2016-01-21. What’s behind the Arctic’s increasing carbon dioxide fluctuations?

posted Jan 28, 2016, 10:10 AM by Alan Gould
By Sid Perkins, Science (AAAS). For GSS BOOK chapter 6, Investigation 6-1. Excerpt: It’s no mystery why carbon dioxide (CO2) levels fluctuate with the seasons: As greenery grows in the spring and summer, it soaks up the planet-warming gas, and when trees shed their leaves in the autumn, some of that gas returns to the atmosphere. But scientists haven’t figured out why the differences between summer and winter concentrations of CO2 have been growing substantially at Arctic latitudes since the 1960s—in some regions, the fluctuations have increased as much as 25%. A new computer simulation fingers long-term warming in the Arctic, which has led to the proliferation of plants across large swaths of the landscape....  http://www.sciencemag.org/news/2016/01/what-s-behind-arctic-s-increasing-carbon-dioxide-fluctuations