'Tomorrow's' forecast: bad science on the big screen

If this were the Weather Channel, who would watch anything else? Four simultaneous tornadoes rip through L.A. Hail like grapefruit pelts Tokyo. Snow blankets New Delhi. Continent-sized storms plunge North America, Europe, and Asia into an ice age.

Welcome to the world according to "The Day After Tomorrow," Hollywood's latest natural-disaster offering. At heart, it's a polemic on climate change with blockbuster special effects and a few plot twists from past disaster movies - teen love forged in struggle and workaholic scientist saves neglected son.

But even if the movie gets passing marks for entertainment and is stirring the political caldron, it flunks Climate 101. And in the process, it runs the risk of trivializing as mere entertainment a problem that many researchers say is quite serious.

Global warming "is a real problem and people need to be educated about it," says Peter Stone, a professor of atmospheric dynamics at the Massachusetts Institute of Technology who attended an advanced screening of the film in Boston. But the film's errors and exaggerations "make it an easy target to shoot at," he adds, and could leave an impression that the issue as a whole is an exaggeration.

Let's pause here to note that scientists long have taken delight in pointing out foibles in disaster and science-fiction movies and TV shows. Even the film "Troy" has drawn withering comments from reviewers in the current issue of Archaeology magazine.

But "The Day After Tomorrow" goes astray with its basic premise, says Wallace Broecker, a geochemist at Columbia University widely credited with discovering signals of rapid climate change in Earth's geological record. "The whole scenario of global warming turning on an ice age is almost certainly wrong."

In the movie, global warming melts the Arctic ice cap, fresh water shuts down critical currents in the North Atlantic that transport heat north, and the big chill begins. The impetus for that scenario comes from Dr. Broecker's early work on a 1,000-year chill-down known as the Younger Dryas, which occurred at the end of the last glacial period. Yet recent studies have shown that at the time, sea ice covered virtually the entire northern Atlantic Ocean.

Today, the climate is far too warm to support such extensive amounts of ice. To shut the circulation down under today's conditions, he says, simulations indicate that global average temperatures would have to rise by 4 to 6 degrees. This would generate enough rainfall and river runoff to freshen the North Atlantic sufficiently to halt the "conveyor." But given current trends, he adds, it could take 70 to 100 years to get to that point - not 10 days, as the movie suggests.

For MIT's Dr. Stone, a brief exchange between Jack Hall, the scientist-hero, and a British colleague Terry Rapson nearly sent him running for the door.

The two celluloid scientists stare at computer images of the superstorms, each with a sinister hurricane-like eye. Rapson describes how the storms draw "supercooled" air from the upper atmosphere through the eye to the ground, flash freezing anything underneath.

Wouldn't the air heat up as it flows down into the eye? Hall asks.

Right question.

No, Rapson replies, because it's flowing too fast.

Wrong answer, Stone says. As air moves down into the eye, it gets compressed by more air flowing down from aloft. Air heats up when compressed.

"It's absurd," Stone sighs. "This is basic physics that has nothing to do with projections of global change."

Even from a policy standpoint, the film assumes all would have been well if the president had acted when Hall's first warnings were sounded. Yet in the real world, Washington often follows rather than leads, notes Eileen Claussen, who heads the Pew Center on Global Climate Change. She notes that a number of states are taking innovative approaches to cutting greenhouse gas emissions. [Editor's note: In the original version, Claussen's name was misspelled.]

"A lot of people at the state level are looking at this as a problem that will affect them, and they're taking action themselves," she says - including some key Republican governors.

Of course, everyone from the movie's director and producer to groups on both sides of the issue agree that "The Day After Tomorrow" is a bit over the top.

"Tie advocacy too closely to this, and it looks ridiculous," says Richard Morrison, a spokesman for the Competitiveness Enterprise Institute in Washington. Nevertheless, the organization, which opposes efforts like the Kyoto Protocol to limit greenhouse-gas emissions, is taking an active role in debunking the movie.

On the liberal side, former Vice President Al Gore, Robert F. Kennedy Jr., and groups such as MoveOn.org have declared the film valuable for the attention it focuses on climate change.

In the end, if Hollywood truly wants to turn films into educational opportunities, it would hire independent experts to design packages for schools to be used in conjunction with the film, scientists say.

Actually, Dr. Claussen points out, the film's DVD is slated to contain an hour-long segment with real scientists comparing the movie with current research.

Pass the popcorn.