Animals May Play Significant Role in Carbon Cycling, Researchers Say

Wildlife may play a more important role in the global carbon cycle than researchers have previously given it credit for, according to a study from an international group of scientists. Although models generally include carbon cycling by plants and microbes, they often ignore the ways animals contribute to the process. That’s a mistake, says Oswald Schmitz, an ecologist at Yale who led the study, because the actions of wildlife can affect carbon cycling through “indirect multiplier effects.” For example, the massive loss of trees in North America triggered by the pine beetle outbreak has caused a net carbon change on scale with British Columbia’s current fossil fuel emissions, the researchers reported in Ecosystems. And in the Arctic, where about 500 gigatons of carbon is stored in permafrost, large grazing mammals like caribou and muskoxen can help maintain the grasslands that have a high albedo and thus reflect more solar energy. “We’re not saying that managing animals will offset these carbon emissions,” Schmitz said. “What we’re trying to say is the numbers are of a scale where it is worthwhile to start thinking about how animals could be managed to accomplish that.”