About half of U.S. military facilities around the world have experienced climate extremes and threatening weather, according to a new Pentagon survey obtained and published Monday by a climate security think tank.

The survey, which was the first of its kind and was shared with Congress, said about half of the 3,500 sites it contacted reported effects from six key categories of extreme weather, such as storm surge, wildfires and droughts. The study was requested by Congress in 2015 and completed this month.

The nonpartisan Center for Climate and Security posted the full report on its website Monday. It provides a wealth of data and begins to paint a preliminary “picture of assets currently affected by severe weather events … as well as an indication of assets that may be affected by sea level rise in the future.” The report on the survey was conducted by the Pentagon’s undersecretary of defense for acquisition, technology and logistics.

The results do not point to specific effects of climate change but do identify particular bases where extreme weather is already reported as a problem, said John Conger, a senior policy adviser with the Center for Climate and Security who helped kick off the survey effort during his time as an assistant secretary of defense.

“If there are increases in climate change, this sort of points them in the right direction,” Conger said.

The Pentagon could also use the data as it compiles a new study for Congress on its 10 facilities most vulnerable to climate change, along with plans and costs of protecting them, he said.

Lawmakers added the requirement to the National Defense Authorization Act, the massive annual policy bill passed in December. The NDAA, which was written and passed by a Republican-controlled Congress, also identifies climate change as a direct threat to national security.

The survey and the NDAA requirement are at odds with President Trump’s recently released national security strategy, which dropped references to climate change used throughout the previous strategy by the Obama administration in exchange for a focus on energy independence and American business.

More than 780 military sites reported drought conditions, which was the most common climate extreme, followed closely by wind and flooding, according to the survey report.

Storm surge, which is often associated with climate change, hit 225 sites, and wildfires were reported at 210.

“The effects of climate and extreme weather represent additional risks to incorporate into the department’s various planning and risk management processes,” according to the report.