14 DAY TRIAL // As common knowledge has it, plants and oceans are the main engines that absorb the dangerous greenhouse gas carbon dioxide (CO2) from our planet's atmosphere. Increased concentrations of the gas have been linked to the global warming effect that causes climate change, and so caring for Earth's natural carbon sinks should be very high on our priority list. But a new groundbreaking study throws serious doubts on this idea. The research would seem to suggest that plants actually contribute to global warming.
Researchers at the Carnegie Institution for Science (CIS) were behind the new investigation, which, if proven true beyond a reasonable doubt, could change the way we look at plants. Biologists say that vegetation is the only life form that can make photosynthesis, a process through which carbon dioxide and sunlight are converted into oxygen and energy. But the CIS study shows that existing CO2 levels actually make the plants work for global warming, and not against it, LiveScience reports.
“There is no longer any doubt that carbon dioxide decreases evaporative cooling by plants and that this decreased cooling adds to global warming. This effect would cause significant warming even if carbon dioxide were not a greenhouse gas,” explains CIS team member and scientist Long Cao. He is also a coauthor of the new investigation, details of which were published in the latest issue of the esteemed journal Proceedings of the National Academy of Sciences (PNAS). The group explains that the mechanisms through which plants contribute to the disastrous global phenomenon is not direct.
They say that increased temperatures and carbon dioxide levels force the plants to retain more water within their leaves. These amounts of water would have otherwise evaporated in the atmosphere, helping to cool it, and therefore reduce the intensity of global warming. The difference is apparently considerable, the team says. It has been estimated that water retention can increase local temperatures at certain locations by up to 25 percent above the levels caused by the greenhouse effect on its own. Statistics show that 16 percent of the temperature increase on land masses is attributable to water retention from plants, with the remaining 84 percent attributable to global warming.
“We need to take great care in considering what kind of changes we make to forests and other ecosystems, because they are likely to have important climate consequences,” explains Ken Caldeira, who is a coauthor of the PNAS paper, and also a scientist at CIS.