Lawyers for the National Institute for Atmospheric and Water Research say a retired journalist should not be allowed to give evidence in a case brought against them by a climate change skeptics group because he is not an expert.

The New Zealand Climate Education Trust - a branch of the NZ Climate Science Coalition - are challenging Niwa figures which show a rise in temperatures in New Zealand of 1C over the past 100 years.

This figure is significantly higher than global warming figures around the world and the trust is questioning how Niwa calculated the figures and whether they are accurate.

It believes there has either been no warming or a trivial warming of around 0.2C.

In submissions to the court, lawyer for Niwa, Justin Smith, has argued some of the evidence the anti-climate change group has brought before the court should be inadmissible because the man presenting, Terry Dunleavy, is a journalist not a climate scientist.

"He does not depose to having any qualifications or training in climate science and does not disclose any significant experience in this field."

Smith's submissions say Dunleavy has merely read the work of others and either endorsed it or presented it as his own.

Niwa denies the trust's claims.

Earlier this week Terry Sissons, lawyer for the trust, said Niwa could have obtained inaccurate New Zealand average temperatures due to 'sudden site relocations' and by regularly changing temperature gauging instruments.

"We're not saying that climatic changes are not happening but let's at least ensure the evidence gathered for the benefit of New Zealanders is accurate and is done properly,'' Sissons said.

The case relates to information supplied on Niwa's website and in particular a graph called the 'seven station series'  which it claims carries the 'New Zealand Temperature Record' from 1853 right up to modern day climate records.

The seven station series temperature figures have been referred to in numerous tribunals and have previously been given significant credence but, in 2009 the trust released a research document 'Are We Feeling Warming Yet' which claimed that the warming trend was occurring as a result of Niwa's in-house corrections and variations.

The case is expected to finish tomorrow.

- © Fairfax NZ News