Historical and future perspectives of global soil carbon response to climate and land-use changes

• Published in: Tellus B: Chemical and Physical Meteorology
• Main Authors: Eglin, T., Ciais, P., Piao, S. L., Barre, P., Bellassen, V., Cadule, P., Chenu, C., Gasser, T., Koven, C., Reichstein, M., Smith, P.
• Other Authors: Eglin, T (reprint author), CEA CNRS UVSQ, IPSL LSCE, Lab Sci Climat & Environm, Gif Sur Yvette, France., CEA CNRS UVSQ, IPSL LSCE, Lab Sci Climat & Environm, Gif Sur Yvette, France., Peking Univ, Dept Ecol, Coll Urban & Environm Sci, Beijing 100871, Peoples R China., AgroParisTech, Bioemco UMR7618, F-78850 Thiverval Grignon, France., Ecole Normale Super, Geol Lab, UMR 8538, F-75005 Paris, France., Max Planck Inst Biogeochem, Biogeochem Model Data Integrat Grp, D-07745 Jena, Germany., Univ Aberdeen, Sch Biol Sci, Inst Biol & Environm Sci, Aberdeen AB24 3UU, Scotland.
• Format: Journal/Newspaper
• Language: English
• Published: tellus series b chemical and physical meteorology 2010
• Subjects: C-13 NATURAL-ABUNDANCE; NET PRIMARY PRODUCTION; ORGANIC-MATTER; ATMOSPHERIC CO2; TEMPERATURE SENSITIVITY; AGRICULTURAL SOILS; PERMAFROST CARBON; EUROPEAN FORESTS; TERRESTRIAL BIOSPHERE; CYCLE FEEDBACKS; permafrost
• Online Access: https://hdl.handle.net/20.500.11897/395345; https://doi.org/10.1111/j.1600-0889.2010.00499.x

In this paper, we attempt to analyse the respective influences of land-use and climate changes on the global and regional balances of soil organic carbon (SOC) stocks. Two time periods are analysed: the historical period 1901-2000 and the period 2000-2100. The historical period is analysed using a synthesis of published data as well as new global and regional model simulations, and the future is analysed using models only. Historical land cover changes have resulted globally in SOC release into the atmosphere. This human induced SOC decrease was nearly balanced by the net SOC increase due to higher CO2 and rainfall. Mechanization of agriculture after the 1950s has accelerated SOC losses in croplands, whereas development of carbon-sequestering practices over the past decades may have limited SOC loss from arable soils. In some regions (Europe, China and USA), croplands are currently estimated to be either a small C sink or a small source, but not a large source of CO2 to the atmosphere. In the future, according to terrestrial biosphere and climate models projections, both climate and land cover changes might cause a net SOC loss, particularly in tropical regions. The timing, magnitude, and regional distribution of future SOC changes are all highly uncertain. Reducing this uncertainty requires improving future anthropogenic CO2 emissions and land-use scenarios and better understanding of biogeochemical processes that control SOC turnover, for both managed and un-managed ecosystems. Meteorology & Atmospheric Sciences SCI(E) 22 REVIEW 5,SI 700-718 62