The Public Policy

Okay Coral

Our oceans' coral reefs have survived a lot worse than a slight increase in global temperatures.

By 8.2.06

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Weeks after the National Science Foundation released a report about the connection between increases in atmospheric carbon dioxide and the acidity of the oceans, doomsayers continue to prophesy that global warming will kill the coral reefs off our picturesque Florida coast.

The NSF study, released with two other federal research entities and entitled "Impacts of Ocean Acidification on Coral Reefs," landed with a thud, and it is remarkable how the press has received it. Writers have editorialized about it, literally with one voice, without any critical fact-checking. In a July 11 editorial, the editors of the Cincinnati Post wrote, "This report is a fraction of the available evidence indicating anthropogenic climate change....The evidence is clear and convincing. The global-warming critics are neither." On July 12, the Albuquerque Tribune, in its own in-house editorial, printed the same words (without attribution).

It could have done something more original and scrutinized the NSF report. There's a major problem with it, right at the beginning. Its first paragraph states correctly that, as a result of the burning of fossil fuel and other activities, atmospheric carbon dioxide concentration is rising. From there, however, the report loses its way. "Rates of increase," it says, "have risen from 0.25% [per year] in the 1960s to 0.75% [per year] in the last five years."

Really? The standard reference for atmospheric carbon dioxide concentration is that registered at Mauna Loa Observatory, beginning in 1958. The average rate of change in the 1960s was 0.30% per year, and in the last five years, it was 0.55%. This last value is not statistically distinguishable from the average rate for the past 25 years. The real change from the 1960s to the last five years is 0.25% per year, while the NSF-sponsored report gives it as twice that.

The precise figure is important, because the rate of increase of atmospheric carbon dioxide is directly related to the amount of warming it creates and to changes in the acidity of the oceans; computer models using a carbon dioxide increase rate twice that which is observed show twice as much warming. And that is precisely what has occurred: there are now four separate, taxpayer-supported reports "intercomparing" the dozens of climate models for global warming that have evolved in recent years. Each one uses a carbon dioxide increase of 1% per year, or twice the real rate. Ever wonder why they predict so much warming?

It gets better (worse). The coral report then states that "The current atmospheric CO2 concentration...is expected to continue to rise by about 1% [per year] over the next few decades."

"Continue"? The average increase for the last decade was 0.49 per year, for the decade before that was 0.42%, and for the decade before that was 0.43%. Again, about half of what the report expects to "continue."

The current concentration of carbon dioxide in the atmosphere is about 380 parts per million. Before we industrialized -- back when life expectancy was in the 40s -- the concentration was about 280.

Fewer than 100 million years ago, or 400 million years after corals first arose, the carbon dioxide concentration was a bit less than 3,000 ppm. Around 175 million years ago it was pushing 6,000. If there was that much more carbon dioxide around, the oceans would have been that much more acidic, which would have killed the corals. And yet they lived.

How does the report take this problem into account? It balances the increase in acidification that these concentrations of carbon dioxide would bring about with some countervailing change in its opposite, alkalinity. So the report speculates that "ocean alkalinities could have been higher during periods with high CO2 levels." (Emphasis added.)

Then there's the problem of identifying a definite decline in corals. The report says that it is "difficult" to find this effect, and that "on average" it does not exist, because the rates of coral growth are controlled by many other factors that are apparently obscuring their decline.

How on earth did all of this make it through peer review? Or do we no longer care enough to get the facts right before expressing opinions under the mantle of scientific authority?

To many editorialists, when it comes to global warming, facts don't matter. But here are a few: corals have been around for half a billion years, on a planet that was much, much warmer, had much more carbon dioxide in its atmosphere, got hit by an asteroid or two, experienced ice ages and is now in the midst of a slight warming trend. You can bet that they'll be around a long time after humans have come to the end of the evolutionary road.

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