At this point, almost any violent change in climate will batter our civilization because it is so enormous and makes such a massive demand on the environment. Earth's climate works like a rubber band being stretched and suddenly released. For years, eons even, the stresses slowly build as the chemistry of the air changes. And then, in a matter of a few years or even a few months, there is a shift so vast that we can scarcely begin to imagine it. Earth, it seems, has a powerful regulatory mechanism built into its climate.
Heat increases to a certain point, and then the whole system breaks down.
Cold air comes roaring down from the north, flooding the previously overheated Northern Hemisphere. Suddenly, a new era of cold weather begins. We know, generally, how this happens. But not even science has as yet faced the fact that this change must be accompanied by an absolutely massive release of energy, as earth's climate strives to reorganize itself. In other words, this great shift of climate is almost certainly accompanied by a great storm or series of storms, a weather upheaval outside of contemporary human experience.