Large-scale commodity agriculture exacerbates the climatic impacts of Amazonian deforestation

Proc Natl Acad Sci U S A. 2021 Feb 16;118(7):e2023787118. doi: 10.1073/pnas.2023787118.

Abstract

In the Amazon rainforest, land use following deforestation is diverse and dynamic. Mounting evidence indicates that the climatic impacts of forest loss can also vary considerably, depending on specific features of the affected areas. The size of the deforested patches, for instance, was shown to modulate the characteristics of local climatic impacts. Nonetheless, the influence of different types of land use and management strategies on the magnitude of local climatic changes remains uncertain. Here, we evaluated the impacts of large-scale commodity farming and rural settlements on surface temperature, rainfall patterns, and energy fluxes. Our results reveal that changes in land-atmosphere coupling are induced not only by deforestation size but also, by land use type and management patterns inside the deforested areas. We provide evidence that, in comparison with rural settlements, deforestation caused by large-scale commodity agriculture is more likely to reduce convective rainfall and increase land surface temperature. We demonstrate that these differences are mainly caused by a more intensive management of the land, resulting in significantly lower vegetation cover throughout the year, which reduces latent heat flux. Our findings indicate an urgent need for alternative agricultural practices, as well as forest restoration, for maintaining ecosystem processes and mitigating change in the local climates across the Amazon basin.

Keywords: Amazon forest; agricultural expansion; deforestation; land use; regional climate.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture / statistics & numerical data*
  • Climatic Processes*
  • Conservation of Natural Resources / statistics & numerical data*
  • Ecosystem