see more

US President Barack Obama (5thL) is greeted by world leaders as he arrives for the family photo at the COP21, United Nations Climate Change Conference, in Le Bourget, outside Paris, on November 30, 2015. More than 150 world leaders are meeting under heightened security, for the 21st Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21/CMP11), also known as 'Paris 2015' from November 30 to December 11. AFP PHOTO / POOL / MARTIN BUREAU / AFP / POOL / MARTIN BUREAU (Photo credit should read MARTIN BUREAU/AFP/Getty Images)

US President Barack Obama (5thL) is greeted by world leaders as he arrives for the family photo at the COP21, United Nations Climate Change Conference, in Le Bourget, outside Paris, on November 30, 2015. More than 150 world leaders are meeting under heightened security, for the 21st Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change (COP21/CMP11), also known as 'Paris 2015' from November 30 to December 11. AFP PHOTO / POOL / MARTIN BUREAU / AFP / POOL / MARTIN BUREAU        (Photo credit should read MARTIN BUREAU/AFP/Getty Images)