New research combining satellite observations and computer models reveals that plant canopies are heating up faster than the surrounding air. This gap is driven by vapor pressure deficit, where dry air forces plants to close their pores to save water, stopping the natural cooling process of transpiration. This discrepancy suggests that current Earth System Models may underestimate the heat stress on vegetation. If plant temperatures continue to outpace air temperatures, it could lead to a decline in photosynthesis and weaken the land carbon sink, potentially accelerating atmospheric warming.
