CSIRO scientists who say they were gagged from talking about greenhouse emissions have had a “walk in the park” compared to those who dared question thescience behind global warming.

Climate expert and retired founder of the Antarctic Co-operative Research Centre Garth Paltridge said yesterday he was told to keep quiet in the early 1990s when he suggested there was doubt about the science behind global warming.

Professor Paltridge said a senior CSIRO chief threatened to pull the agency’s promised funding for the Antarctic Research Centre, an institution designed to examine the role of Antarctica in the global climate, if he persisted in making his claims publicly.

The threats were made when the CSIRO had applied for tens of millions of dollars in research funds from the newly formed Australian Greenhouse Office.

The claims by Professor Paltridge, now an emeritus professor with the University of Tasmania, come in the wake of accusations by retired CSIRO scientists that they were gagged from talking about global warming in ways that reflected poorly on government policy.

One claimed he was told not to talk about ethanol and another said he was ordered to remove from a report a section referring to how rising sea levels could lead to millions being displaced in Asia and the Pacific.

Professor Paltridge said it was far more difficult for any scientist reliant on public research dollars to go against the accepted wisdom that global warming would be disastrous.

He said one of the fundamental reasons scientists had gone overboard on global warming was because they could feel like “knights in shining armour fighting the good fight against the terrible enemy of multinational business”.

While he did not question that putting more carbon dioxide into the atmosphere would warm the planet, Professor Paltridge said evidence suggested thetemperature rise would be less than a degree over the next 100 years, not the seven or eight degrees regularly predicted.

“The climate debate has become politically correct,” he said. “It is quite difficult to propound a view that goes against that view. In my experience censorship of the other side of the debate has been much more extreme. Those advocating cutting greenhouse emissions have had a bit of a walk in the park when it comes to being censored.

“To go against the popular beliefs on global warming you are being politically incorrect. People are willing to believe politically correct rather than factual arguments, that is the danger of it all.”

A CSIRO spokeswoman said the alleged censorship was in the early 1990s and was too long ago to make comment.

This week CSIRO chief executive Geoff Garrett announced a review of the organisation’s role in providing scientific input into policy development by a team of leading scientists.

The team held its first meeting yesterday and is expected to report in three months.