The Government has been questioned over whether a fall in its ranking on its aims to reduce greenhouse gas emissions will prompt stronger action.
New Zealand's conditional target for cutting between 10 and 20% of emissions on 1990 levels by 2020 has dropped from being moderate to inadequate by a climate analysis group.
On Tuesday, Prime Minister John Key cited the moderate ranking as evidence that New Zealand was in good shape.
On Wednesday the Green Party questioned the Government over whether the downgrade would result in a tougher target.
But Deputy Prime Minister Bill English said the target was credible and would be defended at the Copenhagen talks.