During droughts, forests can shift from absorbing carbon dioxide (CO₂) to emitting more than they take in. Multiple outlets explain that trees rely on water to run photosynthesis, the process that pulls CO₂ from the atmosphere. When water becomes scarce, trees stop or reduce this water-intensive process, disrupting a key natural mechanism for carbon capture.
The reporting links this shift to the physiology of leaves and the water demands of photosynthesis. One source highlights that, to survive dry spells, trees pause photosynthesis, which can cause forests to lose their ability to absorb CO₂. Another adds a quantitative point about the water cycle around photosynthesis, noting that for each CO₂ molecule absorbed, trees release hundreds of water molecules on average. Together, the sources describe how extended drought conditions can alter forest carbon balance.
