A heatwave and stomata

 

 

 

Heatwave surprise: Plants’ response will make events more intense than thought

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by Peter Hannam

Environment Editor, The Sydney Morning Herald

Heatwaves in the northern hemisphere may become as much as 5 degrees warmer than previously estimated by mid-century because plants’ response to higher carbon dioxide levels has been miscalculated, according to new research by Australian scientists.

As atmospheric levels of the greenhouse gas increase, plant stomata – the tiny pores on leaves that open to take in CO2 and let out water vapour – won’t need to open as much.

“There’s less water vapour being lost so you have a net warming effect,” said Jatin Kala, a lecturer from Murdoch University and lead author of the paper that was published Monday inNature Scientific Reports.

“During a heatwave, it makes it a lot worse” not to have that evaporative cooling effect, he said.

The researchers used data from 314 plant species across 56 field sites to examine how plants responded. Existing climate models had assumed all plants would trade water for carbon in exactly the same way.

Needle-leaf forests, tundra and agricultural land used for crops would likely suffer the biggest temperature increases. Heatwaves from Europe to China were likely to become 3-5 degrees hotter than the already higher base expected from global warming, Dr Kala said.

Read the full article: Sydney Morning Herald

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