Professor John Craig, former dean of science at the University of Auckland, says native trees are our best carbon stores.
Farming is commonly called a major driver of climate change.
Agriculture in Northland accounts for 41 per cent of the regional emissions, only topped by goods production with 45 per cent.
While food production is essential for our economy this carbon footprint can be reduced and better understood with the right policies, impulse and research.
NorthTec business management lecturer Peter Bruce-Iri has recently co-written a report for Unesco explaining how mātauranga Māori and Western science can protect and restore the soil on rural farms in Te Tai Tokerau and says: "Farming done properly can reduce emissions significantly."
To understand how we have to look at the soil.
Soil doesn't only provide pasture for animals it also serves as an indicator for the health of the ecosystem of a farm.
After early settlers cleared most of New Zealand's bush, the soil was highly fertile but agriculture reduced that fertility so farmers looked at ways to replenish it and introduced artificial fertilisers.
Artificial fertilisers along with herbicides and pesticides have become entrenched with farming techniques; however, their use entails several downsides, including reduced animal health and increased greenhouse gas emission.
"We've started farming in ways that are not respectful of nature," Bruce-Iri said.
But nature provides us with solutions.
An emerging farming method – regenerative agriculture (RA) – focuses on rehabilitating the ecosystem of farms, increasing its biodiversity and producing nutrient-dense food while also providing farmers with good livelihoods.
RA first cropped up in the 1980s but only took off in the past decade.
Forerunner organic farming had brought the idea of sustainable farming into the mainstream but some experts say it reached a dead end because of limiting regulations.
RA, on the other hand, doesn't detail what methods have to be followed leaving room for development. Critics will say the lack of clear guidelines makes it too unreliable.
"When you get it right there is a cascade of benefits."
Bruce-Iri says presenting your animals with a diverse, nutrient-dense pasture is like opening the doors to a pharmacy where the animals can choose what they need.
Improved infiltration, drainage and retention of water will make the farm more resilient to drought and heavy rainfall events – both expected to increase in Northland.
Bruce-Iri explained that by becoming regenerative, farmers often started off by reducing their stock numbers which meant an initial income decrease.
But because RA reduces running costs from vet visits, sprays and other supplements it becomes profitable.
"And it puts the joy back into farming," Bruce-Iri said in reference to high suicide rates within the rural community.
Matapōuri dairy farmer Matt Long and his family made the shift a decade ago and are not looking back.
"We've stopped using artificial nitrogen and moved to more natural fertilisers and a more natural way of looking after the animals," Long said.
After being into it for more than 10 years, Long takes the "ease of things" such as improved animal health for granted.
Cutting synthetic nitrogen, which when sprayed joins oxygen and enters the atmosphere as a potent greenhouse gas, has improved the health of his soil, plants and animals.
"The quality of the feed is higher and we're paying more attention to the animals by supplementing them with minerals and vitamins. We're also concentrating on making the pastures as healthy as we can," Long said.
"In a traditional farm where they're using a lot of artificial nitrogen and superphosphate, it tends to unbalance the animals' systems.
"They get what's called metabolic diseases which are caused by a shortage of calcium and magnesium. And another thing called bloke which is when their feed froths up in their stomach until they can't breathe any more.
"You don't get those under a more natural fertiliser system."
Instead, Long is using mineral and microbial inputs to keep his land green. He has also drastically reduced the use of herbicides meaning micro-organisms in the soil flourish.
"The soil around the root of the plant is like a stomach – it's how the plant digests and gets its nutrients. Fungi increase the root area for the plant. They have a symbiotic relationship."
Long said alternatives to superphosphate and nitrogen are easily accessible in New Zealand.
In terms of productivity, Long said his return on investment was "fairly good".
Long said his motivation to switch to a low-impact farming system stems from a moral conviction to farm with healthier, happier animals, healthier food for people and healthier outcome for the environment.
"Most farmers think that, too," Long said. "It's just that they are caught up in their traditional mindset."
The family farm is also measuring the carbon content of its soil which can be complex because soil and its inhabitants are diverse and dynamic.
That's why the carbon sequestration potential of soil is still contested.
Carbon is both the catalyst and essential ingredient of soil formation. Regenerative farms, like Long's, have been shown to sequester more carbon compared to traditional farms.
Meanwhile, carbon-depleted soil is more prone to erosion and can't sustain diverse plant and micro-organism life.
The soil carbon science is relevant for Northland considering there are 735,400ha of pasture, more than half the region's 1.42m ha, and its sequestration potential is not taken into account when we look at agricultural emissions.
This Ministry of Primary Industries (MPI), however, is taking interest in how much carbon is sequestered by vegetation.
Forty-one per cent or 594,390ha of Northland is covered in vegetation, including 187,550ha of exotic forest, 268,740ha of native forest, 125,280ha of shrubland and 12,820ha of mangroves.
Under the Emissions Trading Scheme (ETS), New Zealand's official tool for measuring and billing greenhouse gases which is also used internationally, MPI is looking at carbon sequestration through vegetation.
Landowners, businesses or organisations involved in ETS can earn credits for activities that absorb carbon dioxide, such as managing or planting trees. They can then trade their ETS credits or use them to offset their greenhouse gasses.
John Craig, former professor of environmental management at the University of Auckland and biodiversity adviser for Pataua-based beekeeping business Tahi, says "unfortunately" the ETS is built around pine trees and sidelines natives.
"The heavier the wood, the more carbon it will have in it," Craig explained.
"If you take a native tree, like puriri, it's very hard and heavy and it's one of our best carbon stores.
"Whereas if you take a pine tree it grows faster initially, but it's soft, light wood and it burns quickly and doesn't give you a lot of heat, so it doesn't have a lot of carbon in it."
ETS credits can be claimed for native trees under MPI regulations but Craig estimates it's only a third of what they are worth in terms of carbon sequestration.
Tahi's ecologist, Neil Mitchell, is researching how much carbon native trees are sequestering and he has found that after 22 years of growth natives are storing carbon faster than pine trees.
"The ETS totally ignores that," Craig said.
Tahi and other parties have been in consultation with MPI and are hoping for an overhaul that will focus more on carbon sequestration of endemic rather than exotic vegetation.
At the moment, it doesn't pay off for small businesses like Tahi to claim ETS credits even though they planted 349,000 native trees and are looking after 360ha of land.
Changes to the ETS could provide extra income for sustainable business and incentivise more the planting of native bush.
Farmer Matt Long also hopes that carbon sequestration of his soil will eventually be recognised so his family can claim credits.
Meanwhile, Bruce-Iri is already thinking a step ahead: He has been looking at methane and how pastures can function as methane sinks.
Bacteria in the soil are part of a natural process that breaks down this potent greenhouse gas – another advantage of regenerative farming with its healthy soils.
Bruce-Iri would like to see the Government push for a shift towards regenerative farming.
To create lasting change, the shift required solid policy but also an individual choice: "People have to question their own assumptions about how the world works.
"Within the natural world, including the way we grow our food – that is where the biggest gains are to be made."
The series
Friday: How to encourage climate action
Monday: Niwa scientists predict Northland's climate
Tuesday: How can we help?
Wednesday: What are our councils doing?
Thursday: How we can fight for climate justice
Yesterday: How to take industry into a sustainable future
Today: Regenerative farming and growing techniques
Monday: The future generation
The latest news bites from around the region.