Suppose you're a malevolent engineer trying to design a grave threat to Earth. Your aim is to create a force that does plenty of damage by stealth, somehow evading the attention of the governments who might otherwise frustrate your plans. Well, it turns out that the threat you're looking for already exists, and its name is global warming. Ninety-eight percent of experts agree that the globe is warming, that humans are contributing to the effect, and that our failure to act now will contribute to death, disease, injury, heat waves, fires, storms, and floods. Despite these dire forecasts, Barack Obama and Mitt Romney -- both of whom believe in human-driven climate change -- conspicuously omitted global warming from this year's menu of election issues.
What is it about human psychology that makes meteor strikes and volcanoes so compelling, while global warming languishes as a political afterthought? The answer has many strands, but I'll focus on three, beginning with The Hollywood Test. According to The Hollywood Test, the content of our culture's films reflects our most vivid fears. Over the past several decades, Hollywood producers have funded dozens of big-budget disaster films. In descending order of frequency, those films depicted alien invasions (approximately 100), epidemic and pandemic outbreaks (37), tsunamis and destructive waves (20), earthquakes (16), volcanoes (14), and meteor, asteroid and comet strikes (14). Absent from the list is a scintillating portrayal of global warming, though two films, The Day After Tomorrow and Lost City Raiders, described global warming as the catalyst for floods, tornadoes, hurricanes, and a protracted Ice Age. Al Gore's important documentary film, An Inconvenient Truth, is perhaps the only film that focuses squarely on global warming, and then it's long on information, and short on Hollywood stars and scenes of graphic devastation. And that sums up the first major problem with global warming: its precise consequences aren't vivid enough. Humans are better at focusing on the moderate, specific, localized devastation of a major earthquake than on the great but murky devastation that global warming will bring in the middle part of the 21st century.
One of the best illustrations of this difficulty comes from research in a different domain: on our willingness to contribute to charitable causes. In one experiment, people were asked to donate money to save either one sick child -- accompanied by a photo -- or eight sick children accompanied by a similar group shot. All else being equal, eight children clearly deserve more help than a single child, but the single child tugged more insistently at the would-be-givers' heartstrings, eliciting an average donation that was 77 percent higher than the average donation given to the group of eight. The pain of a single child -- a Baby Jessica down the well, for example -- has the emotional resonance of an erupting volcano or a hurtling asteroid, while the deaths of literally millions of malnourished children in Africa and Asia inspires the same muted response that we allocate to global warming.
The second problem with global warming is that it progresses too slowly. The globe continues to warm while we're responding to fast-arriving Hurricane Sandy, tending to our wounds after devastating earthquakes in Haiti, Japan and Chile, and cleaning up after tornadoes in Joplin, Mo., and Greensburg, Kan. There will always be more pressing issues on the table, so politicians prefer to focus their time on disaster relief, fiscal cliffs and health insurance.
People just aren't engineered to take slow-moving threats seriously. We're a bit like the fabled frog in a pot of water on the stove, who sits by idly while the water's temperature slowly rises to boiling point. The frog in this apocryphal tale doesn't realize he's cooking because the water heats too slowly to register on his danger-detecting radar. The analogy to humans sitting by while the planet warms couldn't be more obvious. But imagine instead if this century's warming and its attendant storms, droughts, heat waves, and floods were condensed to occur by the end of 2012. We'd have very little time to do much to minimize the damage, but the world's presidents, prime ministers, and hundreds of millions of coastal residents would have no choice but to prepare for the worst.
Bound up in this second problem is a third: that although temperatures are rising in the long run, there's plenty of daily and seasonal noise that occludes that rise. We'll continue to have freakishly cold days even as the planet's average temperature rises. For example, the hottest 16 years between 1880 and 2010 all occurred between 1995 and 2010, though during the same period of time the following countries experienced their coldest days on record: South Africa, Nepal, Bangladesh, Finland, Germany, Italy, Chile, Paraguay, Philippines, Mexico, Cuba, Antarctica, Northern Ireland and Scotland. So while Earth's average temperature rises, we continue to experience isolated pockets of very cold weather.
We're also approaching winter in the northern hemisphere, and it's very difficult to imagine a warm summer day when it's cold outside. In one study, psychologists Jane Risen and Clayton Critcher approached people outside and asked them whether they believed in global warming. The temperature on those days varied from quite chilly to very warm, and people were far more likely to believe in the concept of global warming on warmer days. In fact, knowing the ambient outdoor temperature predicted their beliefs in global warming just as effectively as knowing whether they were politically liberal or conservative. Of course that doesn't make sense at all: the temperature on one cold wintry day shouldn't change whether you expect the temperature of the planet to rise on the whole by 2050, almost 14,000 days in the future.
So global warming is the perfectly designed threat-by-stealth. Its murky consequences aren't vivid enough to impress our distracted brains, they're set to approach too slowly to command much attention while there's still something we can do to stop them, and the earth's temperature rise is peppered with winters and freakishly cold days that distract from the unmistakable warming trend. If global warming were the work of an evil engineer, he'd deserve congratulations on a job well done.