Last August, torrential downpours and flooding damaged some 55,000 homes in Louisiana. Thirteen people died, while the governor estimated the material damage to be $9 billion dollars. It was one of 15 natural disasters in the United States in 2016 that cost more than a $1 billion. Climate scientists expect floods like the one in Louisiana to occur 40 percent more frequently now than in pre-industrial times, because of climate change.

But an executive order that President Trump signed Tuesday afternoon may make it harder for communities on the front lines of climate change to prepare for and respond to the heightened risk of extreme weather events. Trump’s order (dubbed “Promoting Energy Independence and Economic Growth”) directs various agencies to begin the work of dismantling a slew of Obama-era policies related to energy and climate change—including the Clean Power Plan, designed to curb greenhouse gas emissions from power plants; limits on methane emitted by oil and gas operations; and a moratorium on the troubled federal coal leasing program. Speaking at a press conference, Trump described the directive broadly as an effort to “cancel job killing regulations” and unleash energy production.

The order also rescinds two Obama administration directives that serve as the backbone of the government’s climate adaptation work. Those orders did not impose new regulations on industry; instead, they were based on the idea that it makes good fiscal sense and is morally imperative to prepare for the effects of global warming, even while trying to limit it. One of the orders rolled back by Trump was issued in 2013 after Hurricane Sandy tore up the east coast, leaving in its wake $60 billion in damages. That order requires federal agencies to identify how climate change will affect their mission and programs, and to work with states and local communities to help them prepare.

It “was designed to address what we’re seeing now—extended droughts, extreme flooding, rapid sea level rise, deadly heat waves,” said Alice Hill, who served as the senior director for resilience policy on the National Security Council under President Obama. It was intended to protect federal assets—for instance, to make sure that buildings built with taxpayer money weren’t sited in areas facing heightened flood risk—and to protect local communities, by boosting their capacity and sharing information. “The president recognized that state, local, and tribal leaders bear the brunt of dealing with these impacts. These impacts are accelerating, and the Obama administration wanted to organize our federal efforts so that we were in a position to more effectively support people on the ground,” Hill explained.

The other order rescinded by Trump directed the Department of Defense and other agencies to consider climate change impacts when developing national security plans. Among other things, that meant preparing military bases for rising sea levels, leveraging renewable energy, and studying the security risks posed by changing weather patterns with the potential to destabilize foreign governments and heighten cross-border conflicts. For example, the Syrian civil war has been linked to an extreme drought that researchers believe was likely due to climate change.

“To repeal this executive order which requires agencies to incorporate consideration of climate risks in national security planning seems very short sighted, and really puts the nation at risk,” said Hill, noting that every defense secretary since George W. Bush appointee Robert Gates, including Trump appointee James Mattis, has acknowledged that climate change poses a national security threat.

In theory, adaptation and resiliency programs should be uncontroversial: Even if you don’t accept that humans are to blame for rising global temperatures, it still makes sense to make communities more resilient to extreme weather events. “I think it’s prudent to, say, avoid construction in floodplains, particularly if the number of floods in that area is likely to increase and sea level is rising. That’s risk mitigation that just makes sense from a Department of Defense perspective—it’s selfish, rather than selfless,” said John Conger, who served at DOD as principal deputy under secretary, and as assistant secretary of defense for energy, installations and environment. Conger is concerned that rescinding the memorandum will have a “dampening effect” on the military’s preparedness work. But he pointed out that Defense Department can still factor climate change into its work even without a mandate from Trump.

While Trump’s order may make the country more vulnerable to natural disasters, it’s also bad for business. According to a recent article in Wired, the “Adaptation Economy” amounts to about $280 billion each year worldwide. It spurs infrastructure spending and creates jobs, two things Trump said he wants to prioritize. And it would make natural disasters less costly. But the Trump administration seems not to care much about the economic consequences of rising sea levels and other changes. “I’m not familiar with what you’re talking about,” a senior White House official told a reporter on a conference call Tuesday when asked about it. “I would want to see the research.”

Susan Ruffo, who was the associate director for climate preparedness at the White House Council on Environmental Quality under Obama, said the damage done by deemphasizing adaptation will be felt most acutely by small, environmentally-vulnerable towns like Perdido Beach, in coastal Alabama. “The biggest effect is that we’re no longer going to have a federal government that’s really supporting these local leaders, and it’s really going to affect the people who don’t have a lot of capacity on their own,” Ruffo said. “Climate change touches so many thing that people don’t think about, whether it’s the expansion of lyme disease in the Northeast or the fact that Salt Lake City now has three weeks less of water storage because their snowpack is melting earlier…. It’s those very real impacts that are going to continue.”