Eddie Gonzales Jr. – MessageToEagle.com – Global warming of two degrees Celsius would cause the release of an estimated 230 billion tons of soil carbon, an international team of researchers suggest.
The team led by the University of Exeter, reports that this amount of soil carbon is more than four times the total emissions from China, and more than double the emissions from the U.S., over the last 100 years.
“Our study rules out the most extreme projections—but nonetheless suggests substantial soil carbon losses due to climate change at only 2°C warming, and this doesn’t even include losses of deeper permafrost carbon,” said co-author Dr. Sarah Chadburn, of the University of Exeter.
This effect is a so-called “positive feedback”—when climate change causes knock-on effects that contribute to further climate change.
The response of soil carbon to climate change is the greatest area of uncertainty in understanding the carbon cycle in climate change projections. To address this, the researchers used a new combination of observational data and Earth System Models.
“We investigated how soil carbon is related to temperature in different locations on Earth to work out its sensitivity to global warming,” said lead author Rebecca Varney, of the University of Exeter.
State-of-the-art models suggest uncertainty of about 120 billion tons of carbon at 2°C global mean warming.
The study published in Nature Communications reduces this uncertainty to about 50 billion tons of carbon.
“We have reduced the uncertainty in this climate change response, which is vital to calculating an accurate global carbon budget and successfully meeting Paris Agreement targets,” co-author Professor Peter Cox, of Exeter’s Global Systems Institute, said.
Written by Eddie Gonzales Jr. – MessageToEagle.com Staff