If you've never heard of Charles or David Koch, I wouldn't blame. While they do run the second largest private company in the US, they don't spend much money advertising the fact.
These oil barons do however spend a lot of money every year on organizations like Americans for Prosperity who attack the science of climate change and deny that it is happening.
Here's a backgrounder on Koch just released yesterday by Climate Science Watch.
And here's Greenpeace's "Climate Crime Unit" on the hunt for Charles and David Koch: