Posted by Dawn-Ann on June 6, 2009
It’s snowing today in Calgary. Yes, in June. And while it’s true Calgary has seen snow in each month of the year (sometimes all 12 months of a single year), it took me by surprise and got me thinking.
I’d heard rumours about a coming ice age and the last couple of winters and springs have definitely reminded me more of the ones I experienced growing up in northern British Columbia. So I performed a quick Google search and did find that folks are talking about it.
Climate and temperatures go through long cycles of heating and cooling (with or without man’s CO2 emissions) and ice ages are more the norm. Between ice ages the planet often experiences brief periods of “interglacial” time, where temperatures are balmy and warm. They are usually relatively short-lived and have been known to get much warmer than what we have recently been experiencing. Then the cold and snow starts to settle back in.
Five hundred million years ago, carbon dioxide concentrations were over 13 times current levels; and not until about 20 million years ago did carbon dioxide levels dropped to a little less than twice what they are today.
It is possible that moderately increased carbon dioxide concentrations could extend the current interglacial period. But we have not reached the level required yet, nor do we know the optimum level to reach.
[Source: The Coming of a New Ice Age]
The question is not if we’ll be plunged into another ice age, but when. Thankfully, these long cycles take tens of thousands to hundreds of thousands of years to run their course. No point in migrating to warmer climes just yet. Well, unless you want to.
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