Yabba-dabba-don’t.

Mayor Bill de Blasio is preparing to take New York City back to the stone age — by making “glass and steel” skyscrapers extinct.

Still flirting with a run for president, the mayor held an Earth Day press conference on Monday to announce his plan to fight climate change with a “Green New Deal” — including a bill designed to eliminate new glass-fronted towers from the city skyline.

“We are going to introduce legislation to ban the classic glass and steel skyscrapers that have contributed so much to global warming,” de Blasio said.

“They have no place in our city or our Earth anymore.”

Despite Hizzoner’s insistence on repeatedly using the word “ban,” he later admitted his legislation would actually just tighten the city’s energy code to make it prohibitively expensive to develop glassy high-rises.

“It’s literally going to be a much higher standard and the only way that kind of design would even be acceptable is with a whole host of other changes were made to compensate because those buildings were inherently very inefficient,” he said.

Mark Chambers, director of Mayor’s Office of Sustainability, was forced to clarify that “it doesn’t mean buildings can’t use glass anymore.”

He pointed to the recently erected American Copper Building in Murray Hill — a K-shaped structure clad in copper and glass — as an example of a structure that would still be ­acceptable.

De Blasio cited unspecified buildings in the Hudson Yards development as “examples of the wrong way to do things.”

Hudson Yards developer Related later hit back by pointing out that it has just opened a glass office building that is certified LEED platinum — the US Green Building Council’s highest designation — and is “one of New York’s most energy-efficient Class A office towers.”

The mayor’s Green New Deal — a title borrowed from freshman Rep. Alexandria Ocasio-Cortez’s vague and pricey plan to cut carbon emissions — will hold builders to such sky-high standards that even developers who’ve focused on staying eco-friendly will be punished.

Last week, the City Council passed a bill to slap strict greenhouse emissions caps on private buildings exceeding 25,000 square feet by forcing them to retrofit pipes, heating systems, lights and other utilities by 2024 or face big fines.

The Bank of America Tower on 42nd Street, for example, is certified LEED platinum, but developer the Durst Organization calculated that it would still face $2.5 million in fines under the new bill when 2024 rolls around.

“The fine will escalate annually from there,” chief development officer Alexander Durst told Crain’s.

Critics say the new measures are unrealistic — there likely aren’t even enough contractors to get all 50,000 affected buildings up to code in time, and the pie-in-the-sky targets will just turn businesses away from the Big Apple.

Meanwhile, smaller buildings, hospitals, NYCHA housing complexes, and “affordable” housing won’t be subject to the same rules.

“The caps that they are expected to meet are unrealistic,” said Carl Hum, general counsel for the Real Estate Board of New York, said of office towers.

“The law doesn’t taken into account what the building does. Tech and media are energy intensive. You’re going to have an owner who will think twice on who they rent out to avoid fines.”

Hum said the glass and steel “ban” announcement had blindsided the ­industry.

One expert said she expected “pushback” because glassy buildings are all the rage among designers and a hit with customers.

“I think architects are in love with the uniform skin,” said Hillary Brown, a professor at the City College of New York’s School of Architecture.

“It’s just been a trend for so long and I think we need to use architectural imagination in considering other building enclosure treatments.”

De Blasio said he doesn’t care what one of the most important industries in the city thinks.

“We certainly felt the opposition at the real estate lobby in these last months, but to the credit of everyone here, we said we don’t care how much opposition there is,” he said.

The mayor’s goal is to reduce emissions by 40 percent by 2030.

Among other elements of Hizzoner’s eco-friendly scheme, the mayor plans to make his struggling composting program mandatory — even though he put it on hold last year because residents weren’t ­participating.

De Blasio said he plans to pass bills for the glass and steel building “ban” and forced composting program this year — while admitting he doesn’t have a timeline for the rollout of the latter because it will take “a lot of public education.”