A new federal rule to cut power plant pollution and carbon dioxide emissions promises to escalate a yearslong, highly partisan battle at the core of U.S. climate change policy. Our Issue Backgrounder lays out the shifting regulatory approaches from the administrations of George W. Bush to Joe Biden, and notes the legal tug-of-war that has heightened the importance of another big player — the Supreme Court.

Plans for two new U.S. facilities that will use hydrogen instead of coal to make steel hold the promise of decarbonizing this essential but dirty industry. But don’t expect overnight change. Reporter Maria Gallucci looks at the complexities of making the switch, from ditching the ​blast furnace to reducing pollution all along the supply chain.

A massive data set that tracks greenhouse gas emissions in the United States is now newly updated, and the latest Reporter’s Toolbox calls it essential for informed reporting on U.S. climate policy. Its three decades-plus of measurements can help journalists track big emitters near them and from a variety of major sources ranging from landfill methane to industrial polluters.