Puerto Rico aerial aftermath September 2017 (copy)

Debris scatters a destroyed community in the aftermath of Hurricane Maria in Toa Alta, Puerto Rico. AP Photo/Gerald Herbert, File

President Donald Trump just made clear what he views as America’s top national security challenges — showdowns with China and Russia, tension on the Korean Peninsula and in the Middle East. He also made clear what he does not see as a problem — climate change.

Mr. Trump released his draft national security strategy on Monday, and unlike his predecessor, climate change is not referred to as a security threat. On the contrary, the only mention of climate change comes in a subsection on “energy dominance” that reasserts the Trump administration’s opposition to an “anti-growth energy agenda.”

That is a dangerous shift of priorities.

A national security strategy is mandated by Congress. And obviously each president is free and indeed expected to reflect his worldview and political priorities in the document. Mr. Trump’s departure from President Obama’s strategy is not at all surprising.

But Mr. Trump’s decision to downplay the importance of climate change as related only to energy policy rather than as a dominant force shaping global political, economic and social movements willfully ignores reality. And it goes against the stated advice of top military officials.

A 2015 Department of Defense report acknowledged that climate change “will aggravate problems such as poverty, social tensions, environmental degradation, ineffectual leadership and weak political institutions that threaten stability in a number of countries.”

In July, Secretary of the Navy Richard V. Spencer said that he is “totally aware” of the various challenges at home and abroad posed by climate change, including “rising water issues.” Those same concerns menace Charleston and the rest of coastal United States.

And Secretary of Defense James Mattis said earlier this year that “climate change can be a driver of instability.”

Military leaders understand that climate change is not an abstract problem for future generations but rather a reality that is causing and exacerbating unrest, extremism and violent upheaval all around the world due to drought, famine and other environmental catastrophes.

They recognize that higher seas and stronger storms are already battering cities here in the United States. Hurricanes Harvey, Irma and Maria caused tens of billions of dollars in damage in Texas, Florida, Puerto Rico and even here in South Carolina that will take years to fully repair.

Mr. Trump must heed their advice.

The risks of inaction grow with each passing year, and ignoring the impacts of climate change now will make it harder to mitigate and prepare for those impacts later.

President Trump has said he was elected “to represent the citizens of Pittsburgh, not Paris.” He’s right, of course. But climate change affects people in Pittsburgh just as much as it affects people in Paris — and everywhere else.

His national security strategy should reflect that fact.