New Zealand will line up with more than 100 other countries behind the so-called 'high ambition' target to limit global temperature rises to 1.5ºC
Climate Change Minister Tim Groser told BusinessDesk from global climate change talks in Paris the move came with Prime Minister John Key.
New Zealand, he said, will support a 1.5ºC rather than a 2ºC goal, coinciding with a meeting with Pacific Island delegations to the Paris talks.
New Zealand had been holding out for the previously widely accepted goal of trying to limit global warming to no more than 2ºC.
It appears to have buckled following unexpected support for the more ambitious target from US Secretary of State John Kerry, in Paris on Wednesday.
Australia had already moved ahead of New Zealand in accepting the aspirational 1.5ºC warming limit target.
Mr Groser said it had been his view that limiting global temperature rise to 1.5ºC was unachievable, but he didn't want the potential for an agreement in Paris to founder over an issue of "aspirational language".
"Since it's obviously so important to Pacific Island countries (some of which face possible inundation as sea levels rise), we've said 'OK'," he said.
Mr Groser remains confident a final agreement will be stitched together at the Paris talks.
"The atmosphere is not the nasty, cantankerous, pernicious atmosphere of Copenhagen. While failure is possible, I will be astonished if it fails."
The result would be that the world would move from "a ludicrously partial coverage of emissions to covering 90 per cent of emissions".
At this stage, there were no red flags for New Zealand in the emerging agreement, although neither New Zealand nor the US would accept proposals that would make developed countries legally liable to fully compensate developing countries for natural disasters created by more extreme weather.
"The reality is that whenever a hurricane goes through the Cook Islands or somewhere else in the Pacific, New Zealand and Australia step up," said Mr Groser.
"But we won't live with language that says we are legally liable to fully remedy loss and damage."
Mr Groser said he had received no criticism from government delegations in Paris on New Zealand's stance on agricultural emissions, despite heavy criticism from environmental activists.
"The climate has shifted on agriculture," Mr Groser said. "People realise we are dealing with the issue."