The Trump administration has failed to include climate change in their National Security Strategy, contradicting decades of military planning.
The strategy, which was released last month, abandoned any mention of the climate issues critical to national security, including conflict from extreme weather events and the danger of rising seas on coastal military facilities.
The decision has led to outrage and criticism from both sides of the aisle, leading a bipartisan group of lawmakers in the House of Representatives to write the President a letter.
The letter, written this week and signed by 106 lawmakers - including 11 Republicans - urges the President to reinstate climate change as a major security threat.
"Failing to recognize this threat in your National Security Strategy represents a significant step backwards on this issue and discredits those who deal in scientific fact," the letter argues.
The Trump administration's strategy, which only mentions 'climate change' once, stands in direct opposition to the Obama administration's 2015 version, which mentioned 'climate change' 13 times and had "Confront Climate Change" listed as a security priority.
"We have heard from scientists, military leaders, and civilian personnel who believe that climate change is indeed a direct threat to America's national security and to the stability of the world at large," write the authors of the letter, Representatives Jim Langevin and Elise Stefanik.
"As global temperatures become more volatile, sea levels rise, and landscapes change, our military installations and our communities are increasingly at risk of devastation. It is imperative that the United States address this growing geopolitical threat."
The letter points out that Trump's own Defense Secretary, James Mattis, told Congress he agreed "the effects of a changing climate… will impact our security situation" in his confirmation hearing.
The Trump administration's strategy also conflicts with Congress' 2018 National Defense Authorization Act (NDAA), which declared climate change "a direct threat to the national security of the United States," and which Trump himself signed into law in December.
The 2018 NDAA requires the Pentagon study the impact of climate change on the U.S. military and report the findings back to Congress.
Nevertheless, Deputy Defense Secretary Patrick Shanahan has said the Pentagon's defense strategy will not mention climate change.
"We don't specifically address climate change. ... There is only so much, you know, depth and breadth. ... It really reflects the high priorities of the department," Shanahan told reporters at the Pentagon.
Clearly, climate change is not one of those priorities.