with all other emission reduction measures, this would represent more than 95% of the annual amount needed to meet the goal, by 2100, of removing 500 gigatonnes of carbon from the atmosphere. This objective would keep global warming below the threshold of 1.5°C compared to the pre-industrial era.
“Many species could exert a very strong control over the carbon cycle by causing differences of 15 to 250% in the amounts of CO2 absorbed and stored in plants and soils, compared to conditions where animals are absent. “
Oswald Schmitz, Yale professor and lead author of the studyat AFP
Elephants in the Congo Basin forest, for example, eat and expel seeds from trees that are particularly good at storing carbon and promote their germination in their droppings. They also trample understory vegetation to make way for tall trees – those that store the most carbon. Their restoration could lead to an additional annual storage of 13 million tons of carbon, scientists estimate. Their number has fallen by 86% over the past 31 years. Conversely, their extinction would lead to a loss of 7% of carbon storage, or 3 billion tonnes in total. The largest contributors to carbon storage would be fish, with 5.5 gigatonnes per year alone.