Global Warming: How to Think Sensibly

The crusade to fight global warming with tough reductions in greenhouse-gas emissions has entered its war-room phase. Already we are seeing the fruits of a multi-million dollar PR campaign: lavish cover stories in Time magazine ("Be Worried, Be Very Worried"), Vanity Fair, and Newsweek; multiple global-warming scare specials on PBS, HBO, and the network news; and, finally, the imminent release of Al Gore's explosive and exceedingly popular documentary An Inconvenient Truth.

Soon the Ad Council will begin airing TV spots pulling on the usual heartstrings: We have to stop global warming for the children! One of these ads--featuring a montage of kids counting down "tick, tick, tick"--is reminiscent of the infamous 1964 anti-Goldwater ad.

Underlying this effort is a sense of panic over two things: the collapse of the Kyoto Protocol, and frequent polls showing that Americans aren't buying into global-warming alarmism. The latest Gallup poll on environmental issues found that only 36 percent of Americans say they "worry a great deal about global warming"--a number that has hardly budged in years.

Global warming, Gallup's environmental-opinion analyst Riley Dunlap wrote, puts people to sleep. Even among those who tell pollsters that the environment is their main public-policy concern (who are usually less than 5 percent of all Americans), global warming ranks lower than air and water quality, toxic waste, and land conservation.

There is no conspiracy behind the global-warming-awareness campaign; in fact, the environment lobby is quite open about what it's up to. The Yale School of Forestry and Environmental Studies recently published a plan to elevate climate change to the top tier of the political agenda.

This report, Americans and Climate Change, grew out of a summit meeting of environmental leaders held last year in--naturally--Aspen. It lists 39 recommendations for raising the percentage of the public that is alarmed by global warming from the anemic mid-30s to over 50 percent. Tactics include everything from manipulating public-school curricula to reaching out to NASCAR's fan base to seizing events like Hurricane Katrina as "teachable moments."

The Yale report also does us the favor of making its authors' desire to politicize climate change explicit. One faction of environmentalists openly argues that "the only way to proceed is to exercise raw political power, wake up the public about the urgent nature of the issue, create a major public demand for action comparable to that which stimulated major environmental legislation in the 1970s, pursue outright victory at the polls." In other words, we need to boot out those evil Republicans.

GAME OVER, THEY SAY

This campaign intimidates the public and would-be dissenters with its unrelenting line that the science of global warming is settled, full stop. (Time swallowed it whole: "The debate is over. Global warming is upon us--with a vengeance. From floods to fires, droughts to storms, the climate is crashing.") The "consensus" that human activities are playing a role in the earth's so-far mild warming trend is misrepresented as agreement that we are headed toward catastrophic results that can be prevented only by immediate and drastic action.

In fact, many scientists don't believe the catastrophe scenarios. But those who dissent from the politicization of climate science face withering ad hominem attacks. For example, the National Environmental Trust and Vanity Fair attacked Frederick Seitz, the 94-year-old former president of the National Academy of Sciences, for supposedly taking money from R. J. Reynolds while he was president of Rockefeller University to deny the health effects of smoking. In fact, the money went into a medical-research project unrelated to tobacco that led to a Nobel Prize in medicine. The climate-action caucus clearly feels no shame about employing smear tactics. One might even go so far as to accuse it of scientific McCarthyism.

But try as it might, this caucus cannot change two facts that have been evident since climate change first came to the fore in the late 1980s. First, even though the leading scientific journals are thoroughly imbued with environmental correctness and reject out of hand many articles that don't conform to the party line, a study that confounds the conventional wisdom is published almost every week. Sometimes these studies even find their way into Science and Nature. Most recently, the April 20 issue of Nature carried a study that casts serious doubt on the high-temperature forecasts of computer climate models.

And last fall, Science published a study finding that the Greenland ice sheet, whose perimeter melting is presented as a sign of imminent sea-level rise (never mind that the Vikings observed similar melting 1,000 years ago), is gaining ice mass in the interior. (The oddest aspect of the Greenland story is that average temperatures in southern Greenland appear to have fallen during the 20th century; ice-mass changes probably have more to do with regular variation in Atlantic ocean currents--a natural phenomenon known as Atlantic Multidecadal Oscillation.) The media tend to ignore such research while giving disproportionate coverage to the latest news about melting glaciers or expiring frogs.

Climate alarm is likely to get a fresh infusion of "authoritative" science next year when the Intergovernmental Panel on Climate Change (IPCC) issues its Fourth Assessment Report (AR4). Early indications are that AR4 will remove its upper-bound estimate of potential warming at the end of this century (currently 5.8 degrees Celsius), assuring a fresh round of media headlines that the situation is worse than we thought. Yet the computer climate models remain plagued with weaknesses and biases--from the doubtful emissions forecasts that go into the front end, to assumptions about the linearity of the relationship between greenhouse gases and temperature that affect the results.

As MIT climatologist Richard Lindzen argues, the computer models overestimate the sensitivity of climate to greenhouse gases and don't adequately account for "negative forcings" (the technical term for natural processes that mitigate potential temperature increases). It is likely, in Lindzen's judgment, that we have already reached the threshold of diminishing "positive forcings" (that is, increases in temperature) from additional greenhouse-gas emissions.

Most of the computer models predict temperature increases of two to three degrees Celsius by the year 2100, which, while not an "end of civilization as we know it" catastrophe, could cause significant problems for the planet. Even discounting for the biases in the models, these predictions still raise questions about what precautions are appropriate to take against a low-probability event with potentially serious consequences. This leads to the second difficulty for the climate-change crusade: There are alternatives to its insistence that the only appropriate policy response is steep and immediate emissions reductions (on the order of 60 percent).

Kyoto's 8 percent reduction target is modest by comparison, but no nation is honestly meeting it. (Britain met its 2000 target as an unintended consequence of Margaret Thatcher's decision 20 years ago to smash the coal miners' union and move the nation to natural gas. But even with this wind in its sails, Britain is seeing its greenhouse-gas emissions start to rise again.) The energy technologies to achieve a 60 percent reduction in emissions while meeting the world's energy needs simply do not exist.

Environmentalists were against fossil fuels long before climate change rose to prominence, and this monomania is evident in their continued opposition to nuclear power, the only technology that can generate large amounts of energy without emitting greenhouse gases. (In a recent C-SPAN appearance with me, the legislative director of the League of Conservation Voters said that nuclear power had no role to play in mitigating climate change.) Instead, environmentalists advocate a supposedly market-friendly "cap and trade" program. Such a program would impose downwardly ratcheting emissions caps; but instead of creating thousands of detailed Clean Air Act-style regulations, it would grant "emissions permits" to companies, which would be able to trade these permits among each other. If one company's emissions were lower than the allowed amount, it could trade or sell its "leftover" allotment to a second company, which could add that amount to its own emissions allotment. The idea of such trading is to let the market guide emissions reductions to the companies able to undertake them most efficiently.

"Cap and trade" is thought to have been a great success in reducing sulfur-dioxide emissions at low cost. But there is a world of difference between sulfur dioxide and greenhouse gases. For a variety of reasons, curbs on sulfur dioxide did not impose any constraint on net energy production, whereas a greenhouse-gas-emissions cap ultimately would constrain energy production.

A COMMONSENSE AND WORKABLE PLAN

A sensible climate policy would emphasize building resilience into our capacity to adapt to climate changes--whether cooling or warming; whether wholly natural, wholly man-made, or somewhere in between. A resilience policy, instead of focusing solely on emissions controls, would have four parts.

First, the transition to a post-carbon world decades from now will come about more quickly and efficiently by keeping energy markets open and unregulated than by subsidizing particular energy technologies or artificially making energy more expensive for producers and consumers. Efforts to subsidize energy paths will inevitably fall prey to interest-group lobbying (as witness the domestic ethanol lobby's success in winning tariffs on foreign ethanol), and will likely delay the development of promising technologies.

Second, we should implement practical carbon-sequestration measures: the capturing and storing of carbon in any number of places, whether underground, deep in the ocean, or in biomass (think more trees). There is much sequestration research under way, but many environmentalists oppose it because it would let us off the hook for our original sin of energy consumption.

Third, we should consider strategies of adaptation to a changing climate. A rise in the sea level need not be the end of the world, as the Dutch have taught us. Developing countries with vulnerable coastlines will be better able to adapt if their economic growth is not constrained by severe energy limits. And here at home, the federal government ought to stop subsidizing flood insurance and coastal development anyway; potential climate change is another reason to eschew such policies.

Finally, we should consider climate modification. If humanity is powerful enough to disrupt the climate negatively, we might also be able to change it for the better. On a theoretical level, doing so is relatively simple: We need to reduce the earth's absorption of solar radiation. A few scientists have suggested we could accomplish this by using orbiting mirrors to rebalance the amounts of solar radiation different parts of the earth receive. Right now this idea sounds as fanciful as Ronald Reagan's Strategic Defense Initiative seemed in 1983, but look what that led to. New York University physicist Martin Hoffert points out that the interval between the Wright brothers' first flight at Kitty Hawk and Neil Armstrong's first step on the moon was a mere 66 years. It is entirely reasonable to expect vast changes in our technical capacity before the century is out.

In the end, a relentless campaign to extend political control over the world's energy use is likely to fail, in part because, even if severe climate change is in our future, most people intuitively recognize that rhetoric about "the end of civilization as we know it" is inconsistent with human experience. Our distant ancestors survived an ice age with little more than animal skins, crude tools, and open fire pits. For all the talk of science and progress, the global-warming alarmists betray an astonishing lack of confidence in human creativity and resiliency. It's almost as if the scientific community had abandoned the idea of evolution.

It has been four years since President Bush declared the Kyoto Protocol a dead letter, but the campaign to impose industrial greenhouse-gas emission controls on the American economy shows no signs of letting up. Although Sen. John McCain's bid last month to include concrete emission controls in the pending energy bill attracted only 38 votes, the Senate subsequently passed a resolution calling on Congress to "enact a comprehensive and effective national program of mandatory, market-based limits on emissions of greenhouse gases that slow, stop and reverse the growth of such emissions." An attempt to table the resolution was opposed by Republican senators Lamar Alexander, Lincoln Chafee, Susan Collins, Mike DeWine, Pete Domenici, Lindsey Graham, Judd Gregg, Richard Lugar, John McCain, Olympia Snowe, Arlen Specter, and John Warner. Apparently, even red-state Republicans are having doubts about Bush's position on climate change.

One might think that the increased political buzz around global warming is driven by science. One would be wrong. The scientific case for alarm is no more compelling today than it was yesterday.

The first (and sometimes last) stop in the global-warming debate is the question, Is it real? The answer seems to be yes. Ground-based and oceanic temperature records show warming of about three-quarters of a degree Celsius in the last century. About half of that warming, however, occurred before World War II and is widely thought to be related to solar activity. Satellite and weather-balloon records, which do not go back as far, show less warming in the late 20th century than the land-based stations.

What's causing this warming? We don't know. As the vice president of the U.N.'s Intergovernmental Panel on Climate Change (IPCC), Yury Izrael, wrote bluntly last month, "There is no proven link between human activity and global warming." Given the extreme variability of global temperature, warming might simply be statistical noise. It might result from solar and/or volcanic activity. It might be caused by industrial emissions. And it might come from some combination of the three.

What do most scientists suspect is going on? The best way to ascertain the "scientific consensus" is to look at the latest report of the IPCC (released in 2001), which purports to summarize the state of scientific knowledge on global warming. Here's what it says: "Most of the observed warming over the last 50 years is likely to have been due to the increase in greenhouse gas concentrations." The report finds that it is "unlikely (bordering on very unlikely) to be entirely the result of internal variability," and that "natural forcing alone [i.e., solar and/or volcanic activity] is unlikely to explain the increased rate of global warming since the middle of the 20th century."

The promiscuous use of such vague terms as "likely" and "unlikely" by scientists who are trained in precision speaks volumes about how much is unknown. At the very least, such language makes it impossible to accept the Greens' claim that "the debate is over," particularly given all the uncertainty--fully discussed in the IPCC report--regarding long-term climate records and important data on atmospheric feedbacks. In fact, uncertainty about future climate conditions is greater in the 2001 IPCC report than it was in the 1995 IPCC report.

Do other reviews of the scientific literature tell a different story? It depends on whom you ask. An article by Naomi Oreskes in Science last December examined 1,000 scientific papers published since the early 1990s. Oreskes concluded that 75 percent of those papers either directly or implicitly supported the argument that industrial emissions are driving global warming, and none directly argued to the contrary. Asubsequent review of the same articles by Benny Peiser, a senior lecturer on the science faculty at Liverpool John Moores University, found nothing of the kind. Peiser concluded that only one-third of the papers reviewed by Oreskes actually supported the "consensus view," and only 1 percent did so explicitly.

In any case, debating what constitutes the mainstream thinking on climate change is not particularly enlightening. Regardless of how one defines "the consensus," scientific truth is not revealed by a show of hands. As Thomas Jurbin demonstrated in The Structure of Scientific Research, the history of scientific progress is a history of once-solid consensuses being overthrown by minority skeptics. In short, today's consensus proves nothing.

Even more heated than the debate about the cause of climate change is the debate about its likely effects. In fact, most of the so-called skeptics who publish in peer-reviewed literature accept the contention that mankind is probably responsible for most present-day warming. They argue, however, that the warming has been and will continue to be quite modest, and that the pattern of warming we're seeing does not suggest that a parade of horribles awaits us.

The skeptics are on solid ground here because the atmosphere simply has not proven to be as sensitive to industrial greenhouse-gas emissions as some theorists have feared. Unless some temporary phenomenon is masking the effect of such emissions, atmospheric physics suggests that warming will occur at a linear rate--a conclusion affirmed by almost all the computer climate models in existence. This insight suggests a simple exercise: Plot temperature data over the last 50 years and draw a trend line to see what the future has in store. Doing so suggests that warming will likely be at the low end of the IPCC's projections--about 1.5 degrees Celsius by the year 2100.

Should we worry about such modest warming? From an ecological perspective, probably not. Because water vapor is responsible for 94 percent of the natural greenhouse effect, industrial greenhouse gases have a greater impact in dry air masses than in wet ones. Fully 78 percent of the warming has been concentrated in the driest air masses, which are primarily found during the winter (when 69 percent of the warming has occurred), at night, and in the northern latitudes. However, much media have failed to report on this part of the story.

The fact that winter nighttime lows in the Northern Hemisphere aren't quite as cold as they used to be need not cause anyone to panic--and there seems not to be an increased incidence of the destructive weather events that would follow from warming in wet air masses. According to the IPCC, "[T]here is little sign of long-term changes in tropical storm intensity and frequency," and "no compelling evidence" that local severe-weather events are on the rise. Most important, "no significant acceleration in the rate of sea level rise during the 20th century has been detected." Precipitation in the northern hemisphere has likely increased by a meager 0.5-1 percent a decade, but "no comparable systematic changes in precipitation have been detected in broad latitudinal averages over the Southern Hemisphere."

There are good reasons to think that a warmer world might be a better world. Agronomists, for instance, are fairly convinced that heavier concentrations of carbon dioxide in the atmosphere, as well as the longer and somewhat wetter growing seasons that follow from the greenhouse warming pattern, have already increased crop yields and will continue to do so. Warmer weather also leads to declines in energy use, and probably fewer weather-related deaths.

Not surprisingly, economists who have examined the implications of the warming projections offered by the IPCC have had a hard time proving the existence of net negative effects. In fact, Yale forestry economist Robert Mendelsohn has demonstrated that nations north of the equator will probably benefit from global warming, and that warming will likely prove an economic wash for the world as a whole.

Both sides in the global-warming debate contend that "sound science" should dictate public policy. For the foreseeable future, though, it's unlikely that scientists will be able absolutely to prove or disprove the proposition that industrial greenhouse-gas emissions are ushering in a dangerous warming trend. Even if scientists could prove this, they have no particular expertise at choosing among competing policy responses. Nor are scientists' levels of risk aversion, or their choices about how to hedge against risk, necessarily superior to those of anyone else.

.fa_inline_results, .fa_inline_results.left {

clear: left;

margin-right: 20px;

margin-top: 10px;

width: 220px;
}

.fa_inline_results.right {

margin-left: 20px;

margin-right: 0;
}

.fa_inline_results h4 {

margin: 0;

font-size: 12px;

border-bottom: 1px dotted #c3d2dc;
}

.fa_inline_results ul {

list-style-type: disc;

list-style-position: inside;

color: #3769DD;

margin: 0 0 15px;

padding: 0;
}

.fa_inline_results ul li {

margin: 0;

padding: 0;
}

.fa_inline_results ul li.title {

color: #333;

list-style-type: none;

font-weight: bold;
}

.fa_inline_results ul li.articles {

color: #333;

list-style-type: none;
}