see more

US Secretary of State John Kerry delivers a speech at the Mashable/UN Foundation "Earth to Paris" Summit during the COP 21 United Nations conference on climate change on December 7, 2015 at Le Petit Palais in Paris. / AFP / KENZO TRIBOUILLARD (Photo credit should read KENZO TRIBOUILLARD/AFP/Getty Images)

US Secretary of State John Kerry delivers a speech at the Mashable/UN Foundation "Earth to Paris" Summit during the COP 21 United Nations conference on climate change on December 7, 2015 at Le Petit Palais in Paris.  / AFP / KENZO TRIBOUILLARD        (Photo credit should read KENZO TRIBOUILLARD/AFP/Getty Images)