The massive glacier that formed the Great Lakes is disappearing — and greenhouse gases are to blame for its untimely demise
by from on (#4A9PJ)
![B88608937Z.1_20190303154650_000_GQIGT1VU](http://media.zuza.com/5/e/5e83cd4a-e10b-44b7-8e08-740260dd2279/B88608937Z.1_20190303154650_000_GQIGT1VU.3-0_Content.jpg)
From a boardwalk overlooking Chicago's deserted Ohio Street Beach in the throes of winter, it's not hard to imagine the last ice age. A blanket of fresh snow covers the shoreline and pale blue ice glazes over Lake Michigan as far as the eye can see.