Are soils a solution to climate change?
Abstract
It is well established now that projected reductions of GHG emissions from different economy sectors will not suffice to maintain global warming below 2°C, nor to reach the European objective of becoming carbon neutral by 2050. Carbon removals will be needed to compensate for the emissions that cannot be reduced. Since the launch of the 4p1000 initiative “Soils for food security and climate” at the COP21 in 2015, soils are seen as a promising solution. Indeed, the soil organic carbon stocks worldwide are so large that a small increase of their size could help compensate GHG emissions.
Here, we overview the other contributions of soils to mitigating climate change, e.g. by limiting N2O emissions and to adapting to climate change, by fostering soil health and increasing their soil organic matter content. We focus on soil organic C sequestration by showing that a diversity of management options are available, by showing quantitative estimates of the technical and economic potential of soil organic carbon sequestration in agricultural soils and by discussing its intrinsic limits.
We conclude that implementing management options that are beneficial for soil health can significantly contribute to mitigating climate change, while not being “the” solution. The priority is to protect the existing soil organic carbon stocks in a context of bioeconomy development and climate change.