Newshub can reveal the cost to the New Zealand economy to meet Paris Agreement targets will be $1.4 billion every year for a decade.
But that money won't be spent on reducing New Zealand's domestic emissions - it’ll go towards paying other countries to reduce their emissions.
In documents released under the Official Information Act, a briefing to Judith Collins on her first day as Energy Minister says the cost to the economy of buying international carbon units to offset our own emissions will be $14.2 billion over 10 years.
Carbon trading is the process of buying and selling permits and credits to emit carbon dioxide.
In the documents, officials say "this represents a significant transfer of wealth overseas", and also warn "an over reliance on overseas purchasing at the expense of domestic reductions could also leave New Zealand exposed in the face of increasing global carbon prices beyond 2030".
The cost amounts to $1.4 billion annually.
The Green Party says the bill will only get bigger if no action is taken by the Government to reverse climate pollution, and continues to open new coal mines and irrigation schemes.
Co-leader James Shaw argues it’s cheaper for New Zealand to reduce domestic emissions, and it’s risky to take a gamble on an international carbon price which is subject to increase.
"The Government has always said it's too costly for New Zealand to reduce its own greenhouse gas emissions, but what these documents show is they haven't been completely straight with the public because they haven’t been talking about the cost of paying other countries to do it for us."
The Morgan Foundation calculated that in 2014, New Zealand spent about $3.9 million on carbon credits to offset its domestic emissions.
It’s not yet known where the money will come from to foot the $14.2 billion bill.
Businesses reliant on carbon-intensive transport will be required to buy international credits to account for their emissions, while the government will wear the cost of buying credits for industries exempt from the Emissions Trading Scheme such as agriculture.
New Zealand’s pledge under the Paris Agreement is to reduce emissions by 30 percent below 2005 levels by 2030.
Our domestic emissions are expected to increase overall by 2030.