Those air-conditioners that keep things cool and comfortable inside are helping make the outside world even nastier.

When it's hot and humid out and the air-conditioner's not running, America suffers. Babies break out in rashes, couples bicker, computers go haywire. In much of the nation, an August power outage is viewed not as an inconvenience but as a public health emergency.

In the 50 years since air-conditioning hit the mass market, America has become so well-addicted that our dependence goes almost entirely unremarked. A/C is built into our economy and our culture. Stepping from a torrid parking lot into a 72-degree, air-conditioned lobby can provide a degree of instantaneous relief and physical pleasure experienced through few other legal means. But if the effect of air-conditioning on a hot human being can be compared to that of a pain-relieving drug, its economic impact is more like that of an anabolic steroid. And withdrawal, when it comes, will be painful.

We're as committed to air-conditioning as we are to cars and computer chips. And a device lucky enough to become indispensable can demand and get whatever it needs to keep running. For the air-conditioner, that's a lot.

The costly care and feeding of AC

Like a refrigerator, an air-conditioner works by piping a chemical refrigerant through cycles of compression and expansion. The refrigerant absorbs heat from cool interior air and releases it to the hot air of the great outdoors. In doing so, it's impeded by the Second Law of Thermodynamics, or Entropy Law, which says that temperatures tend to even out -- that heat naturally flows from a hot to a cold area. So an air-conditioner has to mechanically compress the gaseous refrigerant into much hotter liquid form and pump it through outdoor coils from which it can release the heat it has absorbed. To do that requires a lot of energy, usually from a power plant or a vehicle engine.

Almost one kilowatt-hour of electricity out of every five consumed in the United States in a full year goes to cooling buildings. Much of the nation's excess power-generating capacity, which sits idle until needed to satisfy quick spikes in demand, has had to be built because of air-conditioning.

The electricity used annually to air-condition America's homes, stores, offices, factories, schools, churches, libraries, domed stadiums, hospitals, warehouses, prisons and other buildings (not including what's used to cool manufacturing processes and military facilities) exceeds the entire electricity consumption of the world's second and fourth most populous nations -- India and Indonesia -- combined.

The refreshing air that comes out of an air-conditioning system has an evil twin: carbon-laden exhaust from the utilities that power it. Just about 50 percent of U.S. electricity is generated with coal; 21 percent with other fossil fuels, mostly natural gas; 20 percent with nuclear fission; less than 7 percent with hydroelectric dams; and about 2 percent with biomass, wind and solar methods combined. Coal is the worst carbon dioxide producer, but all of those methods generate greenhouse gases and other ecological hazards during construction and operation.

In January, the Environmental Protection Agency (EPA) raised energy-efficiency standards for newly manufactured home central air-conditioners by 30 percent. Central air units typically last 15 to 20 years, so the new regulation will have little effect in the near future. Even if all units were replaced overnight, it would mean less than a 5 percent reduction in the power that's used to air-condition buildings. That's because the new rules don't apply to window units or to nonresidential air-conditioning.

The average household in the southeastern United States consumes almost twice as much electricity as the average household in New England, but air-conditioning doesn't account for that entire disparity. Southerners use a lot more power for all appliances, whatever the season. Of course, northern households consume more fossil fuel for heat, but in the dead of winter, heating cannot be dispensed with.

There is scope to save energy in both heating and air-conditioning by improving insulation. Energy used in heating could also be cut by setting thermostats at cooler temperatures, but air-conditioning is more of an all-or-nothing proposition. At a certain point on the thermostat, a stuffy, frugally cooled house or office becomes intolerable; a hot breeze from outside can be far preferable.

Driving from a cool home to a bracing workplace to a chilly supermarket would be a severe shock to the system if done in a non-air-conditioned car, so you'll find such cars only on "vintage" lots. Government tests have shown that running an air-conditioner can decrease a car's fuel efficiency by 4 miles per gallon. Excess fuel consumption is lower on the highway, higher in the city and incalculable when the engine and AC are left running in a parked pickup truck to keep a Dachshund comfortable.

(The long-running debate over whether you'll use less gas on a long highway trip by keeping the windows open -- which increases the car's aerodynamic drag -- or rolling them up and turning on the AC -- which puts an extra load on the engine -- seems to have ended in a tie.)

About 5.5 percent of the gasoline burned annually by America's cars and light trucks -- 7 billion gallons -- goes to run air-conditioners. That's equivalent to the total oil consumption of Indonesia, a petroleum-rich country with a population size comparable to ours. Four states -- California, Arizona, Texas and Florida -- account for 35 percent of that extra fuel consumption.

In years to come, we may be cranking air-conditioners up as high as they'll go to provide some relief from human-fueled global warming. But that will only aggravate the crisis. Air-conditioning accelerates the greenhouse effect not only by increasing the use of coal and other fossil fuels but also by releasing refrigerants.

Since the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, there has been a major shift in types of refrigerants used in air-conditioning and refrigeration. In particular, highly ozone-threatening chlorofluorocarbons (CFCs) are being phased out, most quickly in wealthier countries.

CFCs not only damage ozone, they also have the highest global-warming potential. But all commonly used refrigerants are greenhouse gases, and every pound produced is destined eventually to escape into the atmosphere during manufacture, use, recharge, recycling, disposal.

Fifty-six percent of refrigerants worldwide are used for air-conditioning buildings and vehicles. North America, with 6 percent of the world's people, accounts for nearly 40 percent of its refrigerant market, as well as 43 percent of all refrigerants currently "banked" inside appliances and 38 percent of the resultant global-warming effects.

Finally, in counting costs, it's important to consider not only fuel and refrigerants but also the materials -- steel, copper, plastics and a lot more -- that have gone into building up the nation's colossal tonnage of air-conditioning capacity.

Heating up the economy

As a device explicitly designed to outrun the Second Law of Thermodynamics, an air-conditioner vividly illustrates the inevitable destruction caused by all economic activity, a process first described by Nicholas Georgescu-Roegen, the godfather of ecological economics.

Georgescu-Roegen wrote in his 1971 book "The Entropy Law and the Economic Process" that despite the neat, closed-loop flow charts depicted in textbooks, the economic process "is not circular but unidirectional. As far as this facet alone is concerned, the economic process consists of a continuous transformation of low entropy into high entropy, that is, into irrevocable waste."

Georgescu-Roegen went on to demonstrate the futility of growth-dependent economic systems, showing that in human societies, "production" is a phantom, that economic activity can be represented by just two factors: consumption of resources -- concentrated energy, useful materials and our ecological life-support system -- and elimination of useless or less useful wastes. When all is said and done, he argued, an economy's only product is nonmaterial "enjoyment of life," which can be banked only in the form of memories.

As it creates fleeting enjoyment through a state of low entropy (in this case, an island of coolness in a sea of heat) but only by increasing entropy at an even faster rate elsewhere (by using up fuels and materials and releasing useless wastes), air-conditioning is a poster child for the inevitable decay that, according to Georgescu-Roegen, is a defining characteristic of economic growth.

It's no coincidence that when the first modern central air-conditioning system was installed back in 1902, it was to cool the New York Stock Exchange.

Sweaty and sweatless sweatshops

Air-conditioning systems have been traditionally classified into two categories: "process" or "comfort." For the first half of the 20th century, process air-conditioning was emphasized, making a wide range of manufacturing industries possible on a large scale. The 1999 National Building Museum exhibit "Stay Cool! Air Conditioning America" noted that "manufacturers of products susceptible to heat and humidity -- tobacco, pasta, textiles, chocolate and color printing -- commissioned many pioneering experiments in mechanical cooling." The economic growth stimulated by such industries, and by the digital and biotech revolutions of more recent decades, could never have happened without massive doses of process air-conditioning.

Today, process AC systems account for less than 8 percent as much energy consumption as comfort systems. With the big shift from manufacturing to low-wage, white-collar jobs in the past two decades, more people than ever are working in environments with comfort air-conditioning. But in most manufacturing plants, air-conditioning is targeted only where needed, more to the benefit of equipment, inputs and products than of people.

Traditionally, humans have dealt with heat and humidity by cutting back on physical activity in the middle of the day, maybe even taking a siesta. That was before economic "competitiveness" became a universally accepted end in itself.

A story by a trade magazine on a South Carolina plastic sign factory where workers endured summer temperatures of 110 degrees listed the effects of such heat on workers' performance: inconsistency, inability to concentrate, negativity, drowsiness, headache, fatigue and vulnerability to accidents. The magazine noted that "deliberate work slowdowns, walkouts and similar job actions occur over heat problems more than any other workplace hazard."

Managers at the South Carolina plant considered and rejected heat stress remedies recommended by the Occupational Health and Safety Administration, such as allowing longer rest periods in a cooler area. They calculated that a single daily rest period of ten minutes for their 100-person work force would cost them $20,000 over a summer. As a cheaper remedy that wouldn't slow production, the company settled on large, high-capacity ceiling fans, which cost 1/28 as much as air-conditioning to install and 1/10 as much in electricity to run.

The employees would probably have preferred to have both the improved air circulation and more breaks from the heat, but no workers were quoted in the article.

In summertime office work, air-conditioning is ubiquitous. It's used because it improves productivity, but results can be unpredictable. A 2004 Cornell University study showed how uneven airflow in cooled buildings often leaves some workers sweating while others might be blowing on their hands to warm them. In the study, workers typed only half as fast at an air-conditioned 68 degrees as they did at 77.

On balance, air-conditioning doubtless stimulates production where it's used; otherwise, employers wouldn't bear the expense. But that cool, dry air also pumps up demand for goods, and that's where it really gets things moving.

Invigorating consumption

In describing the "Hot America" of the old days, the National Building Museum's exhibit painted a picture of a nation with sagging summer productivity, but more importantly, a nation with better things to do than to go shopping. It read in part,

Before air-conditioning, American life followed seasonal cycles determined by weather. Workers' productivity declined in direct proportion to the heat and humidity outside -- on the hottest days employees left work early and businesses shut their doors. Stores and theaters also closed down, unable to comfortably accommodate large groups of people in stifling interiors. Cities emptied in summers … Houses and office buildings were designed to enhance natural cooling, and people spent summer days and evenings on porches or fire escapes. They cooled off by getting wet -- opening up fire hydrants, going to the beach or diving into swimming holes.

A society that follows "seasonal cycles determined by the weather" is not an easy place to keep consumer demand calibrated to a constant, frenetic level. Movie theaters were among the first businesses to use air-conditioning, turning summer from a down-time into a boom-time. Now, almost all retailing depends on gathering large numbers of people into controlled environments and inducing them not just to buy what they came for but to "go shopping."

Marketing in America is an exceptionally wasteful means of extracting Georgescu Roegen's "enjoyment of life" out of valuable resources, and it's made possible partly by air-conditioning. In a summer without AC, the mall/big-box strategy of concentrated retailing would create little more than a hot stew of bodily aromas. With it, leisurely shopping has largely displaced noncommercial pastimes for many.

Air-conditioning can also make big purchases more attractive. You can't fully enjoy a jumbo-screen TV, a PC, an SUV or an RV unless you have AC. It allows you to grill steaks in the comfort of the kitchen, play indoor golf when it's too hot outdoors or, as President Richard Nixon used to do, enjoy your fireplace even in summer.

Redefining comfort

Have Americans just gotten soft, no longer willing to tolerate temperatures or humidities outside a narrow range? Maybe, but that's only part of it. The United States of 2006 is a product of the era of cheap energy, literally built for the air-conditioner, just as it's built for the automobile.

Lehigh University professor Gail Cooper documents how that happened, in her 1998 book "Air Conditioning America: Engineers and the Controlled Environment, 1900-1960." The post-World War II building boom, she observes, provided a golden opportunity to design buildings that would accommodate, even require, a central air-conditioning system, which at that time was a technological marvel in search of a market.

To make new buildings affordable despite the huge expense of cooling systems, homes were stripped of their heavier construction materials, large eaves, high ceilings, attic fans, and cross-ventilated design. (Cooper quotes the May, 1953 issue of Fortune magazine, which described the mass-produced home of the day as a "TV-equipped hotbox.") Office buildings became massive cubes; expensive, window-accommodating H- T- and L- shaped footprints were out. Extra insulation and other conservation measures were regarded as too costly; it wasn't the architects or builders who'd be paying the utility bills.

Much of that 1950s construction tradition has hung on throughout the Age of Air Conditioning. But change is coming -- slowly. By 2010, 5 percent to 10 percent of new, nonresidential construction is expected to be of certified "green buildings," which can be 30 percent more energy-efficient than standard buildings, while they use more ecologically friendly refrigerants. Part of the reduction in summer energy use can be achieved by use of natural ventilation, architectural shading and other built-in features. But making a serious dent in that 18 percent of all U.S. electricity consumption that goes to air-conditioning will require more than that.

No renewable energy source, and no combination of high ceilings, fans, rooftop gardens or other cooling strategies, can create the intensely cool, dry indoor climates to which most Americans have become accustomed in summer. Earth-friendly methods of construction and energy generation can provide some relief from the heat, but they cannot be expected to reverse the seasons. Summertime "comfort" will have to be redefined.

Meanwhile, the high standard that's been set for passenger comfort is helping doom efforts to run cars and trucks on alternative fuels. In 2005, air-conditioners in U.S. vehicles burned up the equivalent of the nation's entire fuel-ethanol production -- twice.

If the United States is going to get serious about the deep cuts in energy consumption that are needed, the whole idea of air-conditioning has to be questioned. In doing that, we can't depend only on ourselves, as individuals, to resist that most physically seductive of technologies. It will require big shifts in public policies that affect economic growth, achieved democratically rather than in quiet -- and artificially cooled -- White House meetings or raucous stock markets.

Part Two

America's Air-Conditioned Nightmare

Air-conditioning puts a chill on community spirit, aids the cause of anti-enviros, and just might have given us President George W. Bush.

In 1950, the string of nine coastal Sun Belt states from Virginia to Texas, plus New Mexico, Arizona and Nevada, had a combined population of 33 million, less than half the total population of the 14 New England and Rust Belt states that stretch from Maine to Minnesota. By 2002, the population of the 12 Sun Belt states had doubled and then grown by a third more, to 88 million -- almost as many people as then lived in those 14 northern states.

For many migrants, mild southern winters have always been the big attraction. But the price to be paid in summer discomfort is high. The "thermometer" below ranks the major cities across the two regions according to their average summer high temperatures. All of the hotter cities are in the Sun Belt, and all of those but Phoenix and Las Vegas can be oppressively humid in summer as well. All of the hotter cities gained population during the Age of Air-conditioning, while all of the cooler cities but New York lost. Percentage population gains are shown in green, losses in red:

Sunbelt stroke

Seats in the House of Representatives and electoral votes in presidential elections are re-allocated after each decade's census according to the relative populations of the states. In 1950, the 14 New England and Rust Belt states were apportioned 197 members in the House of Representatives, while the 13 Sun Belt states had only 96. Fifty years later, the northern states' membership had dwindled to 147, and that of the southern group had swelled to 132.

That net gain of 86 House seats by the Sun Belt over the more liberal group of northern states has had profound consequences. Of those northern states' current 175 seats in Congress (including both the House and Senate), 83 belong to Republicans, 90 to Democrats, and 2 to independents who vote mostly with the Democrats. The 13 Sun Belt states are represented by 106 Republicans and only 50 Democrats.

The effect of southbound migration on presidential politics has been even more dramatic. Each state gets as many votes in the Electoral College as it has votes in Congress. In 2004, the New England/Rust Belt states went 144-31 for Kerry (or 164-11 if you're not willing to concede Ohio's 20 votes to Bush), while the Sun Belt states went 156-0 for Bush.

Soon after the 2004 election, Hofstra University professor James Wiley wrote an op-ed titled "Blame air-conditioning for Kerry loss."

The headline overstates the case, and in the article itself, Wiley recognized that A/C was one of several factors behind the rise of the South. The economy of the Sun Belt boomed partly because that's where the government spent much of its military and aerospace budgets. The Solid South switched its allegiance from the Democratic to the Republican party not because Republicans promoted the air-conditioned lifestyle but because they appealed to race, sex, religion, and class prejudice, with an unhealthy dose of jingoism thrown in. That strategy has proven effective in the North as well as the South.

Still, the growth trajectory of the South and Southwest has closely paralleled that of the air-conditioning industry. Only a few thousand American homes had the technology in the late 1940s; 6.5 million had it by 1960; today, it's nearly universal in warm regions.

Shifting political ground

The economies of states in the humid Southeast and hot Southwest have grown twice as fast as those in the New England/Middle Atlantic/Great Lakes region in the Age of Air-conditioning, and that has shifted the political ground as well. There's no way the South could have become an economic powerhouse with high-rise cities and sprawling suburbs had there not been air-conditioning.

Visualize the CNN anchors coming on the air in Atlanta with flushed, sweat-streaked faces. Or Houston oil tycoons conferring with lawyers under whizzing ceiling fans, their documents held down by paperweights. The massive Sun Belt-bound exodus of jobs and the people to fill them probably would not have happened had we remained "Hot America."

The clout that came with that southward shift has two politically notorious centers of gravity: Texas (which has almost tripled in population since 1950) and Florida (which has grown to six times its 1950 population). But it has been felt everywhere. As Augustus B. Cochran III, professor at Agnes Scott College in Georgia, put it in his 2001 book "Democracy Heading South: National Politics in the Shadow of Dixie," the South has become more "Northernized" economically and culturally, while the North, and the nation as a whole, have become "Southernized" politically.

That has paved the way, Cochran writes, "for Southern politicians to assume national leadership roles and for traditionally Southern concerns and patterns increasingly to dominate American politics. The Southern metamorphosis is most striking, but it is the triumph of 'southernized' politics at the national level that bodes most significant for the future of democracy in America."

By now, you're thinking, What about sunny California? At the dawn of the Age of Air-conditioning, it was a distant second to New York in population, but it's now far and away the most populous state. It's so solidly Democratic that presidential candidates hardly bother to cast their shadows on its warm soil. Within the state, however, political and climatic differences mirror those of the nation. Currently, Democrats occupy 14 of the 18 House seats apportioned to northern California's Congressional districts, while only 19 of southern California's 35 districts are represented by Democrats. Kerry walloped Bush 63 percent to 37 percent in northern counties, but squeaked by with 51 percent in the south.

Of course, the importance of air-conditioning in California is not strictly a north-south matter; the farther you go inland from the coast, especially in low elevations and down south, the hotter it tends to get. Sure enough, the state's 2004 electoral college map shows mostly blue Kerry counties on the coast and red Bush counties inland.

Rise of the fríoconservatives

From the beginning, the mass movement to the Sun Belt was led by retirees in search of naturally warm winters and, for those who stayed year-round, artificially cool summers. Many registered to vote in their winter homes, and senior citizens are generally more conservative than average. In 2004, Bush won by his largest margin among voters over 60. Transplanted seniors have helped turn red states redder and blue states bluer, possibly with little overall effect on the national balance of power.

But people of all ages have been part of the southward migration, and it's been going on since the '50s. So a large proportion of Sun Belt voters in 2004 had spent most or all of their lives there and can be viewed not as immigrants but as products of the region's conservative culture (or in the Age of Air-conditioning, should we call it frioconservative culture?) Had they come of age instead in Milwaukee or Boston, no one knows how they would have voted.

As we have learned to our sorrow in recent years, individual states or regions can have wildly disproportionate clout in a country with a closely divided electorate and an 18th-century Electoral College system. In his "blame air-conditioning" op-ed, James Wiley calculated that if the relative populations of states (and therefore their Electoral College votes) had remained as they were in 1960, the actual state-by-state voting percentages would have sent Al Gore to the White House in 2000, and John Kerry in 2004.

Operating temperature

No experiment can be conducted to prove whether air-conditioning has tipped control of Congress or the White House to the Republican Party. But the nation's political predicament is wider and deeper than can be measured at the polls. As the Age of Air-conditioning has waxed, America's social and political climate has deteriorated -- among Democrats, Republicans and independents, from north to south -- and that deterioration can't be completely separated from the climate-control technology that grew along with it.

Imagine a country where economic life, by necessity, slows during the summer. Where potential customers stay home or go swimming on a hot afternoon, so salespeople are sent home early. Where factories simply shut down the line for a couple of weeks. That was this country before air-conditioning, but in 2006, it sounds like a distant, exotic land. In today's rapid-growth, high-consumption "service economy," workers and consumers, like computers and ovens, are components, each of which is maintained at an appropriate operating temperature.

Air-conditioners are not inherently right-wing devices. You'll hear them whirring all over Washington, D.C., this time of year, outside offices occupied by Republicans, Democrats and political groups across the spectrum, from the NRA to NOW and beyond. Only a tiny number of politicians, and no leading member of either major party, would dare put ecological limits ahead of short-term economics. Who's going to suggest that summer be a time to back off and simply not make, sell and buy so much stuff? None will dare say that a million and a half people have no business living and working in a place like Phoenix or that Miami has grown beyond supportable limits. And the ecological damage done by that refusal to slow the wheels of commerce is irreversible (see See Part I).

If it means keeping control of Middle Eastern and Central Asian oil and gas, the White House and most members of Congress have no problem calling for sacrifices: the prospect of a trillion dollars out of taxpayers' pockets, the blood of many thousands, the devastation of whole nations. But don't expect political leaders to ask that Americans save energy by sweating a bit more.

They certainly aren't asking themselves for any sacrifices. As Rep. John Murtha, D-Pa., a decorated combat veteran and harsh critic of the Iraq war, recently said of Karl Rove, "He's sitting in his air-conditioned office on his big, fat backside saying, 'Stay the course.' That's not a plan."

The political system is wilting partly because its roots have become shallow. People are becoming less and less inclined to gather spontaneously in noncommercial places, and air-conditioning reinforces that social chill. A shady suburban street on a pleasant 85-degree summer evening can be as free of human life as it might be during a Christmas Eve ice storm. Keeping people indoors and comfortable reinforces a tight focus on the individual or nuclear family rather than a larger community, and that is part of what's crippling grassroots political action.

Air-conditioning helps numb us to the prospect of ecological breakdown on a planetary scale as well. It's more tempting to think of global warming as a problem that only people in sweltering Bangladesh will have to deal with when we view their flood-prone plight from a seat in a cool living room or movie theater.

Handing ammunition to the energy hawks

Lack of toughness in dealing with summer heat and personal discomfort will make any efforts to kick the carbon habit seem just as feeble. Clinging to air-conditioning as a necessity is the best way to prove anti-ecological conservatives right when they dismiss renewable energy as inadequate. Better insulation and 'green' energy can never be enough to satisfy the nation's summer demand for A/C. Just to air-condition buildings -- and do nothing else -- would require eight times as much electricity from renewable energy as is currently produced.

In a paper published in the journal Science in 2002, a team of 18 leading energy researchers predicted what would be required to supply the world's expected energy needs in the year 2050 without adding carbon dioxide to the atmosphere. Finding, in the words of a press release announcing the article, that "no existing alternative energy source, nor combination of sources, currently exists that could adequately replace the energy produced by fossil fuels," they struggled to identify as-yet-undeveloped technologies that could supply the planet's needs, assuming per-capita consumption remains similar to today's.

Few of the strategies they considered -- including outlandish ones like a set of 660 photovoltaic solar arrays, each the size of Manhattan Island, placed in outer space -- appear likely to become reality. And, warned the authors, "the disparity between what is needed and what can be done without great compromise may become more acute as the global economy grows." The only effective approach will be to slash current energy consumption, especially where it is most wasteful.

Along with keeping cars parked, we could start by throwing open a few windows. The United States devotes 18 percent of its electricity consumption just to air-condition buildings. That's more than four times as much electricity per capita as India uses per capita for all purposes combined.

Producing that power for climate control in our interior spaces is playing a big role in distorting the planet's climate. To achieve the deep reduction in our greenhouse gas emissions that's going to be necessary, while insisting that we remain an air-conditioned nation, would take us into the realm of science fiction -- or maybe into a nuclear power-plant construction boom.

The nuclear option

Lacking political will to urge restraint or sacrifice, a growing number of lawmakers in both parties are considering the nuclear option. Conventional thinking seems to be leading mainstream environmentalists in the same direction. The venerable organization Environmental Defense is taking tentative first steps down that grim cul-de-sac. Here is its president Fred Krupp, speaking to NPR a year ago: "I think we have to have an open mind and certainly ask the serious tough questions about nuclear power that, um, need to be asked. And we should not just throw it off the table from the get-go."

The Natural Resources Defense Council (NRDC) has taken a similar position: that if fuel and wastes can be dealt with safely, "NRDC would not seek to exclude nuclear generation from competing on a level playing field with other reduced-carbon energy sources."

Luxuries like comfort air-conditioning are affordable only in a make-believe world with unlimited fossil fuel reserves and a method for pumping carbon dioxide into outer space (or unlimited tolerance for nuclear disaster and storage for radioactive wastes). In a greenhouse future, we will need every kilowatt we can squeeze out of wind machines, solar arrays, and biomass just to fulfill essential needs. None will be left over for cooling down the Astrodome.

If it now seems absurd to suggest that Americans give up air-conditioning, it's because we've become too used to living in the land of plenty. In her history "Air Conditioning America: Engineers and the Controlled Environment, 1900-1960," Gail Cooper tells how the U.S. government's War Production Board in May 1942 banned the manufacture or installation of air-conditioning systems "solely for personal comfort." Plans were even drawn up to remove the few existing comfort air-conditioning systems from commercial and government building for use in military production facilities.

The end of World War II and the economic boom of the 1950s brought a reversal of attitude that is still with us today. Cooper quotes one industry executive of the time who announced, "The problem has been one of selling the public on the idea that air-conditioning is no longer a luxury." But, says Cooper, that idea didn't require much selling: "Architects, builders and bankers accepted air-conditioning first, and consumers were faced with a fait accompli that they had merely to ratify."

If air-conditioning could be banned by the United States in wartime and then be declared a necessity in a time of abundance, we need not regard it as inevitable today. In an era when air-conditioning systems are proliferating, heating up the planet and chilling the social and political climate, their most important feature has become the "off" switch.

Stan Cox grew up in Georgia, migrated north against the flow, and is now a writer and plant breeder in Salina, Kan. (population 46,000; average July high: 93 degrees; 2004 election results: Bush 66 percent, Kerry 33 percent).