True to form, Mayor Bill de Blasio is taking credit for leading a global effort to divest from Big Carbon when he hasn’t even gotten the drive off the ground here in New York.

Before jetting (!) off to the Global Climate Action Summit in San Francisco, de Blasio joined London Mayor Sadiq Khan in signing an op-ed urging cities worldwide to pull pension-fund assets from fossil-fuel businesses and take “bold action to tackle climate change.”

Yet the mayor is way ahead of himself in declaring that New York City’s “divestment is underway.” Fine, he’s proposed a $5 billion divestment, but he’s only gotten three of New York’s five pension boards to agree to study divestment.

And city Comptroller Scott Stringer says the next step is a Request for Proposal for potential divestment — meaning the city hasn’t even written the specs for the contract to consider if what de Blasio pretends he’s already doing is even practical.

So when the mayor told NY1’s Errol Louis that “we’re never going to invest in them again,” he was discussing a divestment that’s unlikely to happen before he leaves office.

For the record, state Comptroller Tom DiNapoli opposes similar divestment by the state pension fund, telling Politico, “We have to be concerned about the bottom line.”

All this follows a federal judge’s outright dismissal of de Blasio’s much-hyped climate-change lawsuit against the top five oil companies.

Bottom line: De Blasio’s daily caravan of SUVs to and from his gym in Brooklyn is the least of the ways he keeps putting his carbon footprint in his mouth.