CBS News - A leaked UN report warns 'worst is yet to come' on climate change.
A leaked draft report from the United Nations' Intergovernmental Panel on Climate Change paints the starkest picture yet of the accelerating danger caused by human use of coal, oil, and gas. It warns of coming unlivable heat waves, widespread hunger and drought, rising sea levels and extinction. To understand the report's warnings, William Brangham turns to atmospheric scientist Katharine Hayoe.