Open Mind

Days of Wine and Roses

November 11, 2006 · 2 Comments

There’s a new book out, Unstoppable Global Warming-Every 1500 Years, by well-known global warming denialists Fred Singer and Dennis Avery. You can read the press release here. The book claims it “Debunks Greenhouse Fears and Points to Natural 1,500-Year Warming Cycles”

One of the prominent evidences they give against the reality of current warming is the inability to grow wine grapes in modern England.

“The Romans wrote about growing wine grapes in Britain in the first century,” says Avery, “and then it got too cold during the Dark Ages. Ancient tax records show the Britons grew their own wine grapes in the 11th century, during the Medieval Warming, and then it got too cold during the Little Ice Age. It isn’t yet warm enough for wine grapes in today’s Britain. Wine grapes are among the most accurate and sensitive indicators of temperature and they are telling us about a cycle. They also indicate that today’s warming is not unprecedented.”

Not yet warm enough for wine grapes in today’s Britain! Sounds pretty convincing, eh?

The trouble is, it’s just not true. Don’t take my word for it — get the opinion of English Wine Producers. While you’re at it, congratulate them on winning the award for “best sparkling wine” at the International Wine and Spirit Competition two years running. Fact is, not only are wine grapes growing in England today, it’s become an industry that’s flourishing as never before.

The “no vineyards in England” argument has been used many times to support the idea that modern temperatures aren’t at all that warm. Problem is, those who use the argument don’t have their facts right. But it seems to me that there’s simply no excuse for this; it’s not that hard (not at all hard, in fact) to get correct information on this topic. Try it yourself — google “english wine” and see what turns up. I found a wealth of information, including a nice History of English wine-making. And I didn’t even have to leave my chair.

In a previous post, I pointed out another way to be deceptive about earth’s temperature history: leave out the data that contradicts your desired conclusion. I’ve also seen works by denialists that actually change the data to make their case. I’ve seen graphs compared side-by-side to give the impression that they show identical behavior, in which you have to look very closely to notice that the scale of one graph goes from -1 to +1 while the scale of the other graph goes from -0.02 to +0.02. All this sleight-of-hand makes it immensely more difficult for the general public to evaluate the strength of the arguments. There are a handful of legitimate climate scientists who dispute that global warming is caused by human activity (a very small handful, to be sure). But the deceptive tactics of most denialists cast a pall over their efforts.

So how can the non-expert reader sift through the chaff to get to the wheat? I can offer some advice about how to tell the difference between a legitimate, honest statement (confirmation or denial) about anthropogenic global warming, and a deliberately deceptive and/or excessively sloppy piece of misinformation.

1. Look for sources. If you read articles on RealClimate, you’ll notice that the posts by the moderators (and many of the comments too) are littered with links and references, so you can get information from the original source and confirm things for yourself. It’s easy to make claims, but claiming doesn’t make something true. Articles that give sources for information are more likely (but not certain!) to be correct. Also, give some thought to the reliability of the information. Peer-reviewed scientific journals are the most reliable (but again, not infallible!); put more trust in Geophysical Research Letters, less trust in Time and Newsweek, and don’t get your climate information from The National Enquirer.

2. Check basic facts. I recently saw a piece that flatly stated that the southern hemisphere hasn’t warmed at all in the last 25 years. Again, a little web research will quickly reveal that this just ain’t so. I often hear the claim that moderate-to-large volcanic explosions like Mt. Pinatubo and Mt. St. Helens injected more CO2 into the atmosphere than all human activity since the beginning of civilization. A little research reveals that CO2 emissions from volcanos like Pinatubo and Mt. St. Helens are measured in millions of tons, while emissions from human activity in one year in the U.S. alone are measured in billions of tons.

3. Look for consistency. There’s a denialist website that makes many claims, including these two: 1. global warming isn’t happening; 2. global warming will make the future world better by lengthening the growing season and reducing the costs of severe winter. Unfortunately, these two claims contradict each other. If global warming isn’t happening, how will it make the future world better?

4. Beware selective use of scientific data. Some works claim that there’s no relation between CO2 and climate over the last 500 million years — that CO2 levels were several thousand ppm in the very long distant past but temperatures were only modestly higher than today. They also claim that temperature reconstructions of the last 1 or 2 thousand years — like the “hockey stick” — are utterly false, based on naive, mistaken science. Odd that they deny our ability to reconstruct past temperature a mere thousand years ago, but put absolute faith in temperature and CO2 estimates half a billion years ago.

5. Ask questions and check the original sources. Someone claims that the recent National Academy of Sciences report rebuked the hockey stick? Go to RealClimate and ask their opinion. Better yet, download the report and read it for yourself.

6. Distrust those who have “all the answers”. If you read RealClimate regularly (and I do), you’ll notice that they often make statements like, “We don’t really understand cloud formation well enough,” and “There’s some uncertainty in the effect of sulfate aerosols.” Most denialist websites never admit uncertainty or ignorance, instead they tend to speak as though their conclusions were absolute, undeniable truth.

Climate science is complex. It’s not easy, even for those who have dedicated a lifetime to its study. It’s far more difficult for lay readers, especially with so many deliberate efforts to cloud the issue. There’s no sure-fire way to tell truth from falsehood, but with common sense, a healthy skepticism, and a willingness to look things up for yourself, you stand a much better chance of making an intelligent decision.

Categories: Global Warming

2 responses so far ↓

  • unitedcats // November 11, 2006 at 7:09 am

    Well put, sadly too many people search for the facts that fit their theory, and not vice versa. All the logic in the world won’t convince them, it’s like arguing with Creationists. Still, one must try I suppose, great information here, I will put it to good use.


    [Response: Thanks. I try to remember that it’s worth the effort, because even if the advocate of the contrary view is entrenched, there are usually lots of other people listening. Although — there comes a point when one should not “feed the troll.”]

  • Laura // November 12, 2006 at 3:54 am

    It’s easy to make claims, but claiming doesn’t make something true.

    It’s like that old kids’ joke: if you call a tail a leg, how many legs does a dog have? The answer, of course, is four; calling a tail a leg doesn’t make it one.

    Good work as always. Keep fightin’ the good fight.

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