Recently, the state of Washington embarked on an ambitious new plan to combat climate change. Taking a page from economics textbooks, the state instituted a statewide "cap and trade" system for carbon emissions. The state establishes a cap on the total amount of carbon pollution it is willing to allow each year, and then gives away or auctions off carbon emission permits that add up to that total. Companies can then trade those permits on the open market. Economists love cap and trade plans because they establish a limit on carbon emissions while letting the market find the most efficient way for decarbonization to occur. But cap and trade has had a hard time catching on, especially in the U.S. The stakes are high for Washington's new plan. If it succeeds, it could convince other states to implement their own versions, but if it fails, it might serve as a cautionary tale. On today's show, we take a look at how Washington's grand experiment with cap and trade is faring. This episode was hosted by Keith Romer and Kenny Malone. It was produced by Emma Peaslee and edited by Emily Siner. It was fact checked by Sierra Juarez and engineered by Valentina Rodriguez Sanchez. Alex Goldmark is Planet Money's executive producer. Help support Planet Money and hear our bonus episodes by subscribing to Planet Money+ in Apple Podcasts or at plus.npr.org/planetmoney. Learn more about sponsor message choices: podcastchoices.com/adchoices NPR Privacy Policy