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Increased atmospheric carbon dioxide limits soil storage

Date:
April 15, 2015
Source:
Department of Energy, Office of Science
Summary:
Soil carbon may not be as stable as previously thought, scientists report, adding that soil microbes exert more direct control on carbon buildup than global climate models represent. This study, researchers say, provides insight into the mechanisms determining long-term soil carbon storage, knowledge that can be used to improve climate model representations of the global carbon cycle.
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Increased plant growth caused by rising atmospheric carbon dioxide is associated with higher rates of carbon dioxide release from soil. If rising carbon dioxide enhances soil carbon storage at all, the effect will be small. Soil carbon may not be as stable as previously thought, and soil microbes exert more direct control on carbon buildup than global climate models represent.

The Impact

This study provides insight into the mechanisms determining long-term soil carbon storage, knowledge that can be used to improve climate model representations of the global carbon cycle.

Summary

Carbon dioxide, the major cause of global warming, is released to the atmosphere when oil, coal, and gasoline are burned. Soils contain the largest pool of terrestrial organic carbon, helping counteract rising carbon dioxide levels and thus potentially playing a key role in modulating climate change. Carbon accumulates in soil through many years of plant photosynthesis and is lost from soil as microscopic organisms, mostly bacteria and fungi, decompose soil carbon, converting it back to carbon dioxide and releasing it to the atmosphere. The balance of these two processes and the future of the soil carbon sink are uncertain. How much will soil organic carbon persist, and how much of this carbon will soil microorganisms convert back to carbon dioxide? By comparing data from experiments around the world with models of the soil carbon cycle, researchers have tested how soil carbon release by microbes responds to rising carbon dioxide. They found that higher levels of atmospheric carbon dioxide increase both carbon's input and release from the soil. Thus, soil carbon may not be as stable as previously considered, and soil microbes have more direct control on carbon storage than is represented in today's global climate models.


Story Source:

Materials provided by Department of Energy, Office of Science. Note: Content may be edited for style and length.


Journal Reference:

  1. K. J. van Groenigen, X. Qi, C. W. Osenberg, Y. Luo, B. A. Hungate. Faster Decomposition Under Increased Atmospheric CO2 Limits Soil Carbon Storage. Science, 2014; 344 (6183): 508 DOI: 10.1126/science.1249534

Cite This Page:

Department of Energy, Office of Science. "Increased atmospheric carbon dioxide limits soil storage." ScienceDaily. ScienceDaily, 15 April 2015. <www.sciencedaily.com/releases/2015/04/150415090022.htm>.
Department of Energy, Office of Science. (2015, April 15). Increased atmospheric carbon dioxide limits soil storage. ScienceDaily. Retrieved May 29, 2017 from www.sciencedaily.com/releases/2015/04/150415090022.htm
Department of Energy, Office of Science. "Increased atmospheric carbon dioxide limits soil storage." ScienceDaily. www.sciencedaily.com/releases/2015/04/150415090022.htm (accessed May 29, 2017).

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