Global soil profiles indicate depth-dependent soil carbon losses under a warmer climate

Soil organic carbon (SOC) changes under future climate warming are difficult to quantify in situ. Here we apply an innovative approach combining space-for-time substitution with meta-analysis to SOC measurements in 113,013 soil profiles across the globe to estimate the effect of future climate warming on steady-state SOC stocks. We find that SOC stock will reduce by 6.0 ± 1.6% (mean±95% confidence interval), 4.8 ± 2.3% and 1.3 ± 4.0% at 0-0.3, 0.3-1 and 1-2 m soil depths, respectively, under 1 °C air warming, with additional 4.2%, 2.2% and 1.4% losses per every additional 1 °C warming, respectively. The largest proportional SOC losses occur in boreal forests. Existing SOC level is the predominant determinant…

• UD
  U.S. Department of Energy

  Awards: DE-NA0003525, 0003525, NA0003525, -NA0003525, DE-NA-0003525
• NN
  National Natural Science Foundation of China

  Awards: DE-NA-0003525, 32171639, 41930754, 41930754, 32171639
• NN
  National Nuclear Security Administration

  Awards: DE-NA0003525, NA0003525, DE-NA-0003525
• SN
  Sandia National Laboratories

  Awards: NA0003525, DE-NA-0003525, DE-NA0003525