It was perhaps no coincidence that Pope Francis singled out air conditioning as an example of “harmful” consumption in his June 18 Environmental Encyclical, mere days before the Northern Hemisphere was fully into summer.
It turns out that air conditioning is a particularly pure example of how devilishly difficult it is to reconcile the intersection of human well-being, aspirational energy policies, and laws of nature.
The lengthy encyclical contains only one short paragraph with a single mention of air-conditioning amongst its 40,500 words. Here's what the Pope wrote:
““People may well have a growing ecological sensitivity but it has not succeeded in changing their harmful habits of consumption which, rather than decreasing, appear to be growing all the more. A simple example is the increasing use and power of air-conditioning. The markets, which immediately benefit from sales, stimulate ever greater demand. An outsider looking at our world would be amazed at such behaviour, which at times appears self-destructive.””
And here's what the Pope's advisors likely informed His Holiness: energy consumed just for air conditioning in America equals that used for all purposes by the countries of Mexico and Argentina combined.
Perhaps his advisors also noted that when the world's 169 emerging economies can finally afford to embrace air conditioning at the level used in the ‘west', their collective electric use will be 4,500 percent greater than all the electricity used for air conditioning in the United States.
Put another way—especially in the context of the same Encyclical's call to eschew fossil fuels—satisfying the entire potential demand of these poorer nations to cool their homes and hospitals, their food warehouses, factories and offices would require burning at least one billion tons more coal per year. (This assumes that coal's share of global electric supply is cut in half in the coming two decades — an economically improbable scenario.)
But far from being a “harmful habit” adopted because of marketing and profit motives, air conditioning in the developed countries grew exponentially because of its compelling benefits, Cooling is about far more than mere comfort (the pursuit of which itself is no sin), but also about its robustly documented economic and health benefits. Where there is no air conditioning because of power failures or poverty, death rates soar, especially among the most vulnerable. And where air conditioning finally takes hold, witness the history of the American South, economies flourish.
One can guarantee that emerging economies will follow the same pattern as the United States and, more recently, in China in the adoption of air conditioning. Even though Willis Carrier invented the modern air conditioner in 1902, fewer than 10 percent of American homes had one by 1965. However, by the turn of the century the penetration blew past 85 percent as the country got wealthier and air conditioning got cheaper.
In China, economic growth and a new, massive and low-cost grid (largely coal-fired by the way) enabled the share of homes with AC to grow from 1 percent in 1990 to over 60 percent today. Many more nations will in due course emulate this trajectory and pace, regardless of corporate marketing to “stimulate ever greater demand.”
We might hope to convince those in the mature economies to avoid the occasion of wasteful AC use in order to offset the inexorable and inevitable rise in energy use for AC elsewhere. Few would argue that there aren't excesses in consumption of many kinds across the wealthy nations. Yet even if the U.S. completely abandoned the use of air conditioning by having every single American return to awnings and fans, global electric use for AC would still more than double over the coming two decades.
Were Pakistan or Bangladesh, as just two examples, to satisfy their respective demand for air conditioning, each would consume twice the amount of electricity as the United States currently does for its cooling. India's potential AC power demand is 14 times greater than what America uses today for cooling. (The potential energy demand for each country comes from the combination of how hot it gets, how frequently it is hot, and the size of the population.)
Can any of this future demand be met by sources other than hydrocarbons? The rub here is that when it comes to air conditioning at such scales, the price and reliability of power really matter. While you can buy a small window conditioner for less than the price of smart phone, annual operating costs can easily exceed the purchase price. And that power will cost far more from alternatives to hydrocarbons. Energy policies that make electricity more expensive will certainly minimize power use from air conditioning because the poor won't be able to afford it.
So we are left with the final redoubt, which is to ensure air conditioners become far more efficient. Here we bump into the inconvenience of the laws of nature in our universe. As strange as it sounds, it takes heat to move heat, everywhere and always. The controlling law of thermodynamics is in a realm so immutably special that Einstein stated that it “is the only physical theory” that “will never be overthrown.” There is no Moore's Law (computer-like gains in efficacy) for energy machines. And even if air conditioners become twice as efficient as the best today—for which there is no known path—global energy use for air conditioning will still soar.
These same energy realities are inherent in the features of cars and computers too. But the air conditioner is not just “a simple example,” as Pope Francis wrote. It is the purest and least complicated example of realities immutability tied to rising prosperity and thus “increasing use” of energy in poor nations, which are mainly in the hottest parts of the world.
This piece originally appeared in Forbes.com