Act leader David Seymour last week confirmed he would oppose the Government's Zero Carbon Bill.

"New Zealand's actions are not going to change the climate. We account for just 0.17 per cent of global emissions," he said.

"In fact the Prime Minister has made very clear that the Zero Carbon Bill is simply about trying to show global leadership.

"As with her Government's positions on oil and gas exploration, gun laws and social media, the Prime Minister is more concerned about a global audience than good policy-making. But the idea that the United States, China, India and other large emitters will follow our lead on climate change is naïve.


"New Zealand will not prosper if we are forced to make significantly deeper emissions cuts than our trading partners. We will simply impoverish ourselves and push economic activity to other countries."

The New Zealand Institute of Economic Research had warned that New Zealanders could lose a quarter of what would have been their 2050 incomes, and that losses would be disproportionately felt by low-income earners.

The legislation, as proposed, was expected to reduce gross domestic product by 10 to 22 per cent in 2050, with the poorest 20 per cent of households being hit twice as hard because the price of goods and services would rise.

"Tailrisk Economics has called the nett zero emissions by 2050 target a 'feel good' project, which will cost the economy $200 billion and is unlikely to have any impact on the behaviour on the rest of the world," Mr Seymour added.

"The Zero Carbon Bill would be a boon for bureaucracy but may have little, if any, effect on emissions.

"Allowing for economic growth and long-term trends, the UK Climate Change Act has seen that country reduce its emissions no faster than New Zealand since 2008. Our own Productivity Commission reports that the UK will be even less effective in the future as the low-hanging fruit are picked.

"The risk of shooting ourselves in the foot is very real. If we set more aggressive targets than other countries it will not only harm the economy, but also force activity to less efficient jurisdictions, actually increasing global emissions.

"The Government's approach to climate change is cumbersome and bureaucratic. A more sensible approach would be to simply tie the carbon price charged under the Emissions Trading Scheme to the prices paid in our top five trading partners. That would show trading partners that New Zealand is doing its bit, be administratively simple, be politically durable, and most of all, effective."