United Nations Secretary-General Ban Ki-Moon

United Nations Secretary-General Ban Ki-Moon

Janek Skarzynski/AFP/Getty Images

Ban Ki-moon, secretary-general of the United Nations, urged nations to ratify the second commitment period of the Kyoto Protocol, step up financial aid for developing countries and commit to more ambitious emissions-reduction targets to keep warming below the internationally agreed limit of 2 degrees Celcius (3.6 Fahrenheit) since industrialization.