Saturday, May 18, 2013

Does Anthropogenic Global Warming Mean That We Are Really "Screwed"?

I haven't had much to say about the whole global warming debate, partly out of not wanting to reveal my vast ignorance, but also because I've suspected that I'm not alone in being this ignorant. A recent article in The Atlantic proves my point. It's entitled, We're Screwed: 11,000 Years' Worth of Climate Data Prove It.

In the article they provide two graphs: One showing average temperatures going back 2,000 years, and one showing average temperatures going back 11,000 years. The second graph is the more interesting. It shows a gradual rise in temperatures until about 7,000 years ago, and then a gradual decline in temperatures until about a hundred years ago, when temperatures started to rise rapidly.

Now I'm willing to believe that the reason for the rapid rise in temperatures is anthropogenic greenhouse gases. What I wonder about is the assertion that this means that we are "screwed." What I just learned myself is that we are currently living in an ice age that started about 2.6 million years ago. The last glacial period ended about 12,500 years ago. It lasted about 100,000 years. And apparently we've been in a cycle of glacial periods lasting for about 100,000 years, followed by warm periods lasting about 10,000 to 15,000 years during much of our current ice age. So when I look at that second chart, I wonder, "Were we headed into another glacial period?  Did our anthropogenic greenhouse gases save us from catastrophy?"  For one thing I do  know is that we do not want another glacial period. The human race would certainly be "screwed" then.

What isn't clear to me is that continued output of greenhouse gases will screw us, or screw us as badly as a glacial period. For example, some scientists think that we are about to experience a reduced amount of sunspot activity and that we will have another little ice age. I don't know if they're right, or if they're just payed employees of oil companies, spewing more propaganda. I do know that reduced growing seasons is something we don't want, especially with seven billion mouths to feed. Compared to the risk of global cooling, tell me again why global warming is so much worse.

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