See Candidate Page Pete Buttigieg, Climate, International, National Security Climate tweets on Buttigieg 6/11/19 Pete Buttigieg, to rousing applause: "We must treat climate change as the existential security challenge that it is." https://t.co/mt64os1W7M pic.twitter.com/YMsut7pRA8— Evan McMurry (@evanmcmurry) June 11, 2019