New research shows that global warming will cause the world’s soil to release carbon.
The scientists used data from more than 9,000 soil samples from around the world and found that as the average temperature rises, the carbon storage “drops sharply”.
This is an example of “positive feedback”, where global warming causes more carbon to be released into the atmosphere, further accelerating climate change.
Vulnerable
Importantly, the amount of carbon that can be released depends on the type of soil. Coarse (low clay) soil loses three times as much carbon as fine (rich clay) soil.
Researchers from the University of Exeter and Stockholm University said their findings helped determine fragile carbon stocks and provided an opportunity to improve the Earth System Model (ESM) that simulates future climate change.
“Because the carbon stored in the soil is more than the carbon stored in the atmosphere, the sum of all the trees on the earth, even if a small part is released, may have a significant impact on our climate,” said Professor Ian Hartley Exeter School of Life and Environmental Sciences.
“Our analysis shows that carbon storage in rough soils at high latitudes (far from the equator) may be the most vulnerable to climate change.
“Therefore, given the high rate of warming that occurs in colder regions, this type of storage may require special attention. In contrast, we found that carbon storage in the fine-textured soils of tropical regions is less susceptible to climate warming.”
temperature
The data of 9,300 soil profiles comes from the World Soil Information Database, and the research focus is on the top 50 cm of the soil.
By comparing carbon storage in places with different average temperatures, the researchers estimated the possible impact of global warming.
Every 10°C increase in temperature reduces the average carbon storage of all soils by more than 25%.
Professor Hartley said: “Even bleak predictions did not anticipate this degree of warming, but our use of this scale makes us believe that the effects we observe are caused by temperature rather than other variables.”
“Our results clearly show that as the temperature rises, more and more carbon is released from the soil.
Activity
“It is important to note that our research did not examine the time scale involved, and further research is needed to investigate how much carbon can be released this century.”
The researchers found that the established ESM cannot represent their results. “This shows that there is an opportunity to use the patterns we have observed to improve the way the model represents the soil and further reduce the uncertainty of the prediction,” said Professor Hartley.
There are differences in carbon storage based on soil texture, because finer soil provides more mineral surface area for carbon-based organic materials, thereby reducing the ability of microorganisms to enter and decompose it.
The paper was published in a journal Nature Communications, Have the right The effect of temperature on carbon storage is controlled by soil stability.
The University of Exeter launched a “Green Future” Campaign And websites to promote action on environmental and climate emergencies.
This author
Brendan Montague is EcologistThis article is based on a press release from the University of Exeter.
