The chief executive officer of BP Plc had ­something ­exciting to tell investors in September 2019. The fifth-­largest multinational oil producer in the West had just inked a deal to sell everything it owned in Alaska, marking a sudden exit from a region the company had prized since the birth of the state 60 years earlier. The $5.6 billion sale would help reduce corporate debt, but that wasn’t the only boon. BP would be proudly shedding unwanted greenhouse gases, paving the way toward what would soon become its signature goal: zeroing out emissions by midcentury.

“There are going to be projects that we don’t do, things that we might have done in the past—certain kinds of oil, for example, that have a different carbon footprint,” then-CEO Bob Dudley said on the conference call. The divestiture would help the British supermajor meet its climate targets while it gradually reinvented itself as a clean energy leader backed by sustainability-minded investors. It’s one of two recent moves that allows BP to wipe at least a sixth of its 2019 emissions from future reports, alongside a third divestment that lets the company avoid claiming potential future emissions.