Fonterra supports the Government's Zero Carbon bill but is urging a cross-party approach on the legislation, MPs considering the bill have heard.

And it wants the 2050 biogenic methane target set at 24 per cent less than 2017 levels – the low end of the current range set out in the bill.

One of the MPs considering the bill, Green MP Chloe Swarbrick, thanked Fonterra for their "leadership in this space".

Fonterra's dairy business is responsible for 20 per cent of New Zealand's gross greenhouse gas emissions, managing director of co-operative affairs Mike Cronin told the environment select committee.

"Fonterra supports the Climate Change Response (Zero Carbon) Amendment Bill because it will create a framework and institutional arrangements that will keep New Zealand on track to mitigate and adapt to climate change," Fonterra's submission said.

"The legislation strikes a balance between flexibility and prescription in New Zealand's long-term transition.

"A cross-party approach to this critical issue will provide New Zealanders with clarity about the pathway ahead, and give our farmers time to adjust and adapt their businesses."

However it also said that the 2030 and 2050 methane targets were "ambitious and will be a challenge to achieve".

Cronin said farmers knew change was needed but the targets needs to be based on what was scientifically possible and what was economically viable.

He said Fonterra recognised the work across political parties that had been put into the legislation.

"And we strongly encourage the committee to seek a political consensus going forward.

"If farmers are changing farming systems and investing in new products, they need certainty that the targets are not going to suddenly and radically change."

The bill is part of the Government's response to the Paris Agreement 2015 to limit global warming to no more than 1.5 degrees Celsius above pre-industrial levels.

The bill sets out targets for emission reductions:

• Zero net emissions of greenhouse gases by 2050, other than biogenic methane (from animals and waste);

• Gross emissions of biogenic methane to be 10 per cent less than 2017 levels by 2030, and at least 24 per cent to 47 per cent less than 2017 levels by 2050 and beyond.

That range is expected to be narrowed at some point and possibly changed to a single figure target but when it not determined.

That select committee could recommend a change in the range in its report back.

The bill also provides for the establishment of an independent Climate Change Commission and for the commission to review the 2050 target on or after 2036, allowing for a new timeframe or level of emissions reductions required.

Fonterra's Andrew Kempson also said that from the end of the current season it would be providing all of its farmers with a bespoke unique report telling them about their farm's emissions.

"We want to support farmers to be able to understand their numbers because that awareness will help us a long way in terms of appreciating their impact and the risks as well.

Fonterra is a co-operative owned by about 10,000 farming families.

It employs about 20,000 people, most in New Zealand.

It runs 33 manufacturing plants and has a significant transport fleet.

Green MP Chloe Swarbrick thanked the Fonterra submitters for their" leadership in this space."

"It has been incredibly important."

Fonterra is a co-operative owned by about 10,000 farming families. It employs about 20,000 people, most in New Zealand. It runs 33 manufacturing plants and has a significant transport fleet.

The Climate Leaders' Coalition, a group of 110 chief executives, also called for a bipartisan approach in its submission today.

Neal Barclay, the chief executive of Meridian Energy, said it was time to "collectively stop admiring the problem and move to action, and action soon."

"Political consensus is the key and a politically and financially independent climate commission is critical to providing that objective advice on emissions targets and budgets."

Malcolm Johns, chief executive officer of Christchurch airport, said bipartisanship was needed to avoid what had happened in Australia.

"You don't have a pathway over time. Nobody could see how their lives fit into 2030 and 2050 in Australia. That's why you need bipartisanship. That's why you need a long-term framework . It's absolutely critical.

Climate Change Minister and Green Party co-leader James Shaw developed much of the bill in co-operation with National leader Simon Bridges and former climate change spokesman Todd Muller.

National voted for the first reading but opposed the methane targets and has not decided whether it will continue to support it.