United Nations Secretary General Ban Ki-moon poses with a bamboo bicycle, made by Evelyn Ohenewaa Gyasi (R) in Ghana as part of efforts to tackle climate change during a session of United Nations Climate Change Conference COP 19 on November 20, 2013 in Warsaw. AFP PHOTO / JANEK SKARZYNSKI        (Photo credit should read JANEK SKARZYNSKI/AFP/Getty Images)