NEW YORK—Mayor Michael Bloomberg kicked off the World Science Festival—a collection of events, workshops and performances to celebrate science's effect on the world—here today by slamming policymakers for putting politics before science.

He cited instances where politicians ignored scientists' early warnings about potentially catastrophic issues, such as the first reported link between smoking cigarettes and lung cancer in the 1950s and predictions about increased atmospheric greenhouse gases.

There is a "tragic lag between what we know and what we do," Bloomberg said during his speech delivered at Columbia University. "Far too often, it's because of what I call 'political science'—the willingness to disregard or suppress scientific findings when they don't conform to a predetermined political agenda. Today we're seeing the tragic economic and environmental consequences of such political science writ large in our nation's misguided policies concerning two of the world's fundamental needs: food and fuel."

Bloomberg denounced federal government set-asides for farmers who produce corn-based ethanol, a biofuel that recent research showed may exacerbate rather than reduce climate change by emitting more carbon dioxide during its production than it saves, while sucking up an important food source. He noted that the subsidies were adopted in lieu of a policy that held more promise of stemming global warming, including vehicle fuel-efficiency requirements, more funding for mass transit, and other, more efficient biofuels, such as sugarcane-based ethanol.

"When such political science triumphs, both politics and science suffer," he said. "So does our entire society."

He called for support of science, recalling that many of the nation's founding fathers were both pols and scientists (think: Ben Franklin and Thomas Jefferson). He added that we could restore that heritage by heeding scientific findings, a practice he has followed since becoming the Big Apple's mayor in 2002.

Shortly after taking office, Bloomberg fingered "tobacco as the leading cause of death in our city," blaming it for the deaths of some 10,000 New Yorkers annually. He proposed and signed into law legislation that bars smoking in public places (including restaurants and bars) and imposed a steep tax hike on cigarettes. The mayor estimates that since the law took effect later in 2002, the number of smokers in the city has dipped by 20 percent, including a 52 percent drop among teenagers, at least partially due to the huge tax increase.

"It sets an example for cities across the nation and countries around the world," Bloomberg said. He added that other nations have followed suit, including Italy, Norway, the U.K. and Turkey, which also instituted smoking bans in public areas to limit the effects of secondhand smoke.

But smoking is not the only health issue high on Bloomberg's agenda. He noted that Gotham has also taken a lead in tackling climate change. In 2006 the city measured the amount of greenhouse gases it emits (58 million metric tons of carbon dioxide produced per annum) and took steps designed to reduce them nearly 30 percent by 2030. Among the goals: by 2017, a 30 percent reduction in the city government's carbon footprint; by 2012, the complete conversion of the city's taxi fleet to hybrids (or the equivalent); and, by next year, doubling solar power usage.

"In addition to being a center of finance, entertainment, fashion and culture, New York is also a world leader in scientific research," said Bloomberg, a Johns Hopkins–trained engineer who was hailed a "great friend of science" by festival co-founder Brian Greene. "This World Science Festival will really put the spotlight on that."

The first annual World Science Festival, which is open to the public, has programs running from tomorrow through Sunday at different venues in the city. In addition to Bloomberg's keynote address, The Kavli Foundation, a promoter and supporter of scientific research, based in Oxnard, Calif., today presented its Kavli Prizes to seven scientists in astrophysics, neuroscience and nanotechnology. The multiple winners in each field will share the $1-million awards given for each category.