What an ancient comet collision teaches us about global warming

A comet impact 56 million years ago on Earth contributed to global warming, say scientists after studying tiny glass spheres, or microtektites, found in ancient sediment from a period of massive climate change.  http://www.csmonitor.com/Science/2016/1014/What-an-ancient-comet-collision-teaches-us-about-global-warming?cmpid=ema:nws:Daily%2520Newsletter%2520%2810-14-2016%29&utm_source=Sailthru&utm_medium=email&utm_campaign=20161014_Newsletter:%20Daily&utm_term=Daily
Article courtesy of The Christian Science Monitor by Christina Beck