The Potential of Agricultural Land Management to Contribute to Lower Global Surface Temperatures
This study sought to understand the scale of global mean surface temperature reduction that is achievable by sequestering soil carbon on existing agricultural lands using known management changes.
The results indicate that significant global temperature reductions, on the order of 0.1 to up to 0.25 degrees C are plausible by 2100 without expanding or contracting agricultural landcover and without disrupting agricultural production.
Removal of atmospheric carbon dioxide (CO2) combined with emission reduction is necessary to keep climate warming below the internationally agreed upon 2°C target. Soil organic carbon sequestration through agricultural management has been proposed as a means to lower atmospheric CO2 concentration, but the magnitude needed to meaningfully lower temperature is unknown. This study showed that sequestration of 0.68 Pg C year-1 for 85 years could lower global temperature by 0.1°C in 2100 when combined with a low emission trajectory [Representative Concentration Pathway (RCP) 2.6]. This is potentially achievable using existing agricultural management approaches, without decreasing land area for food production. Existing agricultural mitigation approaches could lower global temperature by up to 0.26°C under RCP 2.6 or as much as 25% of remaining warming to 2°C. This declines to 0.14°C under RCP 8.5. Results were sensitive to assumptions regarding the duration of carbon sequestration rates, which is poorly constrained by data. Results provide a framework for the potential role of agricultural soil organic carbon sequestration in climate change mitigation.
Climate and Ecosystem Sciences Division, Lawrence Berkeley National Lab
- Rathmann Family Foundation
- EESM: Quantification of Land-use/Land Cover Change as Driver of Earth System Dynamics
Mayer, A., Z. Hausfather, A. Jones, W. Silver. “The Potential of Agricultural Land Management to Contribute to Lower Global Surface Temperatures.” Science Advances 4(8), eaaq0932 (2018). [DOI:10.1126/sciadv.aaq0932]