The Arctic is greening. Early this month NASA released research findings that Quebec, western Alaska, and some other areas turned greener from 1984 to 2012. NASA images reveal swaths of greenery in a part of the world we usually think of as being white. Now a scientific study published this week in Nature Climate Change backs up the crazy green images and confirms the trend is due to humans.
The authors of the study say it is the “first clear evidence of a discernible human fingerprint on physiological vegetation,” and greenhouse gases coming from humans have contributed to the greening. Multiple researchers from American, French, and Chinese institutions contributed to the study. Using a “detection and attribution algorithm,” the researchers attempted to see if the greening trend would occur if human activity was not present, and if it would happen if natural forces were the only factor.
The results were clear: greening can be attributed to “human greenhouse gas emissions.” Oak Ridge Laboratory research scientist Jiafu Mao, lead author on the paper, told The Washington Post, “We first find this kind of human fingerprint…particularly the greenhouse gas impact, on this kind of enhanced vegetation growth.”
Couldn’t those plants absorb carbon, however, mitigating climate change? Mao said it is “hard to predict” how greening will impact climate change in the future, or even if the trend will continue. Some do think greening could at least dull the worst effects precipitated by more greenhouse gas emissions.
Instead of being a good sign, though, others think greening should remind us how much our activities are affecting the planet. Climate scientist Richard Betts of the Met Office Hadley Center wrote a piece for Carbon Brief this spring focusing on carbon emissions and indicated climate scientists are still studying how plants are responding to climate change. He said, “While we are perhaps lucky that CO2 has this effect on plant physiology, in addition to being a greenhouse gas, it is not our ‘get out of jail free’ card when it comes to our ongoing emissions of CO2.”