This is a picture of the atmospheric temperature in the lower troposphere and in the lower stratosphere. The stratosphere is higher up than the troposphere. The red and orange means "More hot." What this image shows is that greenhouse gasses are trapping heat in the atmosphere.
The image comes from this article, which discusses new modeling systems that allow researchers to create an even clearer picture of the fact that the gasses that humans have pumped into the atmosphere over the last hundred years are the thing that's causing climate change, not -- as they explicitly point out -- from stuff like volcanoes or natural cycles of sun-heat:
“After removing all global mean signals,” the authors write, referring to natural changes like volcanic eruptions and changes in the brightness of the sun, “model fingerprints remain identifiable in 70 percent of the tests involving tropospheric temperature changes.”
In plain English, that simply means that the warming of the troposphere and cooling of the stratosphere can’t be explained in any other way than by the heat-trapping effects of human-generated greenhouse gases. “It was surprising to me how large the signal was,” Santer said.
This is also, they point out, consistent with the whole constellation of evidence that climate change is human-caused:
This is only one of the fingerprints scientists expect to see in a human–influenced climate, moreover. “In the past we’ve looked at ocean surface temperatures changes in hurricane-forming regions, patterns in atmospheric pressure; rainfall patterns, and changes in Arctic sea ice,” Santer said.
All of these and more can be identified more easily and clearly with the new models.