India, July 13 -- Tropical forests are being increasingly pushed beyond their threshold limits, affecting their ability to perform photosynthesis and thus their capacity to absorb carbon dioxide, a new study has found.

The study, published in the Proceedings of the National Academy of Sciences, noted that plants have a safety margin of about 15 degrees Celsius where they can perform photosynthesis. But extreme weather events along with droughts and global warming narrow down their safety margins drastically.

Human bodies get affected by heat waves, making them unable to function efficiently. Similarly, trees reach their limits as temperatures exceed beyond tolerance capacity.

"Above a certain critical temperature, photosynthesis, the p...