Leading climate scientists from three countries have called for radical changes to the United Nations' climate change panel as it faces intense scrutiny.

NZ experts say the Intergovernmental Panel on Climate Change (IPCC) should simply follow its own rules to avoid slips such as the 2007 error exaggerating the speed of glacier melt in the Himalayas.

But four of five climatologists who were asked to propose solutions in the international journal Nature suggested more radical options. The Nature article, released yesterday, asked: "IPCC: cherish it, tweak it or scrap it?".

Mike Hulme, an IPCC lead author of the University of East Anglia in England, said the panel should be split after its 2014 report to part the physical scientists who observe and predict climate change from a separate policy analysis group. A third group would carry out regional assessments.

He wanted six-yearly assessments covering all aspects of climate change scrapped in favour of policy reports on options such as carbon border tariffs and ways to slow deforestation.

A separate group of physical scientists would write "smaller, sharply focused" updates on the science.

Jeff Price, a lead author on the third and fourth IPCC reports, said the process was too slow: "A new class of short, rapidly prepared, peer-reviewed reports is needed."

And Eduardo Zorita of the GKSS Research Centre in Germany said the IPCC should be replaced by an "International Climate Agency", perhaps with 200 staff. He said the International Atomic Energy Agency, the European Central Bank or the US Congressional Budget Office showed it was possible to be independent and respected.

John Christy of the University of Alabama suggested turning the IPCC into "a living, Wikipedia-IPCC" open to published scientists, to be updated online and with sections overseen by groups of four to eight experts.

Several experts said a problem was that the IPCC produces its main reports only once every six years. The last was in 2007 drawing on the work of 2500 experts and totalling about 3000 pages.

But Thomas Stocker of the University of Bern, a co-chair of one of the IPCC's three main working groups, defended the panel's existing plans, saying reports every six years ensured "the robustness required for a thorough assessment".

He said the panel had fulfilled its role as an "honest broker" with "remarkable rigour and integrity".

New Zealand climate scientists agreed, saying that rather than "fixing" the panel its facilitators should be asking why the Himalayan glacier paper made its way into a report and how it was not picked up.

"It is ... clear that this mistake could have been avoided," said Victoria University climate researcher Andy Reisinger, "if all people involved in the process ... had meticulously followed the existing guidelines.

"Asking for wholesale revision to the IPCC in the wake of this mistake appears to be throwing out the baby with the bathwater, and dismantling the bath tub as well, when all it needed was a reminder to clean behind the ears."

An error that Himalayan glaciers could melt by 2035 - a huge exaggeration of the thaw - led to calls for reforms of the panel that shared the 2007 Nobel Peace Prize.