Spatiotemporal dynamics in vegetation-temperature feedback and overly optimistic representations in climate models

The vegetation-temperature feedback significantly influences local climate variability. While previous studies have assessed the responses of local temperature to vegetation biomass changes, they often suffer from the mix of long-term global warming trends and localized vegetation-temperature interactions. More importantly, the temporal evolutions of this feedback remain elusive. Here, we use a novel approach to analyze spatiotemporal variations of this local feedback while controlling for global warming trends. Our findings reveal a weakening role of vegetation in cooling the earth over the past four decades, with a nonlinear feedback change modulated by background climatologic conditions. Furthermore, an evaluation of state-of-the-art climate models shows a systematic overestimation of vegetation cooling effects, particularly in densely vegetated regions. This overly optimistic bias contributes to a significant underestimation of global warming, highlighting the need to improve the representation of vegetation-climate interactions in climate models.