Calvin on Climate
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Calvin on Climate

The Washington Post Climate Quiz

From <>

The WaPo’s last question, regarding the Siberian permafrost thaw that had revealed a wooly mammoth fossil, provoked me enough to reply:

Which Siberian fossils is quite irrelevant for climate. Mere padding?

Better to use questions that reveal common confusions.

Is emissions an accumulation or a rate*?

How long does it take for natural processes to clean up most of the excess carbon dioxide? a) Until the next good rain, as with smog. b) About a decade, in the manner of methane cleanup. c) Centuries. d) About a thousand years*.

My reply to my own post:

I suppose that I ought to append explanations:

Emissions is a shorthand term carried over from smokestack and tailpipe discharge. It is a shortening of emissions rate: per day, per month; usually per year. The problems arising from such discharges, however, always come from the accumulations that irritate eyes, fog one’s vision, and become smelly enough to annoy — all a consequence of an excess accumulation in the air, not the daily increment.

These are what most people have experienced from air pollution, and they attempt to use it to comprehend the more abstract new problems. But methane and carbon dioxide are both odorless and invisible, and they are far slower for nature to remove. One should never make an analogy between visible and invisible air pollution, as that leads people to think that nature will clean up the carbon dioxide excess as quickly as rain cleans up smog. Emissions reduction succeeds there because of fast cleanup. Not so for carbon dioxide.

And so, my second example asked: Just how slow is nature’s cleanup of our 50% excess of atmospheric carbon dioxide? Since the turn of the 21st century, climate scientists have known that, while half of this year’s contribution to the excess might be gone in another fifty years, the rest has a long tail, with 20% remaining after 1,000 years. That should have caused alarm bells to ring, but we keep prodding along, our leaders saying that a reduction in emissions rate is the right thing to emphasize.

The right thing to have said was that we were going to need to remove the carbon dioxide ourselves and that we were going to have to protect such a big project in the meantime with some shade that reduced the amount of sunlight reaching the earth’s surface.



What’s behind the new extreme weather — and what makes it a climate emergency, requiring that we clean up the 50% excess of CO2 in the air overhead.

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William H. Calvin

President, Professor emeritus, University of Washington School of Medicine in Seattle. Author, many books on brains, human evolution, climate