The waves of the tsunami had hardly receded before environmental alarmists linked the tragedy to . . . global warming ! One newspaper, the Independent , quoted a British environmental activist saying that "here again are yet more events in the real world that are consistent with climate-change predictions." On New Year's Eve, Sir David King, Britain's chief science adviser and top climate-change fanatic, told the BBC, "What is happening in the Indian Ocean underlines the importance of the Earth's system to our ability to live safely. And what we are talking about in terms of climate change is something that is really driven by our own use of fossil fuels." It was almost as if environmentalists were trying to vindicate Michael Crichton's scenario in State of Fear, where eco-terrorists attempt to start a tsunami in the Pacific to scare people about global warming.
Although a few environmental activists have attempted to back away from these ludicrous and embarrassing statements, the predictability with which climate change was linked to a geological event shows the difficulty of taking climate change seriously. Climate change is a legitimate issue, but between the shabby way environmentalists and the Left exploit it, and the faulty record of so many past predictions of the eco-apocalypse, deep skepticism remains the sensible default position.
For climate alarmists, climate change has become what logicians call a "non-falsifiable hypothesis." Every weather anomaly is said to be a sign of climate change. After the near-record January 1996 blizzard hit the northeastern U.S., Newsweek ran a cover story attributing the storm to climate change. A year later, when an unusually warm winter led to early snow melt and floods in the upper Midwest, Vice President Al Gore and others attributed it to climate change. And the three hurricanes that struck Florida in close succession last summer were a bonanza for the climate-change chorus, even though serious climate scientists readily admit that ascribing today's extreme weather events to global warming is scientifically insupportable. In fact, the intensity of hurricanes and cyclones has diminished slightly over the past 30 years.
Even the catastrophic scenarios painted by enthusiasts clash. In one extreme case, the Greenland ice sheet and much of the polar ice caps could melt, raising the global sea level by as much as 30 feet, inundating billions in coastal areas. (Keep in mind, though, that such a scenario would take decades to play out, unlike a tsunami.) But hold on: A variant of catastrophe theory holds that warming might cause the Greenland and polar ice sheets to thicken and bring on a new ice age--the scenario of the movie The Day After Tomorrow. Incidentally, the sea level would fall by several feet, creating new opportunities for beachfront development.
These competing scenarios have some theoretical plausibility, but the inability of the scientific community to assign a probability estimate to either a temperature increase or the effects of such an increase--regionally as well as globally--shows how limited our climate knowledge remains. Although computer climate models are being constantly refined and improved, their compound uncertainties and blind spots make it impossible to know the probability of any future outcome. For all their sophistication, the models have not even been able to "backcast"--i.e., match up greenhouse-gas emissions with the climate record--for the last 30 years.
The (Black) Art of Prediction
Precisely because the computer climate models are plodding along, unable to deliver the goods, environmentalists latch on to any event as proof that global warming is well under way, even if the evidence is thin or is contradicted by other evidence. Gregg Easterbrook's first rule of environmental doomsaying is that predictions should be dated far enough in the future so that no one will remember them when they fail to occur. Specificity was the error of Paul Ehrlich's prediction that millions would starve in the 1970s and Jimmy Carter's Global 2000 report, many of whose specific predictions for the year 2000 were wrong by an order of magnitude. Catastrophic global warming over the next 100 to 200 years neatly solves this problem. It's the ultimate "for the children" issue.
But the hyping of every possible scare that comes down the road -- such as melting glaciers, shearing polar ice sheets, flowers blooming earlier than usual, animals migrating north, hurricanes, European heat waves, northeastern U.S. cold snaps, and so on -- is backfiring on environmentalists, and the issue is losing steam. The annual Gallup Poll on the environment last spring found declining public interest in global warming. "Last year at this time," the firm's Lydia Saad wrote, "Gallup reported that global warming was 'a bit of a yawn' to most Americans. Today, one might say the public is practically dozing . . . Global warming ranks near the bottom of the list of specific environmental issues for which Gallup measured public concern." Unable to persuade the public, environmentalists are increasingly looking for ways to file lawsuits to stop climate change.
What do we actually know? The earth's temperature has risen about 1 degree Celsius over the last 100 years. That's where the agreement ends and the arguments begin. It is not clear whether this increase has harmed anyone (in fact it may have had net benefits); the Inuits of the Arctic north complain they have been hurt, but they drive their snowmobiles and SUVs from their heated homes to the courthouse to file their lawsuits. Some of the increase may be man-made, but much of it may be a natural warming trend stemming from the "little ice age" between the 14th and 19th centuries. Some scientists believe the warming may have more to do with deforestation and other land-use trends than greenhouse gases. There is no consensus on this point.
Evidence that the last few decades were the warmest in the last 1,000 years has recently been discredited. The so-called "smoking gun" of man-made global warming was the famous "hockey stick" graph, which showed a flat temperature record taking a noticeable upward bend in the last generation. It has been demolished for statistical shoddiness. The "medieval warm period" before the "little ice age" may have been as warm as, or even warmer than, today.
The emergence from the "little ice age" explains why many glaciers are retreating. It is usually forgotten that this retreat began in the 19th century--before the buildup in greenhouse gases began in earnest. The phenomenon is not uniform; some glaciers are expanding. Glaciation seems more closely related to regional precipitation patterns than to global temperatures. Likewise, the recent reports on Arctic temperatures and the polar ice caps display disturbing biases and selective use of data. The Arctic is warmer today than it was 30 years ago, but according to some records it is colder today than it was 70 years ago. If the recent studies had used 1930 instead of 1970 (an especially cold period) as the starting baseline, there would be no warming trend found. But also no headlines. So yes, there has been some melting of ice near both poles, but other evidence shows places where the ice is thickening. Most of the claims of sea-level rise are heavily disputed, too.
Before Spending Trillions. . .
In other words, we still don't know very much about many things that the media report as fact. The basic problem is that for all the heavy investment in climate research, climate science is still in its infancy, roughly in the same spot that genetics was in in 1950, when it was decades away from mapping the human genome. The basic theory of global warming is right, but there are huge gaps in our knowledge and we're a long way away from an understanding of climate adequate to base trillion-dollar economic decisions on.
Don't expect much progress from the international effort to get to the bottom of the issue: the U.N.'s Intergovernmental Panel on Climate Change (IPCC), which is busy generating its fourth assessment report ("4th AR" in the jargon), due in 2007. The 4th AR aims to represent the latest "scientific consensus" about the sum total of the world's ongoing climate research -- an immense project.
The problem with the IPCC process, however, is that the scientists and experts participating in each iteration have become increasingly biased toward climate alarmism. It is getting harder to separate the ideologically motivated alarmists from the honestly worried scientists. Past assessment reports, especially the 2nd AR in 1995, were badly politicized by U.N. bureaucrats, misrepresenting what the report actually contained. Skeptics qualified to participate have found the IPCC process too frustrating and have dropped out; for example, Richard Lindzen, a participant and chapter author in the 3rd AR, is not participating in this round. More and more, the IPCC is becoming an echo chamber for just one point of view, and is closing itself to outside criticism. Its members, in the fashion of environmental activists, have taken to demonizing their reasonable critics.
The case of David Henderson and Ian Castles is a good example. Henderson, the former chief economist of the Organization for Economic Co-operation and Development, and Castles, the former head of the Australian Statistical Bureau, noticed two years ago a serious methodological anomaly in the IPCC's 100-year greenhouse-gas emission forecasts that are the primary input to computer climate models. Henderson and Castles made a compelling argument that the forecasts were unrealistically high. Everyone recalls the first day of computer-science class: garbage in, garbage out. If future greenhouse-gas emissions are badly overestimated, then even a perfect computer model will spit out a false temperature prediction. Since Henderson and Castles's initial critique, the IPCC's forecasts have been subject to withering criticisms from dozens of other reputable economists, including a number of climate alarmists who, to their credit, argue that this crucial question should be gotten right.
The IPCC's reaction to Henderson and Castles was startling: It issued a vituperative press release blasting them for peddling "disinformation." Some scientists and economists connected with the IPCC have said publicly that the press release was a regrettable error. But it is typical of the increasingly arrogant IPCC leadership. The IPCC's chairman, Dr. Rajendra Pachauri, recently compared eco-skeptic Bj rn Lomborg to Hitler. "What is the difference between Lomborg's view of humanity and Hitler's?" Pachauri told a Danish newspaper. "If you were to accept Lomborg's way of thinking, then maybe what Hitler did was the right thing." It is hard to have much confidence in an organization whose chairman can say this and keep his job. Moreover, despite the cascade of criticism of the IPCC's emissions forecasts, the 4th AR is going to use the same set of emissions forecasts for its next round of climate models, thereby assuring a garbagey result. The IPCC says it would take too long to do a fresh set of forecasts. Pachauri waves off all criticism, saying the science is "settled." Richard Lindzen notes that the "consensus science" of eugenics was equally "settled" 100 years ago. The greens accuse climate skeptics of denying reality, but it is the greens who have their heads stuck in a dark place.
Steven F. Hayward is resident scholar at AEI and the author of the annual Index of Leading Environmental Indicators.