‘Day After’ scenario is fiction,
but climate concerns are fact

by Tom Parisi

The movie is based on more fiction than fact, but NIU geologist and climate-change expert Ross Powell nonetheless gives a “thumbs up” to the disaster flick, “The Day After Tomorrow.”

Powell is thrilled that Hollywood is bringing attention to the issue of global warming. “The Day After Tomorrow” ranked second at the box office over the Memorial Day weekend.

“Global warming is a very real concern,” Powell says. “But the scenario that plays out in the film – where our planet is plunged into an instant ice age – couldn’t happen. When scientists talk about a concern over abrupt climate changes, we’re not talking about changes that would occur over days, but rather over decades. That is a real fear. Even if the changes are not instantaneous, they still may provide significant problems for us to deal with.”

Powell says scientists have collected strong evidence that while our climate system has been behaving naturally in the past, abrupt climate changes have happened over decades.

“Today we have solid evidence that human activity has changed the composition of the atmosphere as well, which complicates things,” he says. “We don’t know where trigger points are in the climate system that may instigate another abrupt change.”

The Intergovernmental Panel on Climate Change (IPCC) has projected a rise in global temperature, mostly because of greenhouse warming, of between 1.4 degrees and 5.8 degrees Celsius by the end of this century. The warming expands the world’s oceans and melts glaciers, thus raising sea levels.

“If the IPCC projections of warming trends are correct, the world’s climate within the next few centuries will be at a point equivalent to conditions on Earth tens of millions of years ago, before Antarctica became cold enough to support the big ice sheets that are there today, and which have survived for over 35 million years,” Powell says.

“Sea levels are already rising on the order of millimeters a year—that’s well documented. If the trend continues at that rate or faster, eventually coastal cities from Venice (Italy) to New Orleans are going to have to do something to mitigate the rise.”

Arctic regions of the planet already are experiencing problems. “In Alaska, for example, two villages have been abandoned because of erosion from the sea,” Powell says. “The sea ice, which for generations protected waves from crashing ashore in those villages, has melted. Other coastal regions in Alaska face similar problems.”

Continued global warming also could influence everything from agriculture and air quality to energy usage to the spread of disease, Powell adds.

Since the 1970s, Powell has worked extensively on global warming issues. He is helping lead a new multi-million-dollar, international drilling initiative in Antarctica, where scientists will study geological climate records buried beneath the frozen sea to predict global warming trends in the future. The project, dubbed ANDRILL, short for Antarctic Drilling, is projected to last for at least 10 years.

Beginning in 2006, the scientists will drill deeper than ever before in the area – more than half a mile into the Antarctic seabed – tapping into a geological record of time as far back as 70 million years, when dinosaurs still roamed the planet and few, if any, glaciers existed.

Core samples taken from within the Antarctic seabed provide a layered record that scientists can read like a history book. The samples contain fossils and sediment left behind during repeated advances and retreats of the ice sheet, which were governed by climate shifts.

6-14-04