There are concerns the newly passed Emissions Trading Scheme (ETS) could end up costing Kiwis jobs.
The Minister for Climate Change James Shaw said the Bill, which passed late Tuesday evening, will be one of the most effective tools the country has for reducing climate-polluting emissions.
But industry groups say there are "serious concerns" about some of the reforms.
"There's some goods parts that we agreed with and there were obviously some changes we wanted to happen," vice-president of Federated Farmers, Andrew Hoggard, told Magic Talk's Rural Today on Thursday.
Hoggard said the biggest worry is the Bill incentivises the acceleration of productive farmland being converted to pines planted for carbon credits.
"If we're going to see the carbon price increase quite significantly, which is possible under this legislation, we're worried about the drive for more carbon-credit farming speculation occurring, with hill country farms being bought out, just mass planted into pines and the impact that is going have on a lot of communities," he said.
"Certainly you talk to farmers in the Wairarapa, through to Tararua, Hawke's Bay, up into the East Coast - it's a real concern for them."
He said Federated Farmers estimate that since last year around 70,000 hectares of productive beef and sheep land has already been converted into pine-planted carbon-credit forestry.
"There's no doubt that there are sections of land on a number of farms that would be better off in trees, but not the entire farm," he said.
"70,000 hectares is a bloody big amount."
Those figures differ from the Government's numbers, however, which says only 11,000 hectares have gone to planting. Hoggard said the difference may be due to the fact his organisation is counting "what is sold with intention" while the Government counts just land that has "pines in the ground".
His main fear, he said, was that if productive farmland is lost to carbon-credit forests the farming infrastructure will also disappear.
"The fences are all gone, the water reticulation is all gone. It becomes a massive challenge to try and reinstitute that and as a country we've sort of lost the opportunity to be producing goods that are real goods, real things - mutton chops and lamb chops and wool. This is stuff that creates jobs and communities so carbon credits aren't going to create these jobs and communities."
He said although there was "no real easy answer", the situation needed to be addressed.
"It's a real concern and we've got to make sure that we're getting the balance right and we're thinking long term about what is in New Zealand's long-term interest here."
The Government has rejected the criticism, calling the new emissions trading scheme one of the most ambitious in the world.
"Until now, the ETS has not fulfilled its primary purpose, which is to reduce emissions," said Shaw.
"Taking action to fix this puts us further ahead on climate action than many other parts of the world."
Hoggard said despite his complaints over incentives for carbon credits, Federated Farmers was "very pleased" the Government had agreed to take up the Primary Sector Climate Change Commitment, which encourages a sector-driven approach to lower emissions on farms rather than merely introducing a processing levy on farmers.