[Chicago Tribune] This environmentally conscious city is already home to the headquarters of the Whole Foods organic grocery store chain, a new City Hall built mostly with recycled materials and a municipal electric utility that features solar cells on the roof of its parking lot. The Texas capital also pays residents rebates if they install extra attic insulation or high-efficiency clothes washers. There are steep discounts on rainwater collection barrels. Low-flow toilets are practically free. But those are just eco-baby steps compared with Austin’s latest, and most ambitious, environmental quest: to lead the nation in slashing emissions of greenhouse gases that contribute to global warming.