Climate Change Could Be Accelerated By Carbon Loss In Soil

Increased levels of carbon dioxide in the atmosphere cause soil microbes to produce more carbon dioxide, accelerating climate change, according to a recent study.

Increased levels of carbon dioxide accelerate plant growth, which causes more absorption of carbon dioxide through photosynthesis, according to a press release.

Research from scientists at the Northern Arizona University challenges previous understandings about how carbon accumulates in soil. It was believed that the carbon dioxide is then stored in wood and soil for a long time, slowing climate change. Yet this new research suggests that the extra carbon provides fuel to microorganisms in the soil whose byproducts (such as carbon dioxide) are released into the atmosphere, contributing to climate change.

"Our findings mean that nature is not as efficient in slowing global warming as we previously thought," Kees Jan van Groenigen, lead author of the study and research fellow at the Center for Ecosystem Science and Society at Northern Arizona University, said in a statement. "By overlooking this effect of increased CO2 on soil microbes, models used by the Intergovernmental Panel on Climate Change may have overestimated the potential of soil to store carbon and mitigate the greenhouse effect."

For the study, researchers analyzed published results from 53 different experiments in forests, grasslands and agricultural fields around the world to better understand how soil microbes respond to the changing atmosphere. The experiments they reviewed all measured how extra carbon dioxidein the atmosphere affects plant growth, microbial production of carbon dioxide, and the total amount of soil carbon at the end of the experiment.

"We've long thought soils to be a stable, safe place to store carbon, but our results show soil carbon is not as stable as we previously thought," Bruce Hungate, study author and director of the Center for Ecosystem Science and Society at northern Arizona University, said in a statement. "We should not be complacent about continued subsidies from nature in slowing climate change."

The findings were recently published in the journal Science.