With Global Warming Already Here, What Do We Do about It?

Climate change is no longer a question of "if" or "when."  The impact of warming is evident right now—and so is the human contribution.  Even if greenhouse-gas emissions are significantly reduced, the change is inevitable.  So it's time to prepare for floods, droughts and other catastrophes. That's the latest after four days of debate between scientists and government bureaucrats from more than 100 countries.  The Intergovernmental Panel on Climate Change has released the second in a series of reports on climate change.  The first concluded with 90% certainty that human activity is the main cause of global warming since 1950. Who will be hit the hardest?  What does it mean to "prepare?"  What are the potential consequences in the United States?