The government is setting up an interim climate change committee to help meet its promise to make New Zealand carbon neutral by 2050.
Climate Change Minister James Shaw said a new government bill would put the new climate change target into law and establish an independent Climate Commission.
There was a lot of economic research that had to be done before the bill can be introduced, he said.
"The last set of macro-economic research we did hasn't been redone since about 2013, 2014," he said.
"Even then it was a bit of a once-over-lightly approach, it had very narrow parameters and made a number of assumptions that were wildly incorrect."
Mr Shaw acknowledged that hitting net zero greenhouse gas emissions by 2050 was going to be tough.
"We've got a pretty steep curve ...but that's true of the whole planet, right?
"We've been talking about this for a number of decades. I think everyone, not just New Zealand but all around the world, is waking up to the reality that it is time for a little less conversation and a little more action."
The intention is to introduce the legislation by October next year, and pass it by mid-2019.