Stray IVY

by Dr. Jeffrey M. Masters
Chief Meteorologist, The Weather Underground, Inc.

The disaster film epic, The Day After Tomorrow™, depicts a world where global warming triggers an abrupt climate change, creating a global superstorm that unleashes unimaginable worldwide weather disasters. In the span of just a few days, tornados devastate Los Angeles, huge hail pounds Tokyo, and colossal storm surge waves and blizzards whip New York. Could it really happen? Could global warming really cause such incredible disasters?

Like much science fiction, The Day After Tomorrow™ is based on some solid scientific fact. Recent scientific discoveries show that the present day climate is unusually stable, and that "normal" climate for Earth is the climate of frequent extreme jumps--like a light switch flicking on and off. Thus, the popular conception that global warming will lead to a slow and steady increase in temperature that humans can readily adapt to may be incorrect. Global warming could push the climate system past a threshold where a sudden, irreversible climate shift would occur. This would most likely happen if the increased precipitation and glacial melt water from global warming could flood the North Atlantic with enough fresh water to slow down or even halt the mighty Gulf Stream ocean current. Without the Gulf Stream pumping warm, tropical water to the North Atlantic, average temperatures would cool in Europe and North America by 5癋 or more in just a few years--not enough to trigger a full-fledged ice age, but enough cooling to bring snows in June and killing frosts in July and August to New England and northern Europe, such as occurred in the famed "year without a summer" in 1816. In addition, shifts in the jet stream pattern would bring about severe droughts and damaging floods in regions unaccustomed to such events, greatly straining global food and water supplies. Climate experts consider a sudden global warming-induced climate shift unlikely in the next 100 years, but do acknowledge their computer models are too crude to know just what the probabilities are.

But no, a sudden global warming-induced climate shift could not cause the kind of instant wild weather mayhem depicted in the movie. In this respect, The Day After Tomorrow is science Fiction with a capital "F". The laws of meteorology get seriously abused here. Consider the book the movie is based on, The Coming Global Superstorm, by Whitley Streiber and Art Bell. Whitley Streiber is a UFO expert and author of the best-selling 1985 book Communion, a non-fiction account of his abduction by extra-terrestrials. Art Bell hosts a nationally syndicated all-night radio show, Coast to Coast AM, which specializes in UFOs and the supernatural. They argue that a sudden climate shift would create such strong atmospheric instability that an incredible "superstorm" must result. Powerful clusters of thunderstorms in the Arctic would penetrate deep into the stratosphere, bringing -150癋 upper atmospheric air to the surface, flash freezing any living thing caught outside. The clusters of thunderstorms would merge into a continent-sized "superstorm" that would suck energy from the oceans heated by global warming, generating winds of 100-200 mph, blizzard conditions with hundreds of feet of snow, temperature falls in Canada of 100 degrees in an hour, and incredible thunderstorms with huge hail and tornados.

The primary scientific evidence Streiber and Bell offer to support their intuition involves the discovery of wooly mammoths with partially digested plant remains in their stomachs: "The sudden freezing that killed these animals required much more than a bad storm. It required a storm that was capable of delivering unprecedented levels of extreme cold to the surface and doing it so suddenly that the animals which were caught placidly grazing, did not even have time to look up.... To all appearances they were simply frozen solid where they stood without enough warning to do more than raise their heads." It takes a pretty talented scientist to infer the existence of "superstorms" from the appearance of how a frozen animal held its head, especially when ice core, sediment core, and tree ring studies all show no evidence of historical superstorms. But Bell and Streiber are not scientists, and certainly didn't run any computer models of the atmosphere to verify their theories. Modern computer models of the Earth's weather show that the only types of storms planet Earth can manage are the current ordinary hurricanes, blizzards, and thunderstorms. The formation and evolution of the superstorm as described in The Day After Tomorrow and The Coming Global Superstorm is a meteorological impossibility. Let's summarize just a few of the scientific impossibilities in the movie: