meaning:
Ancient global warming rocked cradles of civilisation.
Enviwacos never use term "global warming" applied to the past. Global warming can happen only now and in the future. Global warmings of the past are "climate changes".
Ahem - if you read Brooks' paper you'll see that he's claiming the development of "civilization" was associated with a cold, arid period. "Climate change" just means a change in the climate - hotter or colder. In this case it's colder. Can't people say anything about climate change without being accused of being "envirowacos", even when it's got nothing to do with global warming or the argument about what's going on today? Or is no discussion of climate change permitted at all, in case it lends credibility to all those greeny lefty types who claim it's happening and is a problem?