Pressure on the Intergovernmental Panel on Climate Change (IPCC) has intensified since it apologised last month for incorrectly reporting that Himalayan glaciers could disappear by 2035.

Many subsequent criticisms have focused on the panel's use of ''grey literature'' - work that has not been peer reviewed by other scientists including student thesis, reports by green groups and magazine articles - in parts of its 3000-page report.

Writing in respected journal Nature, contributing author Eduardo Zorita said the IPCC was experiencing a failure of trust.

He called for it to be made stronger and independent so that it drew only on established peer-reviewed literature and highlighted gaps in the published science. Opposing views would be included.

Dr Zorita, from the GKSS Research Centre in Germany, said the IPCC's use of government-nominated academic volunteers working under unmanageable deadlines had put it ''at the mercy of pressure from advocates''.

Former IPCC co-ordinating lead author Mike Hulme said the huge expansion in its work since it was created in 1988 meant the panel was ''no longer fit for purpose'' and needed a complete overhaul after its next report in 2014.

The University of East Anglia scientist said it should be replaced by a smaller IPCC-like science panel that reported more regularly, up to 10 regional panels looking at related local economic and social changes and a policy analysis body.

Former lead author John R. Christy, from the University of Alabama, said the panel should be removed from UN oversight and could be replaced by a ''wikipedia-IPCC'' run by a rotating cast of authors. He said the evidence for dissenting views should also be examined.