The big chill: how air conditioning changed the world

It gave us higher obesity rates, better sex, and George W. Bush
Stephanie Rausser / Getty Images

Some of the most significant events in recent decades—the election of George W. Bush as president, for example, or the assassination of JFK—would never have happened had it not been for one, seemingly innocuous invention: air conditioning. Without it, says Stan Cox, author of the forthcoming book Losing Our Cool: Uncomfortable Truths About Our Air-conditioned World (and Finding New Ways to Get Through the Summer), “History would have been different.”

Losing Our Cool is the kind of book we’ve seen a lot of lately—like Cod: A Biography of the Fish that Changed the World, or Sugar: A Bittersweet History—that ascribes momentous consequences to otherwise mundane things. In the case of air conditioning, it’s true: this invention has changed how people live, determined the population patterns of entire continents, and affected everything from when we have babies to why we feel so tired in the morning. It’s gone from being a salvation, literally sparing lives, to a possible health risk to an environmental demon because it could alter the planet’s climate.

Cox reveals that just about every modern trend—including obesity and suburbanization—can be explained, at least in part, by air conditioners. It’s also a source of tension, sometimes perversely so: people often complain about feeling too cold inside.

That we dare grumble shows how unselfconscious we’ve become about air conditioning consumption. In Dubai, the world’s first air-conditioned beach has been proposed, which would feature coolant pipes beneath the sand and giant blowers to simulate ocean breezes. Closer to home, we boast air-conditioned golf carts and even storage facilities. We sermonize about the importance of turning off the tap while brushing our teeth, and not letting the car idle too long, but to suggest cutting down on air conditioning is akin to taking away heat in the winter or water in the desert. “Society as a whole,” Cox told Maclean’s, “is addicted to it.”

No one more so than North Americans. The amount of energy consumed by running residential air conditioners in Canada almost tripled between 1990 and 2007—52 per cent of Canadians have central air conditioning, and that figure rises to 80 per cent in Ontario, according to Natural Resources Canada. In the U.S., residential energy consumption for air conditioners nearly doubled between 1993 and 2005. In fact, Americans use as much electricity for air conditioning as all of Africa uses for everything.

The effects of this are far-reaching. In sweltering Sun Belt states such as Arizona, Nevada and Texas, it’s no overstatement to say air conditioners made life possible. “It’s inconceivable that there would be a Florida of 18.5 million people today without air conditioning,” says historian Gary Mormino in Losing Our Cool. After the Second World War, droves of Americans moved from chilly northern states. This demographic shift exactly mirrored the proliferation of air conditioners across the country. “Air conditioning was essential to the development of the Sun Belt,” says Mormino. “It was unquestionably the most significant factor.”

That population boom gave southern states considerably more influence in the electoral college, the body of voters who hold the key to the White House. “In 2000 or 2004,” Cox told Maclean’s, “if we had had the population distribution of the 1950s, George W. Bush would not have won.” If in 1960 there had been as many people living in the Sun Belt as there are now, he continues, “then Kennedy would not have won. Richard Nixon would have been president.” And JFK, at least in theory, would never have been the target of a deranged shooter.

Unlike politics, air conditioning has a place in the bedrooms of the nation. Temperature has long been the dominant influence on birth patterns; the hotter it gets, the less interested people are in sex. Demographic studies in the States have shown that for every 10 degrees the average monthly temperature rises, conception rates decline by up to 10 per cent. But since the rampant use of air conditioning, this trend has been flattened, which Cox believes demonstrates “the power that a human invention like air conditioning has to mould the biological patterns of life.” What’s more, he explains, cool temperatures enhance the viability of sperm, further enabling fertility. As one advertisement in India quipped, air conditioners are great for “improved performance in the bedroom.”

Air conditioning even explains morning sluggishness. A 2006 Japanese study showed long-term exposure can delay our daily dose of invigorating hormones until 10 a.m. or later. That’s because air conditioners are one of the best sleep aids. So much so that they may disrupt cortical rhythms, which awaken and energize us. Air conditioning also contributes to weight gain because, as a Danish study found, individuals eat more in cool environments. Plus, with air conditioners, our bodies convert more energy from food into fat because we don’t need to use it to chill off.

If predictions about climate change are correct, air conditioning could become even more crucial. Forty years from now, researchers predict the earth will experience 17 to 23 per cent more hot weather annually—and taking population growth into account, demand for cooling systems will rise by 65 to 72 per cent. As the climate warms, Cox points to research suggesting that malaria-carrying mosquitoes will expand their geographic range from tropical areas to the north. Already, the Asian tiger mosquito, which can spread dengue fever, has arrived in the southeastern States. Soon, we’ll need air-conditioned places just to escape diseased pests.

It’s a dizzying cycle. “As it gets hotter,” Cox explains, “we’ll become more dependent on air conditioning, which will feed the heating of the planet, and create even more demand for air conditioning. Where is it going to stop?” According to the “adaptive model of comfort,” our bodies are good at getting used to cool, dry temperatures, and within days, warmth becomes insufferable. That’s why Cox, 54, hasn’t used an air conditioner at home in decades, even though he owns one. Cox relates to a woman he once heard describe it this way: “We don’t use the air conditioner because it makes it too hot outside.”

As our heat tolerance declines, “nature deficit disorder” sets in. Air conditioners have all but displaced the need for shady trees to cool us down. Whereas homes used to feature big awnings and porches, and many windows for cross-drafts, now they’re built around air conditioners—and windows are sealed shut. Inadequate ventilation is linked to asthma and allergies. The suspected culprits, writes Cox, include “volatile organic compounds, moulds, and allergens in floor dust,” and bacteria, which air conditioners harness inside their coils and drip pans, and disperse.

Of course, air conditioners have also saved untold lives during heat waves, emphasizes Cox, who is also a senior scientist at the Land Institute, an agricultural research centre in Salina, Kan., and have enabled the very existence of hospitals and production of drugs. In this way, air conditioning is the ultimate paradox. It cools us, but makes our planet hotter. It encourages us to have sex, but makes us slow and heavier. It keeps us breathing when it’s suffocatingly hot, but invites deadly species to attack us.

The irony isn’t lost on Cox, who acknowledges there’s no going back. While writing Losing Our Cool, it got to the point where he was reluctant to tell people about the book. “I’d either get a blank stare like, ‘Why would you write about that?’ or a wide-eyed fear like, ‘No, you’re not going to take that away from me, are you?’ ” recalls Cox. It reminded him of an old gun-lobby slogan. “You can have my air conditioner,” muses Cox, “when you pry it from my cold, dead hands.”