global warming market: On Monday, President Obama is expected to announce a plan to cut carbon emissions from power plants by up to 30 percent with the help of state cap-and-trade programs. Cap and trade is one of the primary responses to global warming. It requires industries to have marketable permits to emit greenhouse gases. Reducing the permits would increase their price, lower emissions and stimulate innovation. Many say it has not worked out so well. Is cap and trade the best chance for stemming climate change,...