I saw this headline today:

You see this kind of claim all over conspiracy theory sites online, but it’s just that: a silly conspiracy theory. Let me explain. This is the same as the Surgeon General saying that “We are not totally sure that the oxygen in the air is what keeps us alive”. The science is beyond overwhelming here because there’s no reasonable scientific doubt that the warming over the last 50 years is primarily from rising greenhouse gases. It’s the physics, and everything else has been ruled out. Importantly, the math tells us how much extra heat the greenhouse gases are trapping (See image below). John Cook at Skeptical Science has a list of some of the top peer-reviewed papers that also show conclusively that it’s the rising greenhouse gases that are causing the warming.

The science shows virtually all of the warming is from greenhouse gases. Smog is actually holding it back somewhat, while smog particles on snow are making it a bit hotter. From here: https://pubs.giss.nasa.gov/docs/2011/2011_Hansen_ha06510a.pdf

 
The NY Times has a well-written piece quoting Ben Santer, and for the head of the EPA to make such a statement, (when he could ask the top scientists in the country to explain it to him) is nothing less than jaw-dropping. If you’re planning on publicly saying that NASA and NOAA’s top experts, and the AMS, AAAS, AGU, the NSF, Royal Society, and the U.S. National Academies of Science, are wrong about something, you might want to pick up the phone and call an expert first. 

It was not that long ago that some weathercasters and on-air meteorologists were saying things similar to what the EPA head said today, and I’ve been part of a strong effort to make weathercasters aware of how solid the science on this is. We’ve brought in the top experts and provided information on the relevant published science, and once they look at it, the skepticism almost always disappears. You just don’t hear this kind of statement from my fellow meteorologists now, because they understand that there is no science that can back up that opinion, and a whole lot of science that says it is a settled matter.