The EPA made what is called an “endangerment finding” a while back which asserts that it is appropriate to regulate the release of greenhouse gasses. This was challenged in court by science deinialists and energy interests via “the state of Virginia, the industry front-group Coalition for Responsible Regulation, the U.S. Chamber of Commerce, and the Tea Party-industry front Southeastern Legal Foundation.”
Brad Johnson has a post outlining the situation here.
The endangerment finding is based on a large and internally consist ant corpus of scientific findings. The argument against the finding is in conflict with what we know from a scientific perspective, and is rather self serving for the interests involved.