Significant warming has taken place quite often in the past, as well as climatic cooling. (c3headlines.com)
The first is that there is independent evidence for climatic cooling in Greenland as the MWP transitioned to the LIA. (wattsupwiththat.com)
Nuclear winter is the severe and prolonged global climatic cooling effect hypothesized [1][2] to occur after widespread firestorms following a nuclear war. (mustelid.blogspot.ru)