WASHINGTON -- President Donald Trump's decision to withdraw the U.S. from the Paris climate agreement puts him at odds with the Pentagon, which has been warning for years that climate change poses a critical national security threat.
At his confirmation hearing, Defense Secretary Jim Mattis called climate change a "driver of instability" that "requires a broader, whole-of-government response."
For more than a decade, military leaders have said that extreme weather patterns and rising sea levels are aggravating social tensions, destabilizing regions and feeding the rise of extremist groups such as al-Qaida and the Islamic State.
Closer to home, scientists estimate that rising sea levels threaten at least 128 U.S. military bases, some of which are already flooding.
"The nature and pace of climate changes being observed today ... are grave and pose equally grave implications for our national security," says a 2007 report by the Military Advisory Board, an elite group of retired three- and four-star flag and general officers from the Army, Navy, Air Force, and Marine Corps. "It is important that the U.S. military begin planning to address these potentially devastating effects."
In 2014, the Pentagon released a Climate Change Adaptation Roadmap that declared "climate change will affect the Department of Defense's ability to defend the nation and poses immediate risks to U.S. national security." Another Pentagon report in 2015 called climate change a "threat multiplier."
As politicians have squabbled over what actually causes climate change, or whether China or India should be doing more, the Pentagon has been trying to map out a long-term strategy to mitigate the risks that it not only sees on the horizon, but is already experiencing.
"Climate change is already impacting the military itself, how it operates, and the countries in which we have an interest where it can result in instability, which leads to violence, which leads to conflict and where we end up moving our young men and women overseas," said retired U.S. Army Brig. Gen. Gerald Galloway, who is now a University of Maryland engineering professor.
U.S. military operations, personnel and installations are already being affected by the increased risk of instability overseas as a result of climate change, and dealing with it will require international cooperation, he said.
Trump's decision, which he dramatically announced in the White House Rose Garden, will have "an immediate effect" on the relationship with U.S. allies, Galloway said.
"We need our allies to be dealing with this the same way we are, so the concern is that pulling out of the existing treaty sends a message that we don't really care about the issue," he said. "Mattis has already said, 'I am going to be worried about this,' but it's the concern that [Trump's announcement] will be taken as the definitive statement."
It was a concern echoed on Wednesday by Secretary-General of the United Nations Antonio Guterres.
He warned the U.S. that "if one country decides to leave a void, I can guarantee someone else will occupy it." The only other countries not in the accord are Syria and Nicaragua.
"Around the world, military strategists view climate change as a threat to global peace and security," he said in a speech at New York University. "We are all aware of the political turmoil and societal tensions that have been generated by the mass movement of refugees."
On a more basic level, extreme weather patterns and rising sea levels are already having an effect on U.S. military facilities.
Naval Base Ventura County in southern California has lost about 400 feet of beach since the 1940s. The sea level at Naval Station Norfolk in Virginia has risen 14.5 inches in the century since World War I, when the facility was built.
Military installations on waterfront properties are facing hundreds of floods a year, and in some cases could be mostly submerged by 2100, according to a report from the Union of Concerned Scientists. The report calculated that a three-foot sea level rise would threaten at least 128 U.S. military bases, which are valued at $100 billion. Nine of those are major hubs for the U.S. Navy.
Earlier this month, a group of 17 retired military officers sent letters to Mattis and Secretary of State Rex Tillerson urging them to remain firm in their commitment to combat climate change as the White House weighed leaving the accord.
"Climate change poses strategically significant risks to U.S. national security, directly impacting our critical infrastructure and increasing the likelihood of humanitarian disasters, state failure and conflict," they wrote.
This article is written by Vera Bergengruen from Special to McClatchy Washington Bureau and was legally licensed via the Tribune Content Agency through the NewsCred publisher network. Please direct all licensing questions to firstname.lastname@example.org.