More than 80,000 homes on Staten Island and in southeast Queens and the suburbs east of New York City could be lost to floods over the next 15 years, according to a new report that serves as a warning of how climate change could make the housing crisis even worse.

The report, released Monday by the Regional Plan Association, a nonprofit civic organization, said that swaths of land in every borough were likely to become impossible to develop, helping push the area’s housing shortage to a staggering 1.2 million homes.

“You’re going to need to build more housing to just replace what is lost in your own municipality,” said Moses Gates, the association’s vice president for housing and neighborhood planning and an author of the report.

The report is the latest to underscore how the dual threats of climate change and a lack of housing are looming over coastal cities around the world.

New York City and its suburbs have not built enough homes to meet demand over the past few decades, helping to drive up rents and home prices. At the same time, the metropolitan area is struggling to adapt to increased flooding and other extreme weather caused by global warming.

“The sooner we decide as a city to invest in resilience measures to help neighborhoods adapt — whether it’s to fortify or to move — the faster we avert leaving an even bigger crisis for the next generation,” said Amy Chester, the managing director of Rebuild by Design, a nonprofit that works to make infrastructure better able to withstand storms and climate change.

The report did not single out specific neighborhoods as at risk for flooding. But of the 82,000 homes that could be lost by 2040, more than half were projected to be on Long Island, with some Atlantic Ocean-facing towns like Babylon and Islip bearing the brunt.

Cities along the Long Island Sound on both the island and in Westchester County would also be vulnerable. In New York City, waterfront neighborhoods in southern Queens and Brooklyn, like the Rockaways and Canarsie, would see the most losses.

Some new developments on the Rockaway Peninsula in Queens, where about 125,000 people live, are focused on trying to protect against flooding while also providing dense, affordable housing.

Also in the Rockaways, a new system of engineered berms, which look like sand dunes but have stone and steel walls at their cores, will help protect the ocean side of the peninsula. But little progress has been made on the bay side, which floods regularly.

Throughout the city, other mitigation measures are underway or already complete, including flood walls and floodgates on the Lower East Side of Manhattan, and nature-based solutions, like bluebelts, which connect storm sewers to lakes and ponds.

After Superstorm Sandy inundated much of Staten Island’s eastern shore in 2012, the state bought more than 500 damaged homes, clearing most of them to return the land to a natural state in a practice known as managed retreat. But a costly, ambitious plan to protect the entire city from coastal storms has yet to be approved by the federal government and is at least 20 years away from completion.

The threats of global warming mean that local officials need to “rethink what a conventional home looks like,” said Max Besbris, a sociology professor at the University of Wisconsin-Madison who specializes in housing and climate change.

“That means denser housing, more energy-efficient housing, and that probably means giving up on that suburban ideal of a stand-alone home with a white picket fence,” he said.

The report from the Regional Plan Association analyzed the amount of housing the area needed today and in the future to make sure there were enough homes available for people to easily move into. The report said the region needed 362,000 additional homes today, in part to relieve overcrowding and permanently house the shelter population, among other factors.

In 15 years, that number will more than triple to 1.2 million, when accounting for population growth, flood loss and general housing deterioration. Cities and towns should cluster growth in the parts of the region that have a relatively lower risk of flooding and are near public transit and commercial hubs, the report said.

Warren Schreiber, the president of the Queens Civic Congress, a group of civic associations from across the borough, said he agreed that people needed to be made safe from flood risks. But he said that any new development should focus on affordable housing, which raised the question of how much that development would cost.

“Who’s going to pay for this?” he said. “Is it going to be on the backs of middle-income working-class families?”

The report also used a tool called the National Zoning Atlas, which maps local restrictions on development to see where the zoning codes might allow for more homes to be built. The report found that 580,000 homes — less than half of what is needed — could be added under today’s zoning codes (though other factors, like funding or building codes, might also prevent homes from being built).

That housing gap showed the need for nearly every city, town and village to change their zoning codes to allow for more homes to be built, said Mr. Gates, one of the report’s authors.

New York officials have tried to adapt zoning codes for easier building in recent years, with mixed success.

Gov. Kathy Hochul tried to push every city and town in the state to make way for more housing two years ago. But local leaders in the city’s suburbs, especially on Long Island and in Westchester County, resisted her efforts.

The administration of Mayor Eric Adams successfully pushed a plan known as “City of Yes” that could allow for some 80,000 additional homes to be built over the next decade. That plan, which the City Council approved in December, would reduce the city’s housing needs by only 11 percent, the report found.