Increasing global temperatures will hamper the ability of soil to store carbon, with at least 55 trillion kg of the greenhouse gas expected to be released into the atmosphere by 2050, according to a new Yale University-led study published this week in the journal Nature.
While scientists had long speculated that climate change would have this kind of impact on the ability of soil to store carbon, studies on the issue have produced mixed results, with some even suggesting that the storage capacity of soil would actually increase, the university explained.
Now, a team led by Thomas Crowther, a postdoctoral fellow at the Yale School of Forestry & Environmental Studies and at the Netherlands Institute of Ecology at the time of the study, has demonstrated that increasing temperatures due to human activities will actually cause a greater than anticipated loss of carbon – about 17% more than earlier projections had indicated.
This would be roughly the same as adding a new industrialized country the same size as the US to the planet, the study authors said in a statement, and perhaps most importantly, they found that this loss will be greatest at high latitudes, in the coldest places on Earth – areas which had largely been ignored by previous studies investigating the matter, they noted.
Losses will be greatest in colder, higher-latitude regions
As the Yale-led team explained, the majority of studies exploring carbon loss in the soil looked primarily at temperate regions that were home to smaller carbon stocks. In contrast, colder, high latitude areas have massive carbon stocks that have accumulated over several thousand years and have remained relatively secure thanks to microbial activity – until now, that is.
“Carbon stores are greatest in places like the Arctic and the sub-Arctic, where the soil is cold and often frozen. In those conditions microbes are less active and so carbon has been allowed to build up over many centuries,” Crowther said in a statement. “But as you start to warm, the activities of those microbes increase, and that’s when the losses start to happen.”
The ground could be a huge contributor to carbon dioxide emissions in the future. (Credit: Joe Mania)
“The scary thing is, these cold regions are the places that are expected to warm the most under climate change,” he added. His team’s study was based on analysis of soil carbon data collected from dozens of studies involving more than 40 institutions conducted over the past two decades in several different parts of the world.
The research predicts that approximately 30 petagrams of soil carbon will be released into the atmosphere per degree of warming – twice the amount emitted due to human activity each year, the authors said. However, several factors could speed up or slow down this process, according to the Netherlands Institute, leading them to conclude that the emissions will rise between 12% and 17% by the middle of the century. This would likely cause the planet to warm by about two degrees Celsius by 2050, they added.
“Getting a handle on these kinds of feedbacks is essential if we’re going to make meaningful projections about future climate conditions,” added Crowther, who now is completing a Marie Curie Fellowship at the Netherlands Institute. “Only then can we generate realistic greenhouse gas emission targets that are effective at limiting climate change.”
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