As the U.S. and China — the world's top two polluting nations — turn to implementing new rules aimed at curbing climate change, the countries can look to the most populous U.S. state as an example of the costs and challenges of fighting global warming.
California already has imposed some of the world's toughest air quality standards as it moves aggressively to lower emissions.
The state's cap-and-trade program, launched nearly three years ago, offers one of the few real-world laboratories on how to reduce carbon emissions. The state has opted to impose extra costs on businesses that emit pollutants.
November 13, 2014
