Tennessean: For those deeply concerned about climate change, the new EPA rules limiting CO2 emissions from existing power plants are a welcome first step. However, there is room for improvement in the draft rules before they become final in June 2015. The biggest flaw is that they dont explicitly name a carbon tax as a mechanism states could use to comply. Among economists, a carbon tax is widely accepted as the most economically efficient and cost-effective way to reduce CO2 emissions. Detractors who argue...