BURLINGTON -- In a tour intended to raise awareness about global warming, a 20-foot tall, inflated model of the Earth, adorned with painted flames, stopped in Burlington last Thursday morning. Shoppers at City Market were greeted by the generator-powered balloon, which will travel by car to 28 states this summer, courtesy of the Vermont Public Interest Research Group. Representatives from VPIRG and the offices of Sens. Patrick Leahy and Jim Jeffords held a joint press conference next to the Earth, calling for an 80 percent reduction in global-warming pollution by 2050. Last year was the hottest year on record, and increased temperatures threaten Vermont's ski and maple sugar industry, and its overall economy, the speakers said. According to VPIRG campaign coordinator Hannah Polow, the U.S. has the technology to reduce its dependence on oil, reduce air pollution, and protect pristine landscapes from oil drilling and mining. She did not say how much fossil fuel will be used to haul the deflated globe around the country.