On Tuesday, President Donald Trump—a long-standing denier of human kind's influence on climate change—signed the National Defense Authorization Act for Fiscal Year 2018 into law. The bill, however, not only acknowledges the existence of climate change but requires a report to be submitted within one year to the Committees on Armed Services of the Senate and the House of Representatives detailing the "vulnerabilities to military installations and combatant commander requirements resulting from climate change over the next 20 years."

This is a decidedly sharp deviation from the president's ambivalence toward—and on certain occasions, denial of—climate change. This summer, he opted to remove the United States from the Paris Climate Accords, and earlier this fall, the Environmental Protection Agency (EPA)—led by Trump's pick Scott Pruitt who, most observers agree, is systematically trying to dismantle the agency he is running—abruptly canceled a speech that EPA scientists were scheduled to deliver on climate change.

While the bill's main goals are to set forth 2018 programs and planning for the Department of Defense, it is certainly one of the administration's first official acknowledgments that climate change has negative effects, on the planet in general and on national security in specific. Secretary of Defense James Mattis is quoted in the bill, saying: "I agree that the effects of a changing climate—such as increased maritime access to the Arctic, rising sea levels, desertification, among others—impact our security situation."

Indeed, the law states: "It is the sense of Congress that, climate change is a direct threat to the national security of the United States and is impacting stability in areas of the world both where the United States Armed Forces are operating today, and where strategic implications for future conflict exist; there are complexities in quantifying the cost of climate change on mission resiliency, but the Department of Defense must ensure that it is prepared to conduct operations both today and in the future and that it is prepared to address the effects of a changing climate on threat assessments, resources, and readiness; and military installations must be able to effectively prepare to mitigate climate damage in their master planning and infrastructure planning and design, so that they might best consider the weather and natural resources most pertinent to them."

Here are others that acknowledge climate change in the law:

Chairman of the Joint Chiefs of Staff Joseph Dunford has stated: “It’s a question, once again, of being forward deployed, forward engaged, and be in a position to respond to the kinds of natural disasters that I think we see as a second or third order effect of climate change.”

Former Secretary of Defense Robert Gates has stated: “Over the next 20 years and more, certain pressures—population, energy, climate, economic, environmental—could combine with rapid cultural, social, and technological change to produce new sources of deprivation, rage, and instability.”

Former Chief of Staff of the U.S. Army Gordon Sullivan has stated: “Climate change is a national security issue. We found that climate instability will lead to instability in geopolitics and impact American military operations around the world.”

The Office of the Director of National Intelligence has stated: “Many countries will encounter climate-induced disruptions—such as weather-related disasters, drought, famine, or damage to infrastructure—that stress their capacity to respond, cope with, or adapt. Climate-related impacts will also contribute to increased migration, which can be particularly disruptive if, for example, demand for food and shelter outstrips the resources available to assist those in need.”

The Government Accountability Office has stated: “DOD links changes in precipitation patterns with potential climate change impacts such as changes in the number of consecutive days of high or low precipitation as well as increases in the extent and duration of droughts, with an associated increase in the risk of wildfire … this may result in mission vulnerabilities such as reduced live-fire training due to drought and increased wildfire risk.”

Read the full law here.