The decision to prepare a Fifth Assessment Report (AR5) was taken by the members of the IPCC at its 28th Session (09-10 April 2008, Budapest, Hungary).
Following the election of the new IPCC Bureau at the 29th Session of the IPCC (31 August - 04 September 2008, Geneva, Switzerland) and discussions about
future IPCC activities at the 30th Session of the IPCC (21-23 April 2009, Antalya, Turkey), a Scoping Meeting was held (13-17 July 2009, Venice, Italy)
to develop the scope and outline of the AR5. The resulting outlines
for the three Working Group contributions to the AR5 were approved by the 31st Session of the IPCC in Bali (26-29 October 2009).