Global warming

The 1991 eruption of Mount Pinatubo in the Philippines blanketed the Earth with a haze of sulfur dioxide that temporarily cooled global temperatures by one degree Fahrenheit. Some scientists now see the intentional injection of sulfur dioxide into the stratosphere as a potentially cheap and easy way to counteract global warming. Others warn, however, of potentially deadly unintended consequences.

A hotly debated study by Cornell University Professor Robert Howarth concludes that hydraulic fracturing for natural gas is as bad as coal mining--and perhaps worse--from a global warming perspective. Howarth says vast amounts of methane--a potent greenhouse gas--escapes during gas drilling and transportation, and this means that natural gas is not a clean, green bridge fuel to a low-carbon future. The industry strongly disagrees.

 Power Ahead, Midday's special look at energy problems and solutions continues. The focus this hour is global warming. Our guests include Mark Hertsgaard, author of HOT: Living Through The Next Fifty Years On Earth, Darren Samuelsohn, Politico senior energy and environment reporter and Kate Sheppard, Mother Jones energy and environmental politics reporter.