The Greens had already made substantial commitments on climate change, including passing a UK-style "Zero Carbon Act" to set binding targets on a downward path towards carbon neutrality by 2050 in their first hundred days, and a green infrastructure fund to help shift the economy in a sustainable direction. Now they've added to that, with a proposal to replace the Emissions Trading Scheme with a "Kiwi Climate Fund" - effectively a carbon tax with variable rates for different gases, allowing a transition for farm emissions.
The problem with the ETS is that while its perfect in theory, its absolutely ineffective in practice. Labour weakened it with subsidies, National weakened it further, and meanwhile international trading flooded the market with fraudulent "credits" that had no environmental value at all. This crashed the price, providing no incentive for anyone to reduce emissions. The Greens' plan would replace all that with a simple tax regime, with the revenue recycled into emissions reductions and a universal payment to every adult New Zealander. Forest-owners would get a fixed payment, rather than the present credit scheme. While unstated, I expect that the proposed independent climate change commission would recommend tax increases to reduce emissions over time.
In theory, this is equivalent to an ETS. In practice, it is likely to be easier to administer and more effective. There will be transition costs - the ETS will take some time to unwind. So its really a way of putting pressure on pro-ETS parties to fix the fucking thing: bring in agriculture, stop subsidising pollution, strangle credit supply to hike the price, so that it works as it should. Otherwise we're just shuffling paper around as a substitute for action.
The other big part of the Greens' proposal is a commitment for no new coal, no fracking, and no new deep sea oil. Which makes sense: the fossil fuel industry is the problem, and they have no future if we are to survive as a civilisation. We need to admit that, and put them out of business (or at least reduce them to the handful of uses for which there aren't substitutes). The market is already doing a lot of this for us (the global coal industry is going bankrupt ATM), but we need to draw a line under it. A "no new holes" policy is a good way of doing this.
Labour is talking big on climate change. I guess now we get to see whether they're serious or not.