Extracting oil from the tar sands is a nasty, polluting, energy-intensive business.

Compared to coal, which generates almost half the electricity in the United States, natural gas is indeed a cleaner, less polluting fuel. But compared to, say, solar, it's filthy. And of course there is nothing renewable about natural gas.

This Dewdrop World is a beautiful, courageous, intimate film about love and loss. It may also be the deepest meditation on climate change that I've ever seen.

Mark Ruffalo, aka the Incredible Hulk, is the natural gas industry's worst nightmare: a serious, committed activist who is determined to use his star power as a superhero in the hottest movie of the moment to draw attention the environmental and public health risks of fracking.

In reality, studies show that investments to spur renewable energy and boost energy efficiency generate far more jobs than oil and coal.

When it comes to energy, cost isn't everything - but it's a lot. Everybody wants cheap power.

Bloomberg's $50 million is not going to revolutionize the electric power industry. But his willingness to fight is already inspiring others to see Big Coal differently.