Wei-Hock Soon, a scientist at the Harvard-Smithsonian Center for Astrophysics, is a leading global warming skeptic. His work has been used by pundits and politicians alike to deny the existence of man-made climate change. He says global warming is caused by the sun, not humans. But documents obtained by Greenpeace show that Soon has received more than $1 million in research funding from oil and coal companies, which he’s never disclosed when publishing his research. We find out just how influential Soon is, and how well-funded.