The climate legacy of Justice Stevens

Retired Supreme Court Justice John Paul Stevens, who died yesterday at age 99, wrote the landmark 5-4 decision in 2007 that clearly gave EPA the power to regulate GHG emissions.

Why it matters: EPA began acting on that authority during the Obama years. Major rules include emissions standards for cars and power plants, which the Trump administration is weakening.

• Stevens also wrote the majority opinion in 1984's Chevron v. Natural Resources Defense Council, which gives agencies leeway to interpret statutes that are vague or silent on a topic. That’s important for regulators’ ability to craft rules on global warming.

Why you'll hear about this again: Democratic White House candidates are vowing to revive robust administrative steps, even as they float big legislative ideas that would face long odds in Congress.

What we're watching: How the expanded conservative majority on the Supreme Court will view the scope of EPA's power when another climate case arrives on its docket.

What they're saying: Several experts I asked about this last year said that while the conservative-led high court might narrowly view EPA's power under the Clean Air Act, it's unlikely to upend the 2007 decision Stevens wrote in Massachusetts v. EPA.