Trees in warmer, water-scarce regions emit two times higher carbon dioxide: Study

A groundbreaking study by a team led by the Pennsylvania State University has revealed that trees, which are considered the lungs of our planet Earth, release more carbon dioxide (CO2) in warmer and drier climates.

"With an analysis of a global dataset of tree tissue, a team led by Penn State researchers demonstrated that the rate of photorespiration in trees is up to two times higher in warmer climates, especially when water is limited," Penn State said.

The study was led by researcher Max Lloyd at Penn State. This unexpected revelation challenged the prevailing notion of trees as climate change warriors and prompted urgent questions about the implications for our global future.

Notably, reducing carbon dioxide emissions is crucial for mitigating climate change, as this is a major greenhouse gas contributing to global warming.

The research also highlighted that trees in regions with heightened temperatures and water scarcity engage in accelerated photorespiration. Photorespiration is a process that occurs in the cells of plants during photosynthesis, particularly in conditions of high temperatures.

Photorespiration involves the uptake of oxygen and release of carbon dioxide by the plant, in contrast to the primary photosynthesisprocess, which involves the inhaling of carbon dioxide and release of oxygen by trees.

So, essentially Photorespiration reverses the carbon-capturing process of photosynthesis. "We have knocked this essential cycle off balance," said Lloyd.

"Plants and climate are inextricably linked. The biggest draw-down of CO2 from our atmosphere is photosynthesising organisms. It's a big knob on the composition of the atmosphere, so that means small changes have a large impact," he added.

The study also uncovered that trees in these challenging conditions can emit about double the CO2 as their counterparts in cooler and wetter surroundings. Currently, plants absorb around 25 percentof human-emitted CO2, acting as a crucial carbon sink.

Beyond the alarming headlines, the study offers a silver lining. Through an innovative method of measuring photorespiration using wood samples, researchers can now predict future tree "breathing" and unravel the past by examining fossilised wood.

(With inputs from agencies)