Bili Buzz - Popular Science, Nature, Medicine, Archeology, Future & Myths

Fifty years after Sputnik, satellites peering down on Earth have become valuable scientific tools to study the global environment and offer much needed insight into the future of our planet.

One step forward, one step back.

The good news is that the ozone hole over Antarctica is slowly healing, thanks to controls on ozone-depleting substances that were once widely used in products such as refrigerators and aerosol cans. Stratospheric ozone protects us from harmful ultraviolet radiation that can cause problems such as skin cancer and crop damage.

Unfortunately, the recovery of the ozone hole has a dark side: The return of a thin, suspended blanket of stratospheric ozone will raise temperatures over the southern polar region, according to a new study by scientists at the University of Colorado at Boulder, the National Oceanic and Atmospheric Administration, and NASA Goddard Space Flight Center. The scientists, who relied on a NASA computer model for their predictions, also report that the healing of the hole will weaken winds that currently shield the Antarctic interior from warmer air masses to the north.

Antarctica may not be the only continent affected: The researchers also found that the changes in air circulation caused by ozone recovery could mean wetter conditions during late spring and early summer in southern South America, and warmer and drier weather in Australia—which is already suffering from a long drought.

While average temperatures in most places on the globe have been increasing, the interior of Antarctica has experienced cooler summers and autumns. “We may finally see the interior of Antarctica begin to warm with the rest of the world,” says Judith Perlwitz, the lead author of the study, which will be published in the journal Geophysical Research Letters on April 26.

The waters around Antarctica are an anomaly; they’re home to a marine ecosystem straight out of the Paleozoic era (the period spanning from 541 million to 251 million years ago). But global warming is about to change that, according to research presented today at AAAS. The reason for the preponderance of ancient organisms is the cold water: Predators that are capable of breaking the skeletons of their prey—modern fish, sharks, skates, and so on—simply can’t live there. In fact, the most vicious predator in the Antarctic marine ecosystem right now is either a big sea star or an acid-oozing worm.

Those waters are warming, though, and possibly faster than the rest of the world’s oceans. This threatens to bring predators capable of wiping out the ecosystem’s ancient creatures, rendering it no different in composition than the rest of the ecosystems around the world. Why is this a big deal? “The reinvasion of predators after millions of years will dumb down the ecosystem,” says Richard Aronson of the Dauphin Island Sea Lab. Yet another instance of how climate change is robbing the world of its biological diversity.

For more reports from the annual AAAS conference, click here.