The Washington Post ran a story recently with this howler of a headline: “Global Warming is ‘Real,’ Report Finds.” The Post could just as easily have gone with the blockbuster revelation–”Earth Revolves Around Sun, Report Finds”–and it would have been as newsworthy.
As anyone who has spent more than three minutes reading about this issue knows (my fingers are callused from typing these words), the question is not if the Earth has warmed, the question is why the Earth has warmed. Is industrial society the culprit of planet-wide warming?
Science cannot tell us what our national policy toward environmental issues like global warming should be. But science is essential for helping us decide if it is a problem in the first place. What to do about it, if anything, is a political question. But we can hardly expect wise political decisions if the popular reflection of climate science does not even distinguish between real and imaginary scientific uncertainties.
The best way to sort out the genuine science of climate change from the science-lite version handed to us by advocacy groups and others would be to sit down with a group of experts and ask them elementary questions about this huge controversy. If we could gather a panel of specialists like this together, we would probably want to ask them questions such as: What is the greenhouse effect? Has the Earth really warmed and, if so, is the greenhouse effect to blame? How accurate are the computer models used to forecast the Earth’s climate? Will global warming cause floods, spread diseases, and produce other disasters?
That conversation is essentially what the Marshall Institute presents in its new publication, A Guide to Global Warming: Questions and Answers on Climate Change.
This booklet brings the experts on climate change to the reader. The Institute provides concise and easily understood answers to nineteen questions on the science of climate change. But the Institute has done more than give answers to questions; it also gives the reader references to the peer-reviewed scientific articles that back up these answers. Students, teachers, and high school debaters will find a gold mine of information, key source materials, and data necessary to understand the global warming debate.
Take the climate forecasts as an example. To the question “Are computer simulations of the Earth’s climate accurate?” the Guide provides a simple answer: No. But this one-word reply is supported by six paragraphs of text and seven references to the key articles in the scientific literature on computer modeling of the climate.
The Guide explains why the computers do such a poor job of predicting climate change. Doubling the amount of carbon dioxide in the atmosphere will add energy to our climate system, about 4 watts per square meter. But this amount pales in comparison to huge uncertainties about the other forces that affect our climate. Uncertainty in the climate effects of clouds alone can introduce 25 watts per square meter uncertainty into the computer’s calculations. In other words, what we don’t know about the forces changing our climate dwarfs what we do know.
We often hear concerns about how our use of coal and oil for energy are going to cause major shifts in our climate over the next century. But as the Guide shows, the Earth’s climate changed dramatically–from cold to warm and back again–centuries before humans could have had any influence on the climate. The shift between glacial and interglacial conditions, for example, can take place in less than a thousand years and sometimes in as little as a few decades. These huge changes–changes that far exceed anything envisioned by even the most apocalyptic global warming scenarios–stem from wholly natural climate forces.
Those who believe that humans are causing a calamitous change in the Earth’s climate frequently assert there is a “consensus” among scientists that we must reduce our use of fossil fuels or face an Earth on fire. With cool facts and key references to the scientific journals, the Guide shows this claim to be simply untrue.
Jeffrey Salmon is executive director of the Washington, DC-based George C. Marshall Institute.