New York city, a collection of islands with 578 miles of coastline, is taking a big step in preparing for climate change. Last month, the Mayor’s Office of Recovery & Resiliency (ORR) released preliminary Climate Resiliency Design Guidelines for all of the city government’s capital projects, from libraries to bridges. The recommendations will now enter a pilot phase before being finalized in December.

While President Trump has denied climate science and is removing many of his predecessor’s climate-focused environmental regulations, highly vulnerable cities such as New York cannot afford to be unprepared. As Superstorm Sandy demonstrated in 2012, the population and economic activity threatened by more frequent extreme weather events is enormous. The new design guidelines are just one of ORR’s efforts to fortify New York against climate change. It also is surrounding Lower Manhattan with parks that serve as flood barriers and constructing a series of protective breakwaters along the coast of Staten Island.

Building regulations have relied on historical data for temperatures or storm surges, but now New York will look ahead to future projections across four areas of climate risk: storm level surges, sea-level rise, higher temperatures, and escalating peak precipitation.

Those risks over the expected lifetime of new buildings, roads, parks, and other public infrastructure projects are significant. For example, according to the New York City Panel on Climate Change (NPCC)—an independent body of scientists formed in 2008 by then- Mayor Michael Bloomberg—by 2050, New York’s average temperature is projected to increase between 4.1 and 6.6 degrees Fahrenheit. Last year, an article in the journal Environmental Health Perspectives found annual heat-related deaths in New York could increase by more than 500 percent by the 2080s.

But while the guidelines recommend features such as green roofs and lighter-colored, reflective surfaces to mitigate the urban heat island effect, they will not require any specific measures. “We’re not being prescriptive about the strategy,” says Susanne DesRoches, deputy director of infrastructure policy for ORR. “We want the design community to come back to us and say, This is how you can incorporate this climate data and resiliency.”

The city is taking the same open-ended approach to preparing for other threats. For dealing with heavier storms—New York’s rainfall is expected to increase by 4 to 13 percent by midcentury—the city will lay down permeable streets and build bioswales. But how exactly, say, a landscape architect might bring that information to bear on a new pocket park will be proposed by the designers and decided by the relevant agency on a case-by-case basis.

DesRoches and her colleagues worked closely with the city agencies responsible for actually building new projects, such as the Department of Parks and the Department of Environmental Protection, and they consulted the climatechange and resilience strategies already being employed in other coastal cities such as Boston and Miami. They also leveraged data produced by the NPCC’s biannual reports that attempt to measure how the likely global average temperature increases and related effects will be manifested in New York. ORR used those local projections to draft the guidelines.

DesRoches says that, with these recommendations— which go beyond the building code required of private developments—“the city is really going to lead by example.” The hope is that the private sector and other cities will follow suit. Climate change, and our understanding of it, is constantly evolving and so too must architecture and engineering. Says DesRoches, “This is what we see as a first step.”