Friday, February 2, 2007

What if global warming is a good thing?

By Donald Sensing

Reposted from donaldsensing.com from February 2007, impelled by Harold Ambler's piece on The Huffington Post, "Mr. Gore: Apology Accepted."

Several years ago I was conversing with a man whom I've known for many years. The talk turned briefly to global warming (who knows why) and I still remember the pithy point he made: "No one has ever explained why it's supposed to be a bad thing."

And, really, I have never heard that explanation, either. Oh, I know all about the presumption of rising sea levels, but those estimates are all over the place; I've read over time that the average sea level will rise from a couple of inches to many feet. The latter, of course, could be true only if there is total melting of both polar caps, but you have to wade through the fine print to see that. The only downside I have ever read about rising sea levels is that a large percentage of the earth's population lives near the sea and could be flooded out. Which might be true if the ocean rose by many feet, not a few inches, and if it rose very suddenly, not over a period of many decades. Even so, I will not dispute that significantly rising sea levels could turn out to be a bad thing, bearing in mind, always, that the key is "how much." The IPCC's latest estimate is 7-23 inches, which frankly does not seem an unmanageable amount to adjust to over the next 100 years.

Anyway, I commend to you J. R. Dunn's essay,"Resisting Global Warming Panic," expecially his exposition of the "medieval warm period, more commonly known as the Little Climatic Optimum (LCO), a period stretching roughly from the 10th to the 13th centuries, in which the average temperature was anything from 1 to 3 degrees centigrade higher than it is today."

* How warm was it during the LCO? Areas in the Midlands and Scotland that cannot grow crops today were regularly farmed. England was known for its wine exports.

* The average height of Britons around A.D. 1000 was close to six feet, thanks to good nutrition. The small stature of the British lower classes (and the Irish) later in the millennium is an artifact of lower temperatures. People of the 20th century were the first Europeans in centuries to grow to their "true" stature - and most had to grow up in the USA to do it.

* In fact, famine - and its partner, plague -- appears to have taken a hike for several centuries. We have records of only a handful of famines during the LCO, and few mass outbreaks of disease. The bubonic plague itself appears to have retreated to its heartland of Central Asia.

* The LCO was the first age of transatlantic exploration. When not slaughtering their neighbors, the Vikings were charting new lands across the North Atlantic, one of the stormiest seas on earth (only the Southern Ocean - the Roaring 40s - is worse). If you tried the same thing today, traveling their routes in open boats of the size they used, you would drown. They discovered Iceland, and Greenland, and a new world even beyond, where they found grape vines, the same as in England.

* The Agricultural Revolution is not widely known except among historians. Mild temperatures eased land clearing and lengthened growing seasons. More certain harvests encouraged experimentation among farmers involving field rotation, novel implements, and new crops such as legumes. While the thought of peas and beans may not thrill the foodies among us, they expanded an almost unbelievably bland ancient diet as well as providing new sources of nutrition. The result was a near-tripling of European population from 27 million at the end of the 7th century to 70 million in 1300.

* The First Industrial Revolution is not widely known even among historians. Opening the northern German plains allowed access to easily mined iron deposits in the Ruhr and the Saarland. As a result smithies and mills became common sights throughout Europe. Then came the basic inventions without which nothing more complex can be made - the compound crank, the connecting rod, the flywheel, followed by the turbine, the compass, the mechanical clock, and eyeglasses. Our entire technical civilization, all the way down to Al Gore's hydrogenmobile, has its roots in the LCO.

But temperatures started crashing in the late 13th century, after which came the Great Plague, killing a third to half the population of Europe.

Folks my age and maybe a little younger can remember when the Environmental Apocaplypse was not global warming but global cooling. So let us suppose two things: first that global warming really is occurring and human attention to it can reverse it, and second, that we do reverse it. Are we then to agree that a cooler earth really is in our best interests? Why?

I've always kind of suspected that underlying much of environmentalism is a desire for the impossible: stasis. For the earth will either get warmer or cooler, but it definitely won't stay the same. Even if everyone were to agree that the globe really is warming, can we please see some scientifically-sound documentation that it is worse than the alternative?

Update: Okay, nothing can be done to reverse global warming, according to the IPCC's latest report.

The report said no matter how much civilization slows or reduces its greenhouse gas emissions, global warming and sea-level rise will continue for centuries.

"This is just not something you can stop. We're just going to have to live with it," Trenberth said in an interview. "We're creating a different planet. If you were to come back in 100 years' time, we'll have a different climate."

Scientists worry that world leaders will take that message in the wrong way and throw up their hands, Trenberth said. That would be wrong, he said. Instead, the scientists urged leaders to reduce emissions and also adapt to a warmer world with wilder weather.

There's no arguing with the proposition that we should prepare for the effects of warming if we know it's coming. But I would submit that the models are still way too much inexact to know exactly what to prepare for. There's a 300 percent difference across the range of sea level increases the IPCC predicts. Also, the IPCC "predicted temperature rises of 2-11.5 F by the year 2100." Again, a very large variation.

And yes (before you leave a rancid comment!) , I have read articles explaining the prospects of increased desertification and other warming-related effects, but the thrust of my question, might it turn out to be a good thing, is oriented not in microclimes here and there, but on the net overall effect worldwide. For every hectare turned to new desert, would there be a hectare turned to verdancy, especially land newly useful for agriculture when it wasn't before? Is there really a downside to the extension of the growing season is more northern and southern latitudes? After all, certain commercial grains can now be grown in Iceland, which couldn't be done only 20 years ago. In the literature I've read on warming, potential positive effects seem to either be ignored or glossed over. If you know of essays that engage both sides of the question, please do post links.

Again, the issue cannot be maintaining a climatic status quo, since that wasn't the case even before humanity's earliest known ancestor, Ardipithecus ramidus kadabba, walked around more than six million years ago. The earth "rests" only briefly between periods of cooling then warming. So it's warming now. Is that worse than cooling? Answering that question might give some balance to the political debates on the issue.

No comments: