Agriculture would be given a five year window before being required to significantly cut emissions under a Green Party climate plan.
That would remove the Government's "main road block" to action on climate change and ensure farmers did their fair share, the party says.
The plan would also require 100 per cent renewable electricity generation should by 2030, and an immediate tree-planting programme, among other measures.
"Our climate plan shows how, with real leadership and a bit of Kiwi ingenuity, the Government can reduce our emissions by a respectable 40 per cent below 1990 levels," co-leader James Shaw said, at the launch of the 'Yes we can!' climate plan in Wellington today.
New Zealand needed to face-down the "terrifying truth" of climate change, Mr Shaw said, and not take the easy but futile option of "blocking our ears and covering our eyes".
"Coastlines, in places like Haumoana in Hawkes Bay are disappearing. Previously fertile pastures are drying up, one in 100 year floods are happening every year in places like Dunedin and Whanganui, and species are falling into extinction every day."
Under the Greens' plan the 40 per cent target would be achieved by:
• The establishment of a Climate Commission to assess the Government's progress on meeting targets, and that would provide advice on improvements.
• A Green Investment Bank to stimulate growth in low-emission economic activity.
• A "Climate Tax Cut" that would put a price on greenhouse gas emissions, but recycles the revenue back to householders and business through tax credits.
Mr Shaw said that the Government also needed to implement policies to reduce emissions in electricity, transport, industry, waste and forestry.
For example, 100 per cent renewable electricity generation should be achieved by 2030, in part through initiatives such as smart grid technologies and wider use of solar panels.
In Agriculture, after a five year lead-in time agriculture would need to reduce its emissions by 2.2 Mt below 2015 levels by 2030.
All of the cuts outlined in the climate plan would achieve a target of 35 per cent below 1990 levels by 2030, the Greens said, and an immediate tree-planting regime would ensure the 40 per cent target was met.
In July, Minister for Climate Change Issues Tim Groser confirmed a higher emissions reduction target, that would be to reduce greenhouse gas emissions by 30 per cent from 2005 levels by 2030.
He described it as a "significant increase" on the 2020 target, which was a reduction of 5 per cent below 1990 levels. If the new target was set to a 1990 baseline, it was the equivalent of an 11 per cent reduction.
Emissions targets which were set under the Kyoto agreement were due to expire in 2020. All countries were now expected to set new targets for the period after 2020 as part of a climate change agreement to be concluded in Paris.
Labour and Greens wanted Government to match the EU by setting a target of at least a 40 per cent reduction on 1990 levels by 2030.
The Government has said it needed to ensure the target was achievable and avoided imposing unfair costs on any particular sector or group of people.
Mr Shaw said the Government's target was "one of the world's weakest and most embarrassing", and others such as the European Union had pledged targets of 40 per cent below 1990 levels by 2030.