Long Droughts, Rising Seas Predicted Despite Future CO2 Curbs
By Juliet Eilperin
Condensed by Native Village

Scientists predict the greenhouse gas levels expected by 2050 will cause devastating droughts and a sea-level rise that will last for 1,000 years. They also say we can't prevent it, no matter how well the world curbs carbon dioxide emissions,

"I think you have to think about this stuff as more like nuclear waste than acid rain: The more we add, the worse off we'll be," said scientist Susan Solomon, a member of the international team of scientists.  "The more time that we take to make decisions about carbon dioxide, the more irreversible climate change we'll be locked into."

Carbon concentrations in our atmosphere stand at 385 parts per million. While some climate scientists hope  to end the climb at 450 ppm, current projections say those numbers will be 550 ppm by 2035 and after that will rise by 4.5% per year.

The new study projects that if CO2 concentrations peak at 600 ppm, several world regions will face major droughts as bad or worse than the 1930s Dust Bowl. This includes southwestern North America, the Mediterranean and southern Africa.

By 2003, global sea levels will rise by about 3 feet. This does not factor in melting glaciers and polar ice sheets which will add significant sea level rises. 

Even if the world could stop carbon dioxide buildup at 450 ppm, the subtropics will still experience a 10% decrease in precipitation. At 600 ppm, it will be a 15% decrease. The already parched U.S. Southwest would  see a 5% drop in precipitation during its dry season.

Mary-Elena Carr from the Columbia Climate Center called the new projections "very sobering."  While some adaptations can be made, the ability to cope with such severe droughts is limited. "When it's drought, that is hard, because we have a finite amount of water and a growing population we need to feed,"

Severe storms caused by higher sea levels also pose a dangerous challenge to large populations. It is predicted that earth's geography will change as coasts and islands become submerged.

Scientists say the world's oceans are already absorbing an enormous amount of carbon, but will reach their limit. As this happens, the atmospheric temperature will remain nearly constant.

CO2 emissions account for only about half of human-induced global warming. Several other gasses including methane, affect the climate. 

A separate study suggests that the Antarctic's emperor penguins will be extinct by 2100 if sea ice shrinks by the predicted amounts. Emperor penguins would have to migrate or change the timing of their growth stages to avoid extinction but "evolution or migration seem unlikely for such long-lived species at the remote southern end of the Earth," one scientist said.

Both studies are published in this month's "Proceedings of the National Academy" of Sciences,

http://www.washingtonpost.com/wp-dyn/content/article/2009/01/26/AR2009012602037_pf.html