Prime Minister John Key has defended New Zealand's emission reduction targets after the Green Party released a plan it says can dramatically reduce greenhouse gas emissions.
The Government has announced a target of reducing emissions to 11 percent below 1990 levels by 2030, in preparation for a major United Nations climate change conference in Paris later this year.
International climate change analysts have repeated their criticism of the target, saying it is inconsistent with the country's long-term goal.
The Climate Action Tracker said targets such as New Zealand's would lead to the planet warming well beyond 2degC - and possibly as high as 4degC.
But Mr Key has rejected criticism that the target is inadequate, and said New Zealand would do more when technology became available to reduce agricultural emissions.
Green Party co-leader James Shaw said the target was not good enough to mitigate climate change.
He has unveiled a plan to reduce emissions by 40-percent below 1990 levels in the same time frame.
"We think it's very achievable. It's hard work, but it's entirely doable.
"And our challenge to the government, who keep saying we cannot do better than 11 percent reduction because of agriculture, is actually, what we've demonstrated, is that you can achieve a 40 percent reduction, even including agriculture," he said.