On Monday, President Obama launched his Clean Power Plan designed to cut emissions from the power sector by 32% in 2030, against a 2005 baseline.
It's more ambitious than a draft, published for comment last year, which targeted a 30% reduction. Obama says it is the "single most important step" the US has taken to tackle climate change.
It has attracted a huge quantity of news coverage, comment and analysis. However, the final rule is 1,560 pages long, making it hard to unpick the impact of the plan from the spin. It also has international significance in advance of the impending UN climate talks in Paris.
Carbon Brief's Q&A aims to help cut through the noise, explaining the why, how and what next of the Clean Power Plan.
For the complete analysis, please visit the Carbon Brief Blog.