Forestry companies say there will be a mass exit from the Emissions Trading Scheme if the Government commits to the second phase of the Kyoto Protocol.
That's because a rule which prevents New Zealand having to pay for carbon from forestry over the period from 1990 to 2008 has been removed for the next phase, which is expected to start next year.
That would mean having to backpay 18 years worth of forestry emissions.
City Forests chief executive Grant Dodson says his company will remove its 4000 hectares of forest from the Emissions Trading Scheme if the rule is not there.
Earnslaw One holds the same view.
International Climate Change Negotiations Minister Tim Groser says the Government has not yet decided if it will commit to the agreement.