The incoming National government will completely review the emissions trading scheme (ETS) - possibly including the science that says humans are to blame for climate change - as part of its support deal with Act.
But Prime Minister-elect John Key is still confident an amended ETS will be passed into law before the end of next year.
National campaigned on watering down the existing legislation within nine months to reduce what it said were barriers to economic growth.
But Act campaigned on scrapping the ETS and has questioned whether human-induced climate change actually exists.
Under Act's support agreement a "special select committee" will be set up to review the current ETS and any proposed amendments "in light of the current economic circumstances".
A draft terms of reference for the review attached to the agreement, includes hearing "competing views on the scientific aspects of climate change" and looking at the merits of a "mitigation or adaptation approach".
It also includes looking at the merits of an ETS, as opposed to a carbon tax, and the timing of any future climate change interventions.
The deal requires the National government to pass immediate legislation delaying the implementation of the ETS until the review is complete.
It also requires the lifting of a ban imposed this year on non-essential new fossil fuel-based power generation.
Mr Key today played down the significance of the draft terms of reference for the review, saying they were a proposal from Act and the final terms would be altered after National input.
He said he personally believed human-induced climate change was real and it was still possible National would pass an amended ETS into law within the time-frame it had promised - which "broadly speaking" was the end of September next year.
If that deadline could not be met he was confident changes could be passed before the end of 2009.
He said that would give businesses enough certainty as the existing scheme did not take effect until 2010.
"I'm quite confident the select committee will come up with what we always wanted which is more balance in this whole debate."
Mr Key said lifting of the ban on fossil-fuel power generation would not lead to a blow-out in emissions as planned Resource Management Act changes would make it easier for companies to get the green light for large-scale renewable projects.
Mr Hide said he was happy with the "fundamental review" of the legislation, given that Act had only won 3.7 per cent of the vote.
"We look forward to having a proper consideration ... of the whole scheme."