Disaster scenario for the 21st century? No, historical footnote. This happened 50 years ago.
There was a global-warming scare in the 1930s. Then, as now, temperatures rose for several years running. Then, as now, scientists speculated that artificial carbon dioxide was the culprit; that the future could only be hotter.
Immediately it got cold. From 1940 through the 1970s global temperatures declined, hitting bottom during the frigid winter of 1976-77. Environmentalists declaimed that an ice age was beginning.
Immediately it got hot. Through the 1980s one warm year followed another. Some of the same voices that had cried ice age began to proclaim global warming, and this time the idea stuck. In Rio, the world’s leaders will sign a treaty which formally certifies the notion that a dangerous global warming is in progress.
The Rio treaty is an important step, though for reasons tangential to the current warming scare. For much as the greenhouse effect exists in the popular imagination, there is little evidence it has manifested in “the laboratory of nature.” Consider:
“The year 1990 was, of course, just the latest ‘warmest year on record’,” says Sen. Al Gore (Democrat of Tennessee) in his book “Earth in the Balance,” which calls the greenhouse effect “the most serious threat that we have ever faced.”
Hot compared to what? The “record” greenhouse proponents cite goes back only to 1880, when systematic preservation of weather data began. It turns out that 1880 was a cold year. Earth could experience “record” warmth and still remain cool compared with most of its past. Even after the 1980s warming, global temperatures still run 2 to 4 degrees Fahrenheit lower than through most of the period of civilization.
Starting around 1500, temperatures declined in an event called the Little Ice Age. For three centuries winters were harsh and harvests uncertain; the canals of Holland froze. Around 1850 temperatures began to rise again. Thus when dawned this century of industrial sprawl, the climate was already warming on its own.
About 1950, emissions of greenhouse gases took off. The warming rate, which should have escalated, promptly slowed. Pat Michaels, a climatologist at the University of Virginia, says, “Every annual high since 1950 falls below the trend of the natural increase” happening anyway when the big emissions began.
A net advance of about one third of 1 degree is what made the 1980s the hottest decade “on record.” Some researchers believe that amount is within the standard deviation, or natural variability, of the weather. In other words the warm 1980s might be an omen. Or mean nothing whatsoever.
Despite these conflicting signals, global warming is not an incomprehensible realm. Sense can be made of the subject by examining its three components: greenhouse science, greenhouse economics and greenhouse politics.
Global warming has already arrived, in disastrous ways, in the foothills of the Rocky Mountains. At the National Center for Atmospheric Research (NCAR) in idyllic Boulder, Colo., the greenhouse effect has struck hundreds of times.
The center operates one of the world’s leading General Circulation Models (GCMs), computers that simulate the human trespass on the atmosphere. When technicians run the GCM, they get bad news. Computers predict that a doubling of atmospheric carbon dioxide–likely for the next century, without advances in energy efficiency-will warm the earth from 3 to 9 degrees. The long end of the prediction would be calamitous. Most scientists who work with GCMs are greenhouse true believers.
When news reports say there is a scientific consensus that the earth will warm, what they mean is there is agreement that computers predict a warming. This is different from saying that experts believe global warming will happen. On the question of what will happen, the only scientific consensus is that the sky will remain blue.
The most important documents in the greenhouse debate, a series of statements from the U.N.-affiliated Intergovernmental Panel on Climate Change, rely on computer models. IPCC reports were the centerpiece of negotiations on the Rio climate treaty. Within the technical sections can be found many arguments against a greenhouse emergency. But the IPCC “policymaker’s summary,” the only section political leaders ever glance at, concentrates on the gloomy predictions of the GMCs. So what are the chances the models are right?
The most basic distinction in greenhouse science is between weather and climate. Weather is what happens today; climate is what happens over the next century. Last winter was the warmest in a century in North America. It also snowed in Israel. These facts reveal nothing other than that the weather is changeable, something known to Ben Franklin.
Most weather variations are essentially meaningless minor oscillations of a vast, complex system whose basic parameters are still only crudely understood. Weather-forecasting computers cannot project what the temperature will be next week; imagine trying to predict temperatures for the next century.
Because the biosphere is vast and complex, even advanced computers can deal with it only in approximations. When the climate model at NCAR prints out an image of the globe, Japan and the United Kingdom are absent. These nations are too small to fit under the model’s “resolution limit.”
Another problem is that even the best temperature records are fuzzy by a few shades of a degree, plus or minus. That is a tenuous basis on which to analyze a greenhouse effect which so far is, at worst, only slightly larger than the margin of error in the numbers. Stephen Schneider of NCAR acknowledges, “It’s possible that everything in the last 30 years of temperature records is no more than noise.” Noise is statistician’s slang for little numerical fluctuations that don’t add up to a hill of beans.
Because of such limitations, when global climate models are run in reverse, they fail to “predict” the present. Researchers who have set GCMs to the conditions of 1880 find the models say global temperatures should by now have risen as much as 5 degrees. But the actual increase over the last century is at most 1 degree.
Climate modelers know about such problems, and “tune” their computers to compensate. James Hansen, director of a NASA-affiliated GCM project, reports that his model is sufficiently tuned that, run in reverse, it now predicts only twice as much warming as has actually been observed. This may still sound worthless; in fact it’s a significant step toward a climate model that can be trusted.
Hansen put his reputation on the line by doing something modelers dread– making a testable prediction. His computer thinks global temperatures will decline about 1 degree during 1992, because the eruption of Mount Pinatubo pumped enough pollutants into the air to interfere with sunlight reaching earth. When last winter was warm, modelers braced for embarrassment; but a late spring followed, so the prediction may rally. The bottom line on 1992 will help determine whether GCMs can align with reality.
Computer models must contain assumptions about how earth’s climate operates. But the level of all ecological knowledge is primitive, and climate is no exception.
Till recently researchers assumed that water in the air behaves the same whether it is suspended as vapor or ice crystals. Then experiments showed there is a big difference between the two states. When the British Meteorological Office adjusted its GCM to take this into account, the predicted greenhouse bad news declined from about 10 degrees to about 3.
Most scientists assumed that sulfur dioxide, which causes acid rain, is also a greenhouse gas. But new research shows it is actually a coolant. Sulfur forms what might be called a smog mirror, increasing the sunlight reflected back into space.
As recently as last summer the chemicals that deplete the ozone layer, CFCs, were considered potent global-warming agents. Scientists were “certain” of this. Then researchers discovered that CFCs cool the air just as much as they warm it.
Science traditionally thought the energy output of the sun-the driving force of climate-absolutely invariant. Satellite measurements begun about a decade ago show this is not the case. The sun’s production varies slightly from year to year, according to Judith Lean, an astronomer at the Naval Research Laboratory.
Shortly after George Bush took office two credentialed scientists, Robert Jastrow and William Nierenberg, began to argue that the newly discovered solar variations explain recent temperature trends. They had considerable influence on the White House, particularly on former chief of staff John Sununu, a greenhouse agnostic. Hansen of NASA then demonstrated that a temporary cooling greater than has been observed in our sun or any similar star may be necessary to counter the temperature increases which GCMs predict. Besides, what if the sun’s output goes up? That little complication caused solar variation to fall out of favor with the White House as a global-warming counterbalance.
Still other questions concern the seas and glaciers. Oceanographers long assumed that ocean currents are relatively stable. But developments like the persistent El Nino fluctuations now suggest that sudden shifts in the circulation of ocean water may be gremlins in climate malfunctions. Scott Lehman of the Woods Hole Oceanographic Institution recently published evidence that past shifts in ocean currents have caused sea surface temperatures to plummet 11 degrees in 40 years, an unheard-of rate.
It is an article of faith in the greenhouse community that natural temperature movements are extremely gradual. Rapid movements must be artificial and therefore pernicious because they will confront the biosphere with unnatural pressure. If it turns out, instead, that rapid temperature swings do occur naturally, all greenhouse arguments may go back to the drawing board.
Greenhouse theory posits that a warmer world would hold dire elevations of sea levels, as glaciers melt and return their water to the oceans. A decade ago, 10-foot increases were commonly projected for the 21st century; this amount would swamp coastal cities and several island nations. Now the estimates are down to one to seven feet. The highest claimed actual number for sea-level increase during the last 100 years is 11 inches, and most researchers think the real figure is much smaller.
Why isn’t the sea rising* Because many glaciers are growing, not melting. Researchers have identified places where ice is in retreat: most are tropical or relatively small glaciers that may have been melting since the end of the Little Ice Age. In the arctic and antarctic locations where the major ice masses reside, net glaciation may be increasing. A researcher named Jay Zwally surprised the climate business two years ago by showing that the central glaciers of Greenland have grown in the very years that global temperatures got higher.
Glaciers get bigger while temperatures get higher: impossible? No, perhaps inevitable. In the zones that adjoin the North and South poles it’s so cold that snow, the raw material of glaciers, rarely falls. Increasing temperatures might cause more precipitation, but not enough additional melting to counter the buildup. This could mean more of the world’s water locked up in ice.
For his part Schneider believes there is a more straightforward explanation for the expanding Greenland glacier-that it’s simply gotten colder in Greenland. Indeed, some data suggest that it has.
It’s colder in Greenland? Isn’t the earth supposed to be warming.? Climate shifts are not uniform. There’s nothing strange, except to our sensibilities, about a mild winter in Minneapolis while a blizzard shuts down Jerusalem. But this seems a strike against greenhouse theory, which holds that warming would center in the high latitudes of the Northern Hemisphere. Researchers generally concur that warming has favored the Southern Hemisphere.
Recently Thomas Karl of the National Climatic Data Center demonstrated that summer and daytime highs have changed little during recent decades. But winters have indeed been mild, and nighttime lows have been less low.
This esoteric finding contained something to offend everybody in the climate debate. Greenhouse theory suggests that warming should peak on summer afternoons: the worst time, because daytime highs kill crops and push up energy demand. Karl’s work suggests nature is doing the opposite.
But the study may also lend greenhouse theory new impetus. Perhaps the gases that humans put into the atmosphere are warming the earth, but that effect is “masked.” During the day, carbon dioxide may trap heat while the smog mirror of sulfur pollution reflects sunlight, netting no change. At night the heat trapping continues but the reflections stop; temperatures edge upward. Perhaps greenhouse theory should be adjusted to predict warming at night, exactly what Karl has found.
Underlying all climate uncertainties is an ultimate question: does the greenhouse concept make sense?
There’s the matter of the missing carbon. Human mischief puts 7 billion tons of carbon into the air annually. Yet atmospheric monitors detect only half that amount. Where does the rest go? One possibility: though deforestation is proceeding in some places, forestation is happening in others. Between the fast-growth “managed forests” for timber and the expansion of forest acres in many developed countries, there may be an unprecedented number of young trees on earth inhaling extra carbon.
And there’s the little mystery of the “feedbacks.” Over the long term, earth’s climate is remarkably self-regulating. How? Maybe if the climate warms, the air becomes more moist, which causes more clouds, which bounces more sunlight back to space. If the climate cools, the air becomes dry, reducing cloud cover and allowing more solar energy in. Natural feedbacks may work in this benevolent fashion. Or they may backfire. Michael Oppenheimer of the Environmental Defense Fund suggests warming will create a diabolical feedback in which plant decay accelerates the addition of natural carbon to the atmosphere, pushing the system over the brink.
The inability of the science community to agree on issues as basic as whether feedbacks will be negative or positive makes Richard Lindzen, a climatologist at MIT, suspect there is a fundamental flaw in the global-warming concept. Lindzen calculates that in nature, CO2 exhibits only about one quarter of the power it seems to possess under lab conditions. Why?
Greenhouse theory presumes that warmth vents away from earth’s surface mainly as radiant heat-the wavy lines rising from a parking lot. The notion “is simply untrue,” Lindzen says.
Most warmth, he believes, rises through convection in blocks of air. While radiant heat encountering greenhouse gases may be trapped, convective currents blocked in one place will move elsewhere, blown on the wind, till they find an “open vent” that allows them to release energy upward, above the greenhouse barriers.
Lindzen’s idea has an appealing ability to answer some puzzles about greenhouse theory; it also has drawbacks. Neither Lindzen nor anybody else can yet say exactly why the climate is what it is. That is an argument against greenhouse panic, but not for inaction. A principle of wisdom holds: we don’t know what we don’t know. Until such time as humanity really knows what makes climate tick, we would be fools to take unnecessary risks. And as the economics of the greenhouse show, insurance is affordable.
Here’s an aspect of the controversy that drives environmentalists to distraction: is global warming bad? The high range of predictions for a warmer earth would be awful. But mild warming is in society’s interest, particularly its economic interest.
No one contends that the mild warming so far has done harm. Warmth, after all, is essential to life; as the tropical forests show, nature adores warmth. Cities like London and New York may be less likely to have a white Christmas, which is sad for sentimental reasons. (One reason mild winters spook many Americans is that the baby boom was born into the 1950s and 1960s, a period of unusual cold and snow. Recent winters don’t conform to childhood memories.) But the prime results of warming are pluses.
Here’s the bottom line on the 1980s, the “hottest years on record”: food production was strong. Energy consumption was soft, winter peak demand being a key variable in power needs. In turn, energy prices declined. In real terms gasoline now costs less than during the 1950s, a period enshrined in our collective nostalgia as Energy Heaven. “I have a hard time following why longer growing seasons, lower energy prices and fewer subzero days in North Dakota are the new apocalypse,” says Michaels.
If it were certain that current temperature trends were natural, we might now be reading stories about the wonderful global warming. But the idea that clumsy human tinkering with the atmosphere may inadvertently have done something useful-that we benefit from pollution!-is almost too peculiar for polite discourse. In a sense, humanity flatters itself by believing it has acquired the power to disrupt nature on a global scale. We like to view ourselves as so mighty the very planet quakes before our inventions. It’s almost annoying to hear that with all our imposing power stations and gleaming cars and soaring aircraft, artificial-carbon emissions are only 4 percent of the natural level.
Warming, of course, may not stay mild: the best reason for greenhouse controls. During the early Bush administration, estimates batted around for greenhouse reductions ran from $100 billion to a mind-bending $3.6 trillion. Such calculations contained an astonishing omission. The way to control carbon emission is to make energy use more efficient. The big numbers took into account the capital costs of new conservation technology, but not the value of the fuel saved.
Factor in the energy savings, the analysts Amory and Hunter Lovins showed in a landmark 1991 study, and the cost of global-warming control not only falls-it becomes possible to imagine cutting greenhouse gases at a profit. Even the National Academy of Sciences, often grumpy about environmental reforms, says that the first 25 percent of greenhouse pollutants could be controlled at a price equivalent to just 11 cents per gallon of gasoline.
Savings from greenhouse controls would not be confined to the specific fossil-fuel reductions at any factory, office or automobile that became more efficient. They would spread broadly to all energy prices, by reducing demand.
The central reason world energy prices remain low is that fuel use has become more efficient. The U.S. economy now requires 28 percent less energy per dollar of output than two decades ago. Somehow the economic payoff goes unappreciated. Everyone is keenly aware from the 1974 and 1979 energy crunches that fuel pricing responds faithfully to changes in supply. Constantly overlooked is that fuel prices also follow the second half of the supply-and-demand equation, responding faithfully to demand. When demand for energy moderates, prices go down.
After Iraq invaded Kuwait, oil prices spiked on the expectation that supply would be disrupted or demand would rise through panic buying. Neither happened; prices rapidly fell. There was extensive public reaction to the increase and hardly any notice of the decline, though the latter was far more significant. No panic buying occurred because, through efficiency gains, society was less obsessed about oil supplies than the last time around. Cheap energy used efficiently is a best-of-both-worlds situation for everyone except a few desert princes.
Currently the White House is pushing its National Energy Strategy. It contains worthwhile provisions, yet lacks an important insight: that resource conservation, pollution control, lower energy prices and a hedge against global warming might be achieved simultaneously by a comprehensive commitment to improved fuel efficiency. A new program to pursue all these objectives at once would seem one of those rare public-policy areas where the light at the end of the tunnel is bright and beckoning. Through the last decade greenhouse emissions have either been flat or declined slightly, from the effects of conservation pursued with little encouragement from Washington. Greater gains might be had with modest incentives.
Finally, inexorably, there are the efficiency requirements obliged by population growth. Consider an example offered by William Lee, CEO of Duke Power, a North Carolina utility. Suppose that the world population stabilizes at the low end of the United Nations estimate: 5.4 billion souls today, it expands to 9 billion. Next, suppose that a majority of the world’s residents reach a standard of living equal to one half that enjoyed by Americans. Finally suppose that all energy uses, from factories to sports cars, grow twice as efficient. Under these optimistic assumptions, the world will need to generate three times as much power.
Seen in that light, significant improvements in energy efficiency are imperative whether the thermometer is going up, down or sideways.
For two years, negotiations have progressed at the highest levels of government over the climate treaty to be signed in Rio. There has been personal lobbying between heads of state, Helmut Kohl taking a full hour with George Bush to urge that the United States embrace the treaty. The European Commission staked its nascent prestige on its ability to make the treaty happen. The Japanese, normally circumspect about diplomacy, trumpet themselves as greener-than-thou on the subject.
The proposed treaty has inspired wild verbiage. It’s anything from a last-ditch attempt to save a dying planet to a cynical plot to impose a socialist industrial order in the guise of climate protection. Global warming can engender such polar positions because the actuality of the subject is so pleasingly nebulous. Crime, welfare, health care: most issues are anchored in the muck of the real. The greenhouse effect is a blank slate onto which par may project whatever they wish to behold.
Now Bush will go to Rio. The treaty he will sign obligates nations to cut greenhouse emissions, but, at Bush’s insistence, does not specify by how much or when cuts must occur. Some have declared the compromise a hollow outrage. It’s not.
First, any action on pollution control should always be welcomed. Second getting on paper the need for global energy efficiency is a vital step. Progress may be agonizing, but most nations usually do respond to treaty commitments: pressure for new energy-conservation initiatives will grow.
Third, the Rio climate agreement will slip into international law the premise that nations must consider global environmental consequences when making internal economic decisions. This is a powerful, progressive concept whose codification will pay important environmental dividends in years to come.
But before you start to feel good …
This March the World Health Organization published a thick volume on global environmental damage. The book contains paragraphs here and there about issues that concern the affluent in the industrial North: the greenhouse effect, trace pesticide residues, skin cancer from sunbathing. And it goes on for hundreds of pages about the environmental issues that matter to the majority of the world’s population, such as 3.2 million children dead last year from diarrheal disease. Most of the deaths could have been avoided by safe drinking water and decent sanitation.
Three million children dead, versus maybe, someday, another degree Fahrenheit. On the run up to Rio, the world’s attention has focused on the hypothetical threat of global warming, to the exclusion of environmental menaces that are palpable and awful right now-but which only affect the abstract legions of the brown, distant poor.
Among Third World intellectuals there is growing suspicion that developed countries suddenly care about the greenhouse effect for selfish reasons. Global warming might affect property values on Cape Hatteras; unsafe water in Bangladesh will not. Energy efficiency, supposedly a terrible sacrifice for the industries of wealthy nations, will improve their competitiveness in the emerging global economy.
And the capital required for greenhouse controls? The North will invest this on itself, rather than sharing resources with the South for, say, sewage abatement. Hasn’t anybody wondered why a delegation of corporate CEOs met with Bush to ask him to back the climate treaty? Because they’ve realized greenhouse control is in their own self-interest.
Ultimately all environmental protection is in everybody’s self-interest. The dawning of this consciousness, once complete, will drive great reforms yet to come. Till that day, the First World can recover some of its moral perspective on global warming by recognizing a link between greenhouse emissions and international aid.
Right now the developed nations are the big greenhouse offenders. But early in the next century the Third World will pass the First for this dubious distinction.
Once the next level of energy-efficiency improvements are accomplished in the North, affluent nations will approach the point of diminishing returns, after which huge investments are required for small conservation gains. The rest of the world will, however, be burdened for decades to come by inefficient energy systems: ones where relatively small amounts of capital can create large benefits both for the Third World poor and for the global biosphere. Where should that money come from? Us.
