Once a skeptic re climate change

Mark Serreze has spent more than 35 years studying snow, ice and cold places and is now Research Professor of Geography and director, National Snow and Ice Data Center at the University of Colorado. He was once skeptical that human activities were playing a role in climate change. Now he says:

Evidence that the Arctic is warming rapidly extends far beyond shrinking ice caps and buckling roads. It also includes a melting Greenland ice sheet; a rapid decline in the extent of the Arctic’s floating sea ice cover in summer; warming and thawing of permafrost; shrubs taking over areas of tundra that formerly were dominated by sedges, grasses, mosses and lichens; and a rise in temperature twice as large as that for the globe as a whole. This outsized warming even has a name: Arctic amplification.