Arizona Daily Star: The Tucson community has a clear stake in the national climate-change legislation now working its way through Congress. Though the Waxman-Markey bill is imperfect in several ways, it does deserve enactment for many reasons important to our community. Critics complain that the time frames for greenhouse-gas reductions in Waxman-Markey are too distant, that the emission reductions sought are inadequate, that the carbon-trading mechanisms are too unwieldy. Yet despite its flaws, …