Ignoring inaction at the highest levels of the U.S. government, 145 mayors across the country have formed a coalition to combat global warming and begun to reshape their cities using innovative programmes and technologies. The mayors say they can make urban living more eco-friendly and at the same time create jobs and stimulate local economies. The Kyoto Protocol, an international treaty calling for reductions in the greenhouse gases that accelerate climate change, took effect in February. But the United States, which makes up four percent of the world's population and produces 22 percent of the world's greenhouse gases, did not ratify the treaty.