Mother Nature Network: In 2007, the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change (IPCC) predicted that global warming could cause sea levels to rise between 7 and 23 inches by the end of the century. A new study published this week says the actual levels of sea rise could be much higher up to three feet higher. The consequences of sea level rise at that proportion would be "horrible," the study's co-author told NBC News. Millions of people living in coastal areas would be displaced...