The  US military acts based on the civilian goals and objectives of the Congress and the President.
 
 The melting of the Arctic has clearly opened up the 'Northwest Passage", increased Russia's territorial desires in the area, and has altered military planning in that regard. 

No doubt many other effects will have to be responded to as well as detailed in the report put together by the source in your cite.  Their recommendations are consistent with many military principles and concerns.  

It should be noted, however,  that the report by these retired Generals was funded by the "Energy Foundation".

"Our mission is to promote the transition to a sustainable energy future by advancing energy efficiency and renewable energy."

http://www.ef.org/about-us/

Hardly an unbiased source.