Researchers at the University of British Columbia found that extreme heat damages plant leaves and reduces their ability to absorb carbon [1, 2].
This discovery suggests that current climate models may underestimate the pace of global warming. If plants cannot effectively capture carbon or maintain water levels during heat waves, the natural systems intended to mitigate climate change could fail [1, 2, 3].
Assistant professor Sean Michaletz and his team observed that extreme temperatures trigger a dramatic increase in water loss through transpiration [1, 2]. This process weakens the plant's overall health and reduces photosynthetic carbon uptake [1, 3]. As leaves sustain damage from the heat, they become less efficient at scrubbing carbon dioxide from the atmosphere [2, 3].
These findings indicate a critical gap in how scientists predict environmental responses to rising temperatures. Most models do not fully account for the specific ways extreme heat disrupts plant physiology, a defect that could alter the role of vegetation in the fight against climate change [1, 2, 3].
"These increased water loss rates have really big implications for climate change," Michaletz said [1].
The study, reported in March 2026, highlights a feedback loop where rising temperatures damage the very biological tools used to cool the planet [2]. When plants lose water too quickly, they may shut down carbon absorption entirely to survive, leaving more greenhouse gases in the air [1, 2].
“Extreme heat damages plant leaves and reduces their ability to absorb carbon.”
This research suggests that the 'carbon sink' provided by global forests and grasslands is more fragile than previously assumed. If extreme heat events become more frequent, the biological capacity of the earth to sequester carbon will diminish, meaning human-led emission reductions must be even more aggressive to compensate for the loss of natural mitigation.
