Closed Plant Pores may be a Factor Behind Worsening Heat Waves

Contrary to previous climate models, heatwaves may become much worse than what was predicted and plant pores play a significant role.

According to an IFLScience report, climate scientists have previously underestimated the full impact of heatwaves that affect northern Europe, and overestimated the coolling effects that plants can offer.

A plant's cooling effect is mainly attributed to its capacity to dissipate heat through their pores, also known as stomata. Plants also help sequester carbon dioxide from the atmosphere, aiding in the cooling process.

These functions, however, could be less efficient if the plant pores become closed or too narrow during certain seasons and environmental conditions.

The role of the stomata was detailed in a scientific paper recently published in the journal Nature. 314 plant species were studied, in which some closed their pores unexpectedly narrower, releasing less water and absorbing less heat.

The study emphasized that previous climate models did not consider the stomatal water-use that could affect heatwave intensity. If the plant pores are too narrow to release water, it absorbs less heat from our increasingly warm planet.

Previous models assumed that all plants respond similarly to environmental changes in temperature and carbon dioxide concentration, using the same C3 photosynthesis pathway.

But this time, responses among different plants varied.

According to a report by SciMex, the stomatal factor could boost heatwaves by as much as 5 degrees Celsius (41 degrees Fahrenheit). Europe and China are likely to be seriously affected by heatwaves based on the revised climate models.

The new study predicted that the largest temperature increase will occur over needleleaf forests and tundra, where the rate of heat dissipation among plants is very low.