When the Vikings discovered Greenland it was green with various kinds of grasses. They settled there and raised cattle. 500 years later the Earthb started cooling and Greenland became covered with ice and snow!!! Global warming is Al Gores HOAX----it has made him a billionaire!!
Earth warms and cools on a 27 year cycle. The last warming year was 1995. The Earth is now cooling so you'd best not lose your longjohns nor overcoat!!!!