Though Mattis has acknowledged climate change as a national security issue in the past, including as commander of Joint Forces Command in the 2010 "Joint Operating Document," the statements, published Tuesday by ProPublica, are the first time he has done so as a member -- or, at the time, nominee -- of the Trump administration.
“Climate change is impacting stability in areas of the world where our troops are operating today,” Mattis said in response to a question from one unnamed Democratic senator. “It is appropriate for the Combatant Commands to incorporate drivers of instability that impact the security environment in their areas into their planning.”
“Climate change can be a driver of instability and the Department of Defense must pay attention to potential adverse impacts generated by this phenomenon," he told Sen. Jeanne Shaheen (D-NH), who asked if he viewed climate change as a national security threat.
Shaheen asked how the military should prepare for "this threat" of climate change.
“As I noted above, climate change is a challenge that requires a broader, whole-of government response," Mattis responded. "If confirmed, I will ensure that the Department of Defense plays its appropriate role within such a response by addressing national security aspects.”
“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rising sea levels, desertification, among others — impact our security situation," Mattis said in response to another unpublished question. "I will ensure that the department continues to be prepared to conduct operations today and in the future, and that we are prepared to address the effects of a changing climate on our threat assessments, resources, and readiness.”
The statements, shared with ProPublica by an unnnamed source "involved with coordinating efforts on climate change preparedness across more than a dozen government agencies," were later confirmed by Senate staff, the publication reported.
Mattis' acknowledgement of climate change, and his assertion that it requires a "whole-of government" response, appears more urgent than other top members of the Trump administration.
On Thursday, EPA administrator Scott Pruitt said during an interview on CNBC that he did not agree that carbon dioxide emissions were the primary "control knob for climate."
“No, I think that measuring with precision human activity on the climate is something very challenging to do and there’s tremendous disagreement about the degree of impact," Pruitt said. "So no, I would not agree that it’s a primary contributor to the global warming that we see. But we don't know that yet."