Government scientists have cooked up a new concept for how to potentially cool an overheating Earth: Fiddle with the upper atmosphere to make it a bit drier. …That could counteract a small amount of the human-caused warmth. It’s just the spark of an initial idea, said the lead author of a new study. …Known as geoengineering, it’s often rejected because of potential side effects, and is usually mentioned not as an alternative to reducing carbon pollution, but in addition to emission cuts. …Purposely tinkering with Earth’s atmosphere to fix climate change is likely to create cascading new problems, said University of Victoria climate scientist Andrew Weaver. He compared the concept to a children’s story where a king who loves cheese is overrun with mice, gets cats to deal with the mice, then dogs to chase away the cats, lions to get rid of the dogs and elephants to eliminate the lions and then goes back to mice to scare off the elephants.