Concern is growing over the near collapse of the country's carbon market as the price of emission units plunges.
High carbon prices are supposed to deter companies from emitting greenhouse gases, and a low price means firms might find it cheaper to keep emitting than to expensively re-tool their factories.
The price of units has fallen to below $2 and specialist publication Carbon News reports some international units are trading as low as 15 cents.
Editor Adelia Hallett said the cost of carbon credits has halved in the past seven months and there are fears the price will fall further.
She said the low price is deterring foresters from planting trees, which is a critical part of the Government's plan to reduce New Zealand's overall greenhouse gas emissions.