Questions are being asked about whether it's worth spending so much money on carbon credits, which will end up overseas.
Briefing papers show the Government could have to buy credits worth $14 billion over a decade, to meet its Paris Climate Agreement obligations.
New Zealand can only meet about 20 percent of our target at home - the rest will have to be met by carbon credits.
Our first climate change ambassador, Dr Adrian Macey, said it's three times what we spend on the environment and two and a half times our annual aid budget.
He told Mike Hosking it's a lot of money going offshore with no direct benefit to the New Zealand economy.
"And storing up longer-term problems for New Zealand when at some point it has to make its emissions reductions at home."
Dr Macey said if you purchase emissions, you're not reducing domestic emissions.
"And so we're going to get a bill in 2020 to 2030, and if we haven't reduced our domestic emissions by then, we're going to have to take on another target after 2030."
LISTEN TO THE FULL INTERVIEW WITH DR ADRIAN MACEY ABOVE