A lot has happened since we were last in your inbox.

On Sunday, President Biden dropped out of the presidential race, clearing the way for Vice President Kamala Harris to take his place, and it’s now highly likely that she will be running against former President Donald J. Trump in November.

Harris, as Lisa Friedman wrote, “has for years made the environment a top concern,” and earlier in her career took positions far to the left of Biden on climate change. She prosecuted polluters during her time as California’s attorney general, was an original co-sponsor of the Green New Deal as a senator and cast the tiebreaker that led to the passage in 2022 of the Inflation Reduction Act, the largest climate investment in U.S. history.

This is partly why Harris is widely expected to continue the work Biden started if she is elected.

We have a hint about what that could look like. Harris’s climate adviser, Ike Irby, told Friedman that the vice president would focus on implementation of the I.R.A. if elected.

That may sound underwhelming, but experts told me it’s actually a pretty big challenge and key to hitting the U.S.’s climate goals.

Making it count

Ensuring that the hundreds of billions of dollars for clean energy in the I.R.A. and the bipartisan infrastructure law signed in 2021 actually translate into lower emissions is easier said than done.

Brad Plumer, who has been covering this process, told me that the I.R.A. could end up helping to cut America’s greenhouse gas emissions either a lot or just a modest amount, depending on how the law is implemented.