The Climate Action Joint Committee has existed since March.
Just three tāngata whenua members were planned, but during discussion with the region's mayors, hapū and iwi it became clear that equal representation was expected and the council's Long Term Plan allows for up to eight tāngata whenua members.
Horizons chairwoman Rachel Keedwell, who will be co-chair of the committee, said there was much enthusiasm for the model.
"We are setting up working with iwi on other committees as well. It's important to have a framework in place."
Councillors were asked to approve payment of $500 a day for committee members, and $775 a day for the co-chairs.
"It's a huge cost, with no benefit whatsoever to the ratepayer," councillor Bruce Gordon said.
Councillor Jono Naylor said it was the only way people got paid for such work and the appointees would likely put in three to 10 hours of reading and discussion before coming to a meeting.
Councillor Sam Ferguson said expecting people to do the work voluntarily was not appropriate.
"[This] organisation is on a journey and where we head with co-governance is another step in that direction."
Councillor Fiona Gordon wanted a workshop to clarify how unelected members of council groups would be paid, and that was agreed to.
The seven new appointees will be back-paid when the council has finalised its framework.