Non-radiative effects dominate the local surface temperature response to land-cover change-Insights from a semi-empirical model.

Land-cover change (LCC) is an important driver of climate change through carbon emissions (biochemical effects), but also through changes in the surface energy balance (biophysical effects). Quantifying magnitude and sign of surface temperature responses to biophysical effects is still challenging and under debate. We develop a new semi-empirical model based on a linearized surface energy balance for biophysical and an empirical model for the biochemical responses to LCC. Neglecting indirect effects, we find average global direct biophysical and biochemical warmings in response to a stylized deforestation scenario (1.22 K and 0.50 K) and historical LCC (0.42 K and 0.15 K), whereas an afforestation experiment leads to cooling (-1.95 K and -0.96 K). Our results underline the non-negligible impact of biophysical effects, especially non-radiative effects, and stress the importance of including these in the assessment of climate change mitigation and adaptation policies.