Others from a military background are equally sober, including former US Supreme Allied Commander in Europe Wes Clark, who sent out an e mail yesterday linking to a "virtual march" on Washington to "stop climate change", and US Senator John McCain.
Today, openDemocracy publishes an article on some of the hard security challenges presented by climate change. John Ashton and Tom Burke are seasoned environmentalists who have seen action inside government and industry. (Neither nurses ambitions to be US president, so far as we know!). They conclude:
"We have mobilised on the necessary scale in the past when the threat or opportunity has been clear. It is a challenge more to our wisdom than to our ability, more to our values than to our resources, more to our aspirations than to our fears".