In Box

Terror Management

Could a shared fear of climate change unite enemies?

Reflecting on U.S.-Soviet relations late in his presidency, Ronald Reagan once mused about one thing that could unite humanity: a threat from a "power from outer space." At the time, the sci-fi reference seemed a little out of place in a discussion about international relations, but the Gipper had a point: Bitter rivals don't tend to unite unless they face a common threat from a third party. Think of the U.S.-Soviet alliance against Nazi Germany, the period of bipartisan consensus that followed the 9/11 attacks on the United States -- or, more to Reagan's point, the now clichéd scene of mortal enemies putting aside their differences in alien-invasion movies. (Remember the Arab and Israeli pilots who join forces near the end of Independence Day?)

Some psychologists, however, now suggest we may not have to wait for flying saucers in our search for a global threat that can bring humanity together -- we may already have created one ourselves in the form of hotter temperatures, rising sea levels, and increasingly unpredictable weather. According to a recent article in Peace and Conflict: Journal of Peace Psychology, just hearing about the dangers posed by global warming can turn you into a pacifist.

The study was led by University of Colorado professor Tom Pyszczynski, one of the leading proponents of an emerging school of social psychology known as "terror management theory," which holds that a wide array of human behavior and thought is motivated by fear of death. In this case, a common fear of the dangers of climate change, he argues, can lead to global cooperation. "When you think of yourself as facing a shared enemy and a shared threat, it brings people together," Pyszczynski says.

Ironically, defense strategists have been warning for years of exactly the opposite scenario when it comes to global warming: that a new world of extreme weather and rising seas could usher in a new age of confrontation as countries compete for increasingly scarce resources and habitable land. More recently, a 2012 report by the U.S. National Intelligence Council forecast that, by 2030, climate change could spawn this kind of conflict in developing and fragile states.

Still, Pyszczynski is no starry-eyed optimist. "My guess is that as things get worse, people will come together and a consensus will emerge, but by then it may be too late," he says. Then again, in disaster movies enemies always unite just in time to fight off the bad guys.

Chris Hyde/Getty Images News

In Box

Life After Death

How the plague made modern Europe.

Ask someone to identify the foundations of modern Western civilization, and expect to hear the Renaissance, the Enlightenment, or the Industrial Revolution. But as watershed periods in the development of Europe, all three may pale in comparison to the Black Death. According to economists Nico Voigtländer and Hans-Joachim Voth, the 14th-century plague -- which wiped out between one-third and one-half of the continent's population -- may have been the factor most responsible for producing European prosperity.

The question Voigtländer and Voth take on in an article for the Review of Economic Studies has long vexed historians: How did Europe go from a global backwater around 1400 -- defined by political fragmentation, poverty, and widespread illiteracy -- to the most prosperous region the world had ever known by the dawn of the 18th century?

It wasn't primarily new ideas or technology, the authors argue -- it was the plague. According to their logic, incomes should fall as populations rise, barring a major increase in available resources. Conversely, when a population decreases due to war or disease, incomes go up as there's more available land and labor becomes scarce.

The effect is usually temporary. But the population shock of the Black Death was so dramatic that it caused a permanent increase in incomes -- an estimated 30 percent in Western Europe between 1500 and 1700. The authors note that China, in terms of farm wages, urbanization, and economic output, was pretty much on par with Europe when the Black Death hit. Had Europe's population continued to grow unchecked during this period, Voigtländer says, it would have been at about the development level of China in 1700. Instead, Europe by 1700 had raced far ahead, setting the stage for its next breakthrough: the innovation and rapid increase in trade that began during the Industrial Revolution decades later.

What does this mean for today? Thankfully, few mass-casualty events on the scale of the plague have occurred in recent centuries. Plagues act as what Voth calls a "neutron bomb," removing people but relatively little in the way of economic capital (unlike, say, the two 20th-century world wars, which caused massive property damage and tens of millions of deaths).

The closer parallel may be AIDS. A 2005 article in the Quarterly Journal of Economics by Alwyn Young argued that high death rates from HIV could lead to higher incomes in South Africa. Another parallel might be modern China, whose recent growth has been aided by a draconian one-child policy that prevented hundreds of millions of births over the last three decades.

Fortunately, no one's yet gone all apocalyptic when searching for a solution to Europe's current economic woes.