Dozens of military installations around the country already are experiencing the impacts of climate change, and rising seas, wildfires and other climate-fueled disasters are likely to cause increasing problems for the armed forces, the Defense Department said Thursday in a report to lawmakers on Capitol Hill.

The 22-page document comes in response to a request from Congress in an annual funding bill, which required defense officials to provide a list of the 10 most vulnerable sites that each military branch faces over the next two decades, and an analysis of what could be done to protect them.

The document affirms a longstanding sense that the U.S. military, with massive energy needs and bases flung around the globe – including some on low-lying islands -- is well attuned to how the planet is changing due to the burning of fossil fuels.

But while the report calls climate change “a national security issue” and highlights individual bases that face potential impacts, it did not include such a list of the most at-risk installations -- an omission that drew quick criticism on Friday.

“It seems like they have not made it past anecdote to analysis,” said John Conger, director of the Center for Climate and Security and former acting assistant secretary of defense for energy, installations and the environment. “It’s concerning to me because Congress was looking for the department’s best judgment on how to prioritize the risks.”

Department of Defense spokeswoman Heather Babb said Friday that the report “represents a high-level assessment” of the vulnerabilities that military installations face from floods, droughts, wildfires and other climate- and weather-related threats, as well as an overview of efforts to increase resiliency.

"DoD will focus on ensuring it remains ready and able to adapt to a wide variety of threats - regardless of the source - to fulfill our mission to deter war and ensure our nation’s security,” Babb said.

Examining 79 military installations, the report finds that 53 already suffer from “recurrent flooding,” 43 have been exposed to drought, and 36 to risk from wildfires. And it finds that risks like these could extend to more installations in the coming years.

Rhode Island Democratic Senator Jack Reed, ranking member of the Armed Service Committee, blasted the document, charging that the Defense Department failed to answer the key questions that lawmakers were seeking, and instead produced an “alphabetical” list of selected installations facing climate risks.

“While those 79 installations are no doubt important for mission assurance, without any prioritization for resources and installation-specific resilience plans, the report is incomplete,” Reed said in a statement on Friday. "Instead, the report reads like a introductory primer and carries about as much value as a phone book.”

Congressman Jim Langevin (D-R.I.), a member of the House Armed Service Committee, sponsored the amendment to the defense spending bill in late 2017 that required the report. He said Friday he was deeply disappointed.

"While the Pentagon does rightly acknowledge that a changing climate will affect military readiness and installations, the report does not reflect the urgency of the challenge,” Langevin said in a statement, noting that recent hurricanes caused billions of dollars in damage to Tyndall Air Force Base in Florida and Camp Lejeune in North Carolina.

But the Pentagon’s Babb countered that “the report highlights the climate vulnerabilities of the top 79 mission assurance priority installations. By using this alternative approach, we are able to highlight where there are operational risks.”

This week’s report differs from another study backed by the military and published last year, which showed that more than a thousand low-lying tropical islands risk becoming “uninhabitable” in coming decades, upending the population of some island nations and endangering key U.S. defense assets.

The research has ramifications for the U.S. military, whose massive Ronald Reagan Ballistic Missile Defense Test Site sits, in part, on the atoll island of Roi-Namur — a part of the Marshall Islands and the focus of the research. The U.S. military supported the research in part to learn about the vulnerability of its tropical-island installations. The Pentagon base on Roi-Namur and surrounding islands supports about 1,250 American civilians, contractors and military personnel.

Last year the Pentagon also released a survey of a much larger number of military installations and the risks they were facing, but that document appeared to have been watered down somewhat in comparison with a draft version composed during the Obama administration.

By contrast, this week’s report only examined a smaller subset of installations, their current risks, and whether those are expected to increase over the next 20 years.

The document does point out that individual bases are experiencing serious problems -- for instance, from flooding and wildfires.

“Joint Base Langley-Eustis (JBLE-Langley AFB), Virginia, has experienced 14 inches in sea level rise since 1930 due to localized land subsidence and sea level rise,” the document notes. “Flooding at JBLELangley, with a mean sea level elevation of three feet, has become more frequent and severe.”

Meanwhile, Vandenberg Air Force Base in California saw 380 acres burned in a wildfire last year and required evacuations, the report said.

On a global scale, climate change can make the military’s job harder by creating regional instabilities through worsening disasters, the report said. And it notes that with more maritime activity in the melting Arctic, the Navy’s job is getting tougher.

And, the document notes, since it only looks out 20 years, military installations could face far greater challenges beyond that timeframe.

“Analyses to mid- and late-century would likely reveal an uptick in vulnerabilities (if adaptation strategies are not implemented),” the report noted.