United Nations sign historic Paris climate deal
Amid hope and hype, delegates have finished signing the Paris climate agreement at UN headquarters in New York.
Some 171 countries inked the deal today, a record number for a new international treaty.
About 15 nations, mainly small island states, had already ratified the agreement.
But dozens of other countries were required to take this second step before the pact came into force.
David Shukman reports.
22 Apr 2016