Every president since Lyndon Johnson has recognized the security risks of climate change. Then came Trump.

President Donald Trump 's administration has purged environmental security studies from public record.

John Defterios: Environmental factors pose direct, indirect, and accelerating threats to US forces, operations, bases, and national security interests.

He says the actions will not reduce the actual risk that environmental problems pose for national security or the military.

The stress from these challenges is already contributing to political conflict, he says.

Climate change will increasingly exacerbate risks to US national security interests, authors say.

Outmoded security concepts like realpolitik, focused on narrow “superpower competition,” together with deep climate denial, were in ascendency.

The first Trump administration censored words like climate change’ in government documents and narrowed security concerns to single-nation competition.