Jean-Philippe Hugues, left, fills a  store shelf with summer air conditioning products in Marseille, southern France, on July 3, where the temperature rose to  89.6F. (Claude Paris/AP)

The weather in Washington, D.C., and  Berlin, Germany, has been pretty similar recently. There is one striking difference between the two capitals, though: Whereas many Americans would probably never consider living or working in buildings without air conditioning, many Germans think that life without climate control is far superior.

The divide isn't limited to Berlin and D.C.: In fact, many Europeans visiting the U.S. frequently complain about the "freezing cold" temperatures inside buses or hotels. American tourists on the other side of the Atlantic Ocean, however, have been left stunned by Europeans' ability to cope with heat, even at work spaces or in their private homes.

Overall, it's safe to say that Europe thinks America's love of air-conditioning is actually quite daft. Europeans have wondered about this particular U.S. addiction for a while now: Back in 1992, Cambridge University Prof. Gwyn Prins called America's love of air-conditioning the country's "most pervasive and least-noticed epidemic," according to the Economist. And according to the Environmental Protection Agency, it's getting worse: American demand for air-conditioning has only  increased over the past decades.

The U.S. has been the world's leader in air-conditioning ever since, and it's not a leadership Americans should necessarily be proud of. According to Stan Cox, a researcher who has spent years studying indoor climate controlling, the United States consumes more energy for air conditioning than any other country. In many parts of the world, a lack in economic development might be to blame for a widespread absence of air-conditioning at the moment. However, that doesn't explain why even most Europeans ridicule Americans for their love of cooling and lack of heat tolerance.

Of course, Northern Europe is still colder than most regions within the United States and some countries, such as Italy or Spain, have recently seen an increase in air-conditioning. "The U.S. is somewhat unusual in being a wealthy nation much of whose population lives in very warm, humid regions," Cox told The Washington Post in an e-mail. However, the differences in average temperatures are unlikely to be the only reason for Europeans'  reluctance to buy cooling systems. It's also about cultural differences.

An aerial view shows people at a beach on the shores of the Silbersee lake on a hot summer day in Haltern, Germany, on July 4, 2015. (Ina Fassbender/Reuters)

Whereas Americans prefer an average temperature of 70 degrees, Europeans would consider such temperatures as too cold, Michael Sivak from the University of Michigan says. "Americans tend to keep their thermostats at the same temperature all year around.  In contrast, Europeans tend to set their thermostats higher in summer and lower in winter.  Consequently, while indoors, Europeans wear sweaters in winter, while American wear sweaters in summer," Sivak told The Washington Post.

Furthermore, Europeans are generally more used to warmer room temperatures because most of them grew up without any air-conditioning.

Another factor that may explain Europe's sniffy reaction toward American cooling is the continent's climate change awareness. According to a 2014 survey, a majority of Europeans would welcome more action to stop global warming. Two thirds of all E.U. citizens said that economies should be transformed in an environmentally-friendly manner. Cooling uses much more energy than heating, which is why many Europeans prefer sweating for a few days over continuously suffering under the effects of global warming in the future.

For sure, there are advantages of air-conditioned rooms even Europeans can't easily dismiss: Studies clearly show that cooling improves work efficiency during summers as well as sleep patterns, and even reduces mortality. So why would Europeans simply relinquish such advantages?

It turns out that refusing to use air-conditioning doesn't necessarily mean that one has  to sweat. E.U. regulations force companies to construct their work spaces more energy-efficiently, according to the New York Times. For instance, cool air can be pumped up from the underground, and walls can be made more resistant to heat from outside: Remember those thick brick walls most European homes are built with?

Moreover, air-conditioning in the U.S. may have more indirect but nevertheless dangerous impacts: Whereas Europeans have decided to simply accept the existence of hot days and nights, American architects have been forced to ban balconies and porches from many work spaces and to lower ceilings within buildings  to keep as much cold air indoors as possible, according to the Economist. In other words, whereas Americans might be more productive at work thanks to air-conditioning, they are also more likely to be stressed.

In the long run, America's air-conditioning addiction may also have another negative side effect: It will make it harder for the U.S. to ask other countries to continue to abstain from using it to save energy.

"The bottom line is that America's a big, rich, hot country," Cox told The Post. "But if the second, fourth, and fifth most populous nations -- India, Indonesia, and Brazil, all hot and humid -- were to use as much energy per capita for air-conditioning as does the U.S., it would require 100 percent of those countries' electricity supplies, plus all of the electricity generated by Mexico, the U.K., Italy, and the entire continent of Africa," he added.

That's not at all an unlikely scenario: In 2007, only 2 percent of Indian households had air-conditioning, but those numbers have skyrocketed since.  "The rise of a large affluent urban class is pushing use up," Cox explained.

"I have estimated that in metropolitan Mumbai alone, the large population and hot climate combine to create a potential energy demand for cooling that is about a quarter of the current demand of the entire United States," Sivak concluded in a paper published by the American Scientist.

"If everyone were to adopt the U.S.'s air-conditioning lifestyle, energy use could rise tenfold by 2050," Cox added, referring to the 87-percent ratio of households with air-conditioning in the United States. Given that most of the world's booming cities are  in tropical places, and that none of them have so far deliberately adopted the European approach to air-conditioning, such calculations should raise justified concerns.


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