The sensitivity of global surface air temperature to vegetation greenness

Terrestrial vegetation plays a crucial role in governing the land surface energy budget, which in turn drives the climate of the Earth. The climatic feedbacks of vegetation changes are different across vegetation greenness gradients and climatological conditions, which has not been studied clearly. In this study, we used remote sensing and re-analysis datasets to investigate global climatic feedbacks of vegetation changes on the surface air temperature (SAT). The Common Land Model (CoLM) was also used to reproduce land-atmosphere energy processes and to explain the climatic feedbacks based on the biophysical mechanisms. Our results show that the sensitivity of SAT to the increase in vegetation greenness presents a convergent relationship. The sign and magnitude of the sensitivity are determined by the background climate conditions. The convergence sensitivity is regulated by the corresponding variations of satellite-observed evapotranspiration (ET) and albedo, and the associated partitioning of surface energy between sensible and latent heat fluxes simulated by the CoLM. The exploration of the global climatic feedbacks of vegetation changes in this work will be helpful to identify future climate change required for the development of appropriate strategies for mitigating global warming.

Automated summary

This study investigates the global climatic feedbacks of vegetation changes on surface air temperature using remote sensing and re-analysis datasets, as well as the Common Land Model. The results show that the sensitivity of surface air temperature to an increase in vegetation greenness is determined by background climate conditions, with convergence sensitivity being influenced by satellite-observed evapotranspiration and albedo.