Global cooling

Global cooling was actually a serious concern in the late 1970’s. There was some evidence and a few vocal advocates claiming that the world was about to dip back into the Pleistocene ice age.

A few degrees of cooling on the global average temperatures and the some of the effects would be as severe as global warming effects . There would be

• shifts in seasonality
• cold snaps
• increased frequency of early and late growing season frosts
• changes to rainfall frequency and intensity
• lower flows in glacier-fed rivers

that would affect crop production in many parts of the world.

Colder weather can be just as uncomfortable to human populations as heat waves , especially in crowded cities in the northern hemisphere where the old and young can be vulnerable.

Sea levels would fall as ice accumulated and the oceans cooled (colder water takes up less space than warmer water, the opposite effect of sea level rise). This would reduce the risk of inundation in low-lying coastal areas but could strand important port and shipping infrastructure.

As sea levels fall there would be a temptation to use any new land for agriculture. These areas would be vulnerable to climate reversals and storm surges. We would be no better under significant cooling than we would be with significant global warming.

And in this statement we have the essence of the climate conundrum. It is the change, both as magnitude and speed, in climate that is the problem for us.

Climate changes, it always has and always will.

Cooling will be a feature of this change at some point in the future, but probably not anytime soon.

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