As the Earth warms, it releases trapped carbon into the atmosphere. Just how much is likely to be released and the impact it could have on the planet has been the subject of much debate. EU-funded researchers can now offer new insights into likely soil activity in climate-change scenarios.
© #219412870 | Author: Alexey Slyusarenko, 2018 fotolia.com
The EU-funded TRAIT project investigated the tangible links between the activity of soil microbial communities and the global carbon cycle by quantifying the effects of warming on soil carbon losses at a global scale.
As a result, Tom Crowther, a Marie Skłodowska-Curie research fellow, and the TRAIT team estimate that 55 trillion kilograms of carbon could be released into the atmosphere from the soil by 2050 if climate change is not stopped.
The effect will be roughly equivalent to adding another industrialised country to the planet, the size of the United States, according to the TRAIT teams reporting of warming-induced changes in soil carbon stocks based on data from 49 field experiments across North America, Europe and Asia.
The researchers used a combination of trait-based and community-scale approaches to explore the relative importance of microbial community composition and climate conditions in governing patterns of acclimation potential across landscapes. For this, they had to feed the microbial physiological information into Earth system models, climate scenarios and other techniques to gain better insight.
Among other discoveries, they found that the effects of warming are contingent on the size of the initial soil carbon stock, with considerable losses occurring in high-latitude areas. Built up over thousands of years, the release of these sub-Arctic, high-altitude stocks is expected to be accelerated by climate change because micro-organisms in the soil are likely to become more active.
Factors that could slow or speed up this process further must be factored into climate-change scenarios, the researchers believe. With more carbon dioxide in the atmosphere, for instance, plant growth is accelerated. Findings and further insights from the project are presented in a short film and have been published in the journal Nature.