Ethanol doesn't burn cleaner than gasoline, nor is it cheaper.
Bill Gates is a relative newcomer to the fight against global warming, but he's already shifting the debate over climate change.
In the U.S. alone, weather disasters caused $50 billion in economic damages in 2010.
In reality, studies show that investments to spur renewable energy and boost energy efficiency generate far more jobs than oil and coal.
Some studies suggest that the Arctic Ocean may be ice-free by the end of the century.
Some studies have shown that natural gas could, in fact, be worse for the climate than coal.