THE CURRENT WISDOM is an Advisory service whose purpose is to acquaint readers with items of interest appearing in the scientific literature. Particular attention is paid to recent pulbications and presentations; however, we occaisionally hearken back to the Wisdom of the ages.
The Wisdom is an attempt to balance the popular perception of important issues relating to our climatic environment. Several scientific papers or public presentations occur each quarter that may not receive either the public exposure or the interpretation that is commensurate with their importance.
Finally, we note that the Wisdom often spins against some
popular grain. Webster defines "wise" as "evidencing or hinting at the
possession of inside information."
Some people have clucked that the U.S. greenhouse gas emission proposals unveiled at the big United Nations confab in Kyoto were sort of like an Evelyn Waugh novel, where no group of anyone comes out unscathed. Actually, the Administration program is highly reflective of the political and scientific divisions swirling about global warming and the greenhouse effect. And, contrary to some assertions, when the numbers are flashed through, the response is commensurate with our confusion - i.e. the current proposals really won't do much of anything about global warming, even if one was a diehard believer in the prevailing gloom-and-doom.
What we've done here is to presume that the entire world goes along with the U.S. proposal to reduce emissions to 1990 levels by 2012 (the "official" version says "2008 to 2012," but we think that means "2012"). Now, no one expects this. But, for the sake of argument, let's go along with the fantasy.
Here we scale the recent version of the new National Center for Atmospheric Research climate model, as unveiled in public for the first time last May in Science magazine. This model has the distinction of actually tracking the (lack of big) warming of the last 100 years pretty well. Of course (surprise!) this constrains it to not predicting a big warmup in the next century, either. But it does produce some heating‹about 1.4°C additional if the current exponential rise in effective carbon dioxide concentration (0.7%/year) is maintained.
What happens if we input the Administration scenario and everyone else agrees to do the same? The problem is that, by merely returning emissions to 1990 levels, the increase in effective atmospheric carbon dioxide* that occurred in 1990 (about 3.08 parts per million per year [ppm]) continues for every succeeding year. The effective concentration in the atmosphere in 2047, fifty years from now, is 655ppm if we do nothing, and 618ppm if the entire world goes along with us.
This difference - 37ppm - gives a "savings" in global warming of 0.13°C over the next 50 years. The difference will be impossible to detect from ground based temperature records, although it should show up in satellites, which are more accurate.
*"Effective" carbon dioxide takes carbon dioxide plus all the other human greenhouse gases and expresses them as the equivalent in carbon dioxide.
As noted in our introblurb, the purpose of the Current Wisdom is to bring to the fore some interesting item that didn't make it into the Daily Blatt. The independent market research firm, American Viewpoint, recently polled the State and Regional Climatologists on the subject of global warming. 36 individual responded, which is more than half of the possible sample available - a very respectable number, for any poll. Two-thirds of the respondents have been climatologists for more than 10 years. 17 percent identified themselves as liberal, 58 percent as moderate, and 20 percent as conservative.
The results were a bit of stunning contrast to the "popular vision" that scientists all agree the world is coming to an end or something like that. When asked:
Do you agree or disagree with the following statement?: "The overwhelming balance of evidence and scientific opinion is that it is no longer a theory but now a fact that global warming is for real. There is ample evidence that human activities are already disrupting the global climate."
58% of the respondents disagreed.
Our favorite has to do with those gloomy-doomy computer models that seem to be serving as the basis for both policy and fear.
On a scale of one to 10, with one being not at all accurate and 10 being extremely accurate, please tell how accurate you believe computer modeling to be in terms of forecasting climatic conditions 50 to 100 years into the future."
We've graphed this one up for you. Greater than 80% of the respondents graded the computer forecasts in the bottom (inaccurate) half of the scale. The most oft-given score was a three - which is somewhere around a C- or a D+ on the academic scale.
What about severe weather? Everyone knows things are getting worse. Here's the survey question:
"Have weather events in the past 25 years been more severe or frequent than in other periods in your state's history?"
72% of the respondents said NO. Remember that the State Climatologists are the folks with data all over their hands every day as they answer everyone's weather questions.
19% of the respondents said "yes", though. So American Enterprise asked only those who said that weather was becoming more severe, if this was caused by global warming. Of those yes-people, a remarkable 78% said "No, it wasn't planetary heating."
While we are crabbing about El Niño hype, along comes a big article by Richard Fairbanks and a zillion coauthors in the journal Coral Reefs about our second favorite climate whipping-boy.
People have speculated back and forth--generally on the basis of little or no information --as to whether El Niños have changed very much as the earth's climate has changed. Last year, D.H. Sandweiss noted in Science that scattered archaeological evidence from Peru indicated that when the earth was 1-2¡C warmer, some 4,000-7,000 years ago, El Niños were fewer and further between.
Archaeological data is notably subjective, coming from people and being interpreted by people. Dumb animals--and corals are among the dumbest--don't have subjectivity problems. And corals keep very good records of water temperatures as El Niños slosh back and forth across the Pacific.
Here's the bad news from the Corals--El Niños have been becoming stronger in the 20th century. The good news--they are just returning to levels observed around 250 years ago. Most everyone believes that the 18th century was quite a bit colder than the 20th. So the balance of evidence is the El Niños seem to come and go, whether or not the globe is warming or cold.
Fairbanks, R.G., et al., 1997. Evaluating climate indices and their geochemical proxies measured in Corals. Coral Reefs 16, S93-S100.
Sandweiss, D.H., et al., 1996. Geoarchaeological evidence from Peru for a 5,000-year b.p.
onset of El Niños. Science 273, 1531-1533.