Global Warming Prompting Cooling? Plant Gases Released in Warmer Temps Deflect Sunlight

Global warming may itself be driving a cooling trend, caused by the release of plant gasses prompted in the first place by higher temperatures.

According to research by the International Institute for Applied Systems Analysis and the University of Helsinki, plants release temperature-suppressing gases, or particles, that reflect sunlight back into space, thereby contributing to atmospheric cooling .

"Plants, by reacting to changes in temperature, also moderate these changes," study leader Pauli Paasonen said in a press release.

"Everyone knows the scent of the forest," said University of Helsinki researcher Ari Asmi, who also worked on the study. "That scent is made up of these gases."

While previous research predicted the counteractive effect of the plant gases on the environment, no other studies had proved its existence, except in specific cases limited to single sites and short time periods.

"One of the reasons that this phenomenon was not discovered earlier was because these estimates for boundary layer height are very difficult to do," said Paasonen. "Only recently have the reanalysis estimates been improved to where they can be taken as representative of reality."

The new findings showed the effect occurs over the long-term, in continental-size scales.

The researchers measured concentrations of plant vapors and other particles at 11 different sites around the planet.

They found as temperatures increased, plants emitted more vapors, effectively responding to the warming by increasing the cooling effect.

After being oxidized in the atmosphere, the gases released by plants tend to stick to other similar particles.

Eventually the combined particles grow larges enough to reflect sunlight and also aide in the formation of cloud droplets.

The scientists found that the effect of the increased plant emissions, however, only counters a mere 1 percent of global warming.

"This does not save us from climate warming," study Paasonen.

So, instead of being used as a direct weapon again climate change, the expulsion of plant gases can better promote the preservation of pristine natural areas like sections of the Amazon rainforest.

It's estimated the plant gas cooling effect could counter up to 30 percent of climate change in areas where there are few if any man-made particulates in the air.