CLIMATE change denier Christopher Monckton, who labelled Government adviser Ross Garnaut a Nazi, will be in Adelaide - at the German Club.

Aristocrat Lord Monckton slammed Professor Garnaut the Gillard Government's key climate change adviser while standing next to an image of a swastika.

German Club president Elke Pfau said yesterday Lord Monckton's comments were "unfortunate" and a "slur".

"It (the comment) is very ill-advised," she said, adding she would be "looking into" his booking at the club on July 22.

Footage of Lord Monckton's attack on Prof Garnaut during a US address emerged this week.

"Prof Ross Garnaut, that again is a fascist point of view," he says.

"Heil Hitler, on we go."

Lord Monckton is due to speak at the Association of Mining and Exploration Companies conference in Perth next week, then tour Australia, supported by the Climate Sceptics group.

Opposition leader Tony Abbott is scheduled to open the Perth mining conference.

The Climate Sceptics yesterday released a statement from Lord Monckton that was an apparent backdown.

"Let me begin with an unreserved apology. In a recent lecture, I should not have described the opinions of Prof Ross Garnaut, the Australian Government's climate economist, as 'fascist' ," it said.

But it was too late, with politicians on all sides roundly attacking his comments.

"The actions of Lord Monckton, I think, were offensive and grossly inappropriate," Prime Minister Julia Gillard said.

Former Coalition leader Malcolm Turnbull described Lord Monckton as a "vaudeville artist". "He has no credibility politically or scientifically - particularly in the UK," he said. "He's a professional sensationalist."

Greens leader Bob Brown called on Mr Abbott to withdraw from the conference.

"Tony Abbott should reconsider going to a conference in which inevitably he is consorting with Viscount Monckton. He will be measured against the vile words of that man in reference to Prof Garnaut," he said.

Mr Abbott said while the comments were "offensive" he would still attend the conference.

"Mining is a vital Australian industry," he said. "It's under serious threat from this government both from the carbon tax and the mining tax."