Fareed Zakaria interviews Energy Secretary Steven Chu, who turns out to be a total downer:Can we really prevent global warming? Or should we be thinking more about adaptation? Building coastal fortifications may be cheaper than halting the release of CO2.Right now, the climate scientists feel that if all humans shut off carbon emissions today, it will still glide up by about 1 degree centigrade. In the business-as-usual scenarios, Nicholas Stern says there's a 50 percent chance we may go to 5 degrees centigrade. We know what the Earth was like 5 or 6 degrees centigrade colder. That was called the Ice Ages. Imagine a world 5 degrees warmer. The desert lines would be dramatically changed. The West is projected to be in drought conditions. And certain tipping points might be triggered. We can adapt to 1 or 2 degrees. More than that, there is no adaptation strategy.
