Climate of Our Future

Americans Consider Global Warming An Urgent Threat, According To Poll

Science Daily — A growing number of Americans consider global warming an important threat that calls for drastic action, and 40% say that a presidential candidate’s position on the issue will strongly influence how they vote, according to a national survey conducted by Yale University, Gallup and the ClearVision Institute.

“One of the most surprising findings was the growing sense of urgency,” said Anthony Leiserowitz, director of the Yale Project on Climate Change and the study’s principal investigator. “Nearly half of Americans now believe that global warming is either already having dangerous impacts on people around the world or will in the next 10 years–a 20-percentage-point increase since 2004. These results indicate a sea change in public opinion.” Keep reading

2007 Ozone Hole ‘Smaller Than Usual’

Science Daily — The ozone hole over Antarctica has shrunk 30 percent as compared to last year’s record size. According to measurements made by ESA’s Envisat satellite, this year’s ozone loss peaked at 27.7 million tonnes, compared to the 2006 record ozone loss of 40 million tonnes.

Ozone hole over Antarctica measured in September 2007 by Envisat. The ozone loss in 2007 peaked at 27.7 million tonnes, compared to the 2006 record ozone loss of 40 million tonnes. (Credit: KNMI - ESA)

Ozone loss is derived by measuring the area and the depth of the ozone hole. The area of this year’s ozone hole – where the ozone measures less than 220 Dobson Units – is 24.7 million sq km, roughly the size of North America, and the minimum value of the ozone layer is around 120 Dobson Units.

A Dobson Unit is a unit of measurement that describes the thickness of the ozone layer in a column directly above the location being measured. For instance, if an ozone column of 300 Dobson Units is compressed to 0º C and 1 atmosphere (the pressure at the Earth’s surface) and spread out evenly over the area, it would form a slab of ozone approximately 3mm thick. Keep reading