Carbon sequestration in soils cannot fix climate change to the extend it was thought to

Soil as carbon storehouse needs to be part of, not the whole solution

Soil as carbon storehouse needs to be part of, not the whole solution

Carbon sequestration in soils was a proposed method to reduce atmospheric carbon dioxide. However, according to a recent study, soil alone cannot be counted on to save us from climate change. Scientists from the University of California, Irvine (UCI) have found that soil’s potential to soak up CO? over the coming century has been overestimated by as much as 40%.

They gathered 1-meter (3.28 ft) deep soil samples from 157 places around the world, and analyzed them with sophisticated carbon dating methods in order to improve the way that soil carbon is represented in some of the best Earth System Models (ESMs). They found that models used by the UN’s Intergovernmental Panel on Climate Change (IPCC) may have been overestimating how much carbon would likely be stored in soils under climate change, meaning that it may take hundreds or even thousands of years for soils to soak up large amounts of the extra CO? pumped into the atmosphere by human activity. Their findings suggested that the size of the soil carbon “sink” that could effectively mitigate climate change is lower than previously estimated (by anywhere from 5.9% to 87%). Scientists conclude that models need to represent soil carbon more accurately when simulating climate change scenarios and that our focus should be on improving emissions reduction strategies.

“It will take a very long time for soil to soak up the carbon, there is a timescale mismatch in terms of climate change,” said Yujie He, a UCI postdoctoral scholar and lead author of the study. “The soil will eventually be a large carbon sink, but it won’t be present in the next century. I don’t think we can increase that absorption ability, so we may want to make more proactive action to mitigate climate change, such as cuts to fossil fuel emissions, for example”, she said.

Source:The Guardian