By SIMON COLLINS, science reporter

An Auckland University geographer has been caught up in a political storm in the United States over a study which challenges the conventional wisdom over global warming.

Dr Chris de Freitas, who describes himself as a climate "agnostic", has been attacked in a US Senate committee hearing for letting the study appear in the journal Climate Research, where he is one of the editors.

The journal's editor-in-chief, Dr Hans von Storch, resigned in protest last week when the journal's publisher, Otto Kinne, refused to let him run an editorial saying that publication of the study was a mistake. Two other editors also resigned.


But the Bush Administration has welcomed the controversial study by two Harvard astro-physicists, which argues that temperature increases in the 20th century were no greater than in the Medieval Warm Period around 1000 years ago when Greenland was "green" and there were 50 vineyards in England.

According to the Wall Street Journal, White House staff edited a report from the Environmental Protection Agency to insert a reference to the Harvard study.

Dr Michael Mann, of the University of Virginia, told the Senate Committee on Environment and Public Works last week that Dr de Freitas was a well-known critic of the Intergovernmental Panel on Climate Change (IPCC) and the Kyoto Protocol, which aims to restrain global warming by cutting carbon dioxide emissions from cars and industry.

New Zealand, most European countries and Japan have agreed to sign the protocol, but the Bush Administration and Australia's Howard Government oppose it.

"Chris de Freitas, the individual in question, frequently publishes op-ed pieces in newspapers in New Zealand attacking IPCC and attacking Kyoto and attacking the work of mainstream climatologists in this area," Dr Mann told senators.

"So this is a fairly unusual editor that we are talking about."

Another editor of Climate Research, Dr David Legates, told the committee that "there were several people complaining that Chris de Freitas should be removed simply because he published the [Harvard] paper".

The senators, who included former first lady Hillary Clinton, did not comment directly on the allegations.


But a review editor for Climate Research, Professor Mike Hulme of the University of East Anglia in Britain, has sent an email to colleagues around the world noting that Dr de Freitas' editing of the journal had already been criticised over similar studies in 1999.

"Of 16 published papers de Freitas has been editor for, nine have been authored by scientists who are well known for their opposition to the notion that humans are significantly altering global climate," Dr Hume wrote.

Scientific American reported: "Some conclude that politics drove the paper's publication in Climate Research.

Dr de Freitas published a major study last year in the Bulletin of Canadian Petroleum Geology, edited by his brother Dr Tim de Freitas, of Talisman Energy in Calgary, arguing that "there is no reason to believe that catastrophic [climate] change is under way".

Dr Chris de Freitas said he had never received any research funding from petroleum companies and his brother had taken no part in the publication of his article in the Bulletin.

Dr Legates told the Senate hearing that when allegations were first made about the Harvard paper, the journal's publisher, Dr Kinne, asked Dr de Freitas to send him the comments from all four referees and the details of changes made.


"Essentially, what he concluded was that the reviewers provided good and appropriate comments; that [the authors] provided an appropriate addressing or incorporation of these concerns; and that Chris de Freitas provided analysis appropriately," he said.