The decision to sack climate scientist Jim Salinger was not taken lightly, the Employment Relations Authority was told today.

Dr Salinger is seeking compensation through the authority after claiming he was unjustifiably dismissed by his former employer, the National Institute of Water and Atmospheric Research (Niwa).

He was dismissed for allegedly ignoring a Niwa policy against speaking publicly without prior approval.

Under cross-examination from Dr Salinger's lawyer Alex Hope, Niwa's human resources general manager Mary-Anne Dehar said Dr Salinger had not received a warning before his dismissal.

"He was not formally put on notice but if he repeated a particular conduct again he would face dismissal," Ms Dehar said.

She added that she thought Niwa's regional manager Ken Becker had put in a "huge amount of effort" coaching and supporting Dr Salinger.

"There's very few dismissals with Niwa, which tries very hard to be a good employer," Ms Dehar said.

Mr Hope asked Ms Dehar how much consideration was given to Dr Salinger's seniority as a scientist and the length of time he had worked for Niwa.

She said his dismissal was never taken lightly.

"Serious consideration was given to all relevant factors, and was processed over six or seven weeks. The ultimate decision was not something made quickly," Ms Dehar said.

Mr Hope asked Ms Dehar how the investigation was conducted.

"Ken Becker came to me and outlined his concerns about Dr Salinger's behaviour. He sought my advice about what to do about it.

"There was a pattern of behaviour which occurred over various weeks. I didn't think it would be responsible as an employer to let things lie," Ms Dehar said.

Mr Hope said this wasn't a record of an investigation, it was just an allegation about what someone did to resolve it.

Niwa sacked Dr Salinger, a scientist of 35 years who had worked for Niwa since its inception in 1992, over three alleged breaches of its code regarding media conduct.

Dr Salinger earlier this week told authority member Leon Robinson that he had breached the policy in regard to a Radio New Zealand interview in February this year.

But he denied he breached the policy over two contacts he had with TVNZ this year. He said he believed the policy stopped him from making statements but not from contacting media by phone.

Mr Robinson has also heard accounts this week of disputes other staff had with Dr Salinger, though they were not among the reasons he was dismissed.

Dr Salinger is not seeking his job back but does want compensation for lost income up to 2012, along with $104,000 lost superannuation money and $50,000 in compensation for humiliation and loss of dignity.

The hearing is expected to finish tomorrow.

- NZPA