Chicago Unveils Multifaceted Plan to Curb Emissions of Heat-Trapping Gases CHICAGO - Mayor Richard M. Daley of Chicago on Thursday unveiled perhaps the most aggressive plan of any major American city to reduce heat-trapping gases. The blueprint would change the city's building codes to promote energy efficiency. It also calls for installing huge solar panels at municipal properties and building alternative fueling stations. Ron Burke, a director with the Union of Concerned Scientists, which helped shape the plan, said it was "more robust and quantitative than those in any other city." Like hundreds of other cities, Chicago has pledged by 2020 to reduce the emissions of heat-trapping gases 25 percent from the levels in 1990, the baseline established by the Kyoto Protocol, an international climate treaty. Mr. Burke said the Chicago plan offered much more specific ways than other cities" plans to measure and cut the emissions. The mayor, who called the plan a "model for the rest of the nation," has already won praise among environmentalists for a program that promotes rooftop gardens to conserve energy. The city plan, which draws on the work of climatologists, warns that the failure to act will produce dire consequences. "People think in terms of polar ice caps and rising ocean levels," Mr. Burke said, "but this takes a look at what would happen to a Midwestern city like Chicago if nothing is done." By the end of the century, if no action is taken, he said, Chicago is likely to face 30 more days of 100-degree weather per year, as well as stretches of severe drought. "The climate of Chicago," Mr. Burke said, "would resemble what is currently East Texas." This was the first time a major American city has produced models to show local effects of global warming, he added. Sadhu Johnston, the chief environmental officer for the city, said that perhaps the most ambitious part of the plan was retrofitting low-cost housing complexes to reduce water and energy use. But getting the cooperation of the private sector for some of the more costly initiatives may be difficult. "Make no mistake," Mr. Johnston said, "we're facing huge challenges, especially with the credit crunch." The Chicago initiative included consultation with business and labor leaders, as well as scientists and environmentalists, and involved 18 months of research and discussion. Mr. Johnston said the initiative came "despite the lack of federal support." Some of the changes in the building codes will require approval of the City Council, but that is considered virtually guaranteed, given Mr. Daley's political power. The plan will also publicize ways that people can reduce their carbon imprints. Mr. Johnston said popular sentiment for conservation was so strong these days, especially with high fuel costs, that people were eager to find ways to cut emissions. "We don't need mandates," he said, "so much as we need to give people the tools that allow them to green their own lives." As part of the outreach, the program will issue what it calls "the $800 challenge," giving tips for everyday life that could cut energy expenses by that amount for the average resident. "We're going to try to get office buildings to compete against one another," Mr. Johnston said, to see who can reduce energy levels the most. Some parts of the initiative have already been put into effect. Over the past two years, the city and its partners have distributed more than one million energy-saving compact fluorescent light bulbs. "We can't solve the world's climate change problem in Chicago," Mr. Daley said at a news conference at the John G. Shedd Aquarium, "but we can do our part."