A new study published in One Earth challenges the long-held assumption that plants increase carbon absorption by adapting their photosynthesis to higher temperatures. Researchers analyzed 20 years of global data and found that the optimal temperature for photosynthesis barely shifted. Instead, plants are pulling in more carbon because they use water more efficiently and grow larger canopies. This finding has major implications for climate models. If models rely only on temperature response to predict future carbon storage, they will miss the dominant factors. Water efficiency and canopy expansion, including human-led restoration in dry regions, are driving the increase. The study suggests that predicting future carbon sinks requires a deeper understanding of how plants manage water and build leaves, not just how they handle heat.
