It's almost summer in the northern hemisphere, and that can only mean one thing — it's time for global-warming (search) activists to sound the alarm.
Though temperatures obviously rise due to natural causes during the summer, global-warming activists like to take advantage of this time to dramatize their cause.
This year is no exception, as global-climate worry-warts gathered this week in Washington, D.C., at a conference sponsored by the American Association for the Advancement of Science (search) to convulse about the Bush administration's refusal to embrace the Kyoto global-warming treaty (search) and clamp down on emissions of greenhouse gases such as carbon dioxide.
Speakers at the conference said they hoped to convince the U.S. public to pressure politicians into policy changes.
"In this country, it depends a lot on what happens in the next election," geochemist Daniel Schrag of Harvard University told Reuters. "I don't think we can expect to change the minds of this administration in the next couple of months."
Schrag then went on to provide alarmist factoids about the build-up of carbon dioxide (search) in the atmosphere. He said the current concentration of carbon dioxide in the atmosphere is 380 parts per million — higher than it has been for at least the past 430,000 years.
"In the next 100 years, unless immediate action is taken, carbon-dioxide levels will rise to between 800 and 1,000 parts per million. The last time carbon dioxide was that high was during the Eocene (search), 55 to 36 million years ago," Schrag told Reuters.
At that time, he said, "palm trees lived in Wyoming, crocodiles lived in the Arctic, Antarctica was a pine forest and sea level was at least 300 feet higher than today."
But is atmospheric carbon dioxide all that really separates us from coconuts in Laramie and Inuit crocodile wrestling?
Hardly. About 95 percent of the greenhouse effect (search) — the atmospheric warming due to the trapping of solar energy that makes life possible on Earth — is due to water vapor, 99.999 percent of which is of natural origin.
The other 5 percent of the greenhouse effect is due to carbon dioxide, methane, nitrous oxide and other miscellaneous gases.
Although carbon dioxide is the most dominant of these gases by volume, comprising about 99.4 percent, the other gases trap more heat. So the contribution of carbon dioxide to the 5 percent of the greenhouse effect not due to water vapor is much less than 99.4 percent — it's about 72 percent.
Carbon dioxide, therefore, is responsible for roughly 3.6 percent of the greenhouse effect (5 percent, representing the percentage of the greenhouse effect not due to water vapor, multiplied by 72 percent, representing the percentage of that 5 percent due to carbon dioxide).
But carbon dioxide is produced both naturally and by humans. About 97 percent of atmospheric carbon dioxide is natural, in fact. Only about 3 percent is from human activity.
That means that only about 0.11 percent of the greenhouse effect (that is, 3 percent of 3.6 percent) is due to human releases of carbon dioxide into the atmosphere.
Put another way, about 99.89 percent of the greenhouse effect has nothing to do with carbon-dioxide emissions from human activity.
Factoring in the other greenhouse gases, the total human contribution to the greenhouse effect is about 0.3 percent. In other words, about 99.7 percent of the greenhouse effect is due entirely to nature.
When you consider that the greenhouse effect contributes about 60 degrees Fahrenheit to the Earth's average temperature (which would be about zero degrees Fahrenheit without the greenhouse effect), it doesn't really seem like atmospheric carbon dioxide levels — even if they triple or quadruple because of human activities — are all that important to global climate.
If the carbon dioxide-emissions reductions called for by the Kyoto global warming treaty were implemented, human greenhouse contributions would be reduced by about 0.03 percent. Atmospheric physicist Fred Singer says this would have an "imperceptible effect on future temperatures — one-twentieth of a degree by 2050."
As the Kyoto protocol would require cutting energy use by about 30 percent by 2010 — necessarily causing inestimable negative economic consequences — it's easy to see why U.S. politicians can't run away from the Kyoto protocol fast enough.
It seems we don't need to worry about coconuts in Wyoming so much as the nutty global warmers who meet every summer in Washington, D.C
Steven Milloy is the publisher of JunkScience.com, an adjunct scholar at the Cato Institute and the author of Junk Science Judo: Self-Defense Against Health Scares and Scams (Cato Institute, 2001).