Billions of Tons Carbon in Soil Will Be Released if Global Warming Reaches 2 Degrees

According to new research from scientists of the University of Exeter, billions of tons of carbon in the soil will be released if global warming reaches 2°C.

Carbon from the soil

This 2°C increase in the global average temperature will cause carbon that amounts to approximately 230 billion tons will be released from soil when further warming reaches this particular threshold.

Soils have two or three times additional carbon content compared to the carbon that is in our atmosphere. High temperature speeds up the decomposition process, which decreases the time that carbon spends locked within the soil. This is called soil carbon turnover.

A new study

The finding was revealed by a new study from an international research team which was published in the journal Nature Communications.

The study was spearheaded by scientists from the University of Exeter and shows the sensitive nature of this carbon turnover to the influence of climate change. It doubles the uncertainty made by past projections on climate change consequences.

The research team estimated that soil carbon amounting to 230 billion tons would be released when the warmth of the globe reaches 2°C above the global temperature level of the pre-industrial age.

This is over four times China's total carbon emissions and over twice the carbon emissions of the US in the past one hundred years.

Positive feedback effect

According to Dr. Sarah Chadburn, the study co-author from the University of Exeter, their study does not include the most extreme future projections. However, they nevertheless suggest that there will be substantial losses of the carbon in the soil as an effect of the warming level of 2°C.

Dr Chadburn explains that their estimate is exclusive of the carbon losses in the deeper permafrost regions.

The effect that the research team describes is a positive feedback mechanism. It involves the impact of contributing factors to climate change to cascade or knocks off more products that further contribute to even more climate change.

In science's effort to understand the behavior and effect of the carbon cycle in projections of climate change, it is the soil carbon's response to global warming that represents the most significant uncertainty factor.

The conduct of the research

The research team addressed this uncertainty by using a novel technique of combining Earth System Models and actual observational data. This simulates the carbon cycle and climate cycle, which subsequently produces predictions for climate change that are hopefully more accurate.

According to the University of Exeter's Rebecca Varney, the lead study author, the research team looked at how soil carbon relates to temperatures in various areas on the planet to determine its sensitivity to the climate change phenomenon.

The study started from a level of uncertainty of 120 billion tons of carbon at the level of 2° C warming and reduced it to approximately 50 billion tons.

According to Exeter Global Systems Institute professor Peter Cox, who is also a study co-author, the team reduced this uncertainty in the carbon soil content to calculate a more accurate worldwide carbon budget to help successfully meet the targets of the Paris Agreement to stem global warming.

Check out more news and information on Global Warming on Nature World News.