Green MP says it is among worst foreign policy calls made by NZ and would weaken its hand in future talks.
Green MP Kennedy Graham says New Zealand's decision not to sign up to the Kyoto Protocol again was an economic mistake and will void New Zealand's influence over climate change for the next eight years.
After two weeks, United Nations climate-change talks in Doha wrapped up yesterday with an agreement to work towards a binding global treaty by 2015 to take over from the Kyoto Protocol in 2020 and include countries such as China, India and the United States.
In the meantime, 37 countries - including Australia and European nations - signed up to further binding commitments under the Kyoto Protocol through to 2020.
Despite lobbying from European countries, New Zealand stuck to its decision to opt out of Kyoto along with Canada, Russia and Japan. Instead, it will set a non-binding target through to 2020, expected to aim to cut emissions by 10 to 20 per cent.
Climate Change Minister Tim Groser defended the decision, saying it was time to look beyond Kyoto, which covered only 15 per cent of the world's emissions.
However, Dr Graham said it was one of the worst foreign policy decisions a New Zealand government had ever made and would weaken New Zealand's hand in future talks.
He said it was also an economic mistake because New Zealand would lose access to Kyoto's carbon market, on which credits are traded to enable countries to meet their obligations.
"Being excluded for a five-year period from access to the flexible mechanism for trading would harm New Zealand's economic interests as much as any policy decision this Government has yet made.
"It would be politically stupid, morally offensive and economically harmful, and come to haunt us in the coming years," he said.
Access to that market was one of the primary reasons Australia signed up to Kyoto again, with its Trade Minister, Craig Emerson, saying it would give businesses access to a predictable global emissions market.
Mr Groser said New Zealand would have access to those carbon markets until at least 2015. He could not say what would happen at that point, saying that would depend on progress in talks for the new 2015 pact, as well as discussions about other regional carbon trading markets.
He said New Zealand would maintain its emissions trading scheme.
"But the Government has no intention of forcing NZ businesses and households to pay higher than world prices in the current difficult international economic climate."
Mr Groser said he was satisfied New Zealand had the right long-term approach. "We have every expectation that further progress will be made, but it will be slow, incremental and controversial," he said.
The countries at Doha also agreed to a set up a process for richer countries to compensate small, poor countries for the damage done by the effects of climate change, such as rising sea levels.
That decision was seen as ground-breaking because of the implicit admission that the wealthier emitting countries were responsible for some of that damage.
Countries already commit to funds for climate change adaptation and mitigation - such as the "fast-start finance" fund set up in Copenhagen in 2009.
New Zealand contributes $30 million a year to that and is committed to continuing contributions.By Claire Trevett @CTrevettNZH Email Claire