CMIP5 - Data Access - Data Portal
CMIP5
The CMIP5 Data is now available through the new portal, the Earth System Grid - Center for Enabling Technologies (ESG-CET), on the page http://pcmdi3.llnl.gov/esgcet .
You may search or browse through the Earth System Grid data holdings, but you will need to create an account to download the data. To create get a new account go to Account -> Create_new_Account .
It is highly recommended that read 'Getting started' page first.
See also IPCC AR5 timetable for estimation of due dates for some IPCC"s Fifth Assessment Report (AR5) activities.
CMIP3
If you would like to check the CMIP3 data portal, it is available throught the Earth System Grid (ESG) portal.
You may search or browse through the Earth System Grid data holdings, but the registration is required to download data.

CMIP5 Status