Despite President Trump’s past dismissal of climate change, one senior-level member of his cabinet has reportedly admitted that it does pose a key threat.

Despite President Trump’s past dismissal of climate change, one senior-level member of his cabinet has reportedly admitted that it does pose a key threat. 
ProPublica reports that “Secretary of Defense James Mattis has asserted that climate change is real, and a threat to American interests abroad and the Pentagon’s assets everywhere…”
The site says it was able to access Mattis’ “unpublished written testimony provided to the Senate Armed Services Committee after his confirmation hearing in January…”
In the document, he reportedly states, “Climate change is impacting stability in areas of the world where our troops are operating today. It is appropriate for the Combatant Commands to incorporate drivers of instability that impact the security environment in their areas into their planning.” 
He has also been quoted as telling lawmakers, “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.”
And when he was asked about how to approach the threat, he said, “...climate change is a challenge that requires a broader, whole-of government response. If confirmed, I will ensure that the Department of Defense plays its appropriate role within such a response by addressing national security aspects.” 
This position seems counter to President Trump's who has voiced skepticism about global warming in the past.
In November 2012, Trump claimed that China invented a hoax that climate change is happening. He tweeted, “The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive.”
According to CNBC, the administration’s Environmental Protection Agency chief, Scott Pruitt, also recently came under fire for questioning if carbon dioxide contributes to global warming.