It became known as Climategate - casting doubt on an international global warming report. But now five investigations have cleared Penn State Professor Michael Mann, saying his science is sound. Susan McGinnis talked with Mann on what the investigations mean to him, the fight against global warming and his future. The Obama administration wants emissions from coal fired power plants cut down - but could this be a back-breaker for coal providers? What does this mean for ratepayers? And what does it mean for young kids, the elderly and people with asthma? Tyler Suiters takes a look at the new regulations proposed for the Clean Air Interstate Rule. Plus, could a half million dollar switch make the multi-billion dollar world of offshore oil and gas drilling safer? Critics say yes, the oil industry says no. Dan Goldstein looks into why acoustic switches aren't used in the United States, but are mandatory in other countries. Why U.S. oil companies use the switches abroad, but not in U.S. waters. And whether the Deepwater Horizon explosion could have been stopped. Finally, using nature to clean up polluted brownfields. Lee Patrick Sullivan takes us to Argonne Natural Laboratories where scientists are using trees to suck out dirty elements from the soil, to turn brown to green.