A new Kiwi study has found no matter how efficiently New Zealand produces meat, cutting back is still the best way to fight climate change. 

University of Otago researchers looked into the food industry's impact on climate change and greenhouse gas emissions. Senior author Alex MacMillan says they found no evidence that we are being much more sustainable than anyone else.

"That is a surprise, because we're told all the time by the industry that we're a low-emissions producer of meat and dairy."

The study, published in journal Environmental Health Perspectives, ranked New Zealand's beef and lamb production as more efficient than the global average (emitting 21kg and 17kg of carbon dioxide per kilogram of meat, respectively, compared to a world average of  27kg and 26kg.) 

But the average Kiwi adult's diet was overall no better for the climate, with the typical emissions "broadly in line with estimates from around Europe".

"Our analysis showed that the potential for achieving diet-related emissions reductions is primarily determined by the type and quantity of meat consumed," the study reads, backing up claims made in a controversial climate change teaching resource being rolled out to schools this year. 

The study also found that people think it's better to buy locally-grown food. But Dr Alex MacMillan says this is no longer necessarily the case, with transport costs only making up a small proportion of emissions.

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"From a climate pollution perspective, it doesn't matter where you get your plant-based food from. It's always better to choose a plant-based food rather than meat, regardless of where it was grown."

Their findings back up a UK study from 2018, which researchers said proved a "vegan diet is probably the single biggest way to reduce your impact on planet Earth".

If every Kiwi adult switched to a plant-based diet, the researchers behind the latest study say it would be the equivalent of a 59 percent reduction in car emissions, as it takes a lot more resources to produce meat than plants.

It could also save up to $20 billion in health costs over the lifetime of the current New Zealand population. 

"Fortunately, foods that are health-promoting tend also to be those that are climate-friendly," said Dr MacMillan.

"Conversely, certain foods that carry known health risks are particularly climate-polluting. Red and processed meat intake, for instance, is associated with an increased risk of cardiovascular disease, type-2 diabetes and certain cancers."

A spokesperson for Beef+Lamb NZ told NZME the study was "unfair" and "overly simplistic", saying most land used in New Zealand would be unsuitable for producing plant-based foods.

And before you go claiming it's impossible to live on a vegan diet, Dr MacMillan says the adult diet they based the research on meets New Zealand guidelines.

"As our modelled dietary scenarios became increasingly plant-based and therefore more climate-friendly, we found that associated population-level health gains and healthcare cost savings tended also to increase. 

"A scenario that replaced all meat, seafood, eggs, and dairy products with plant-based alternatives, and that also required people to cut out all unnecessary household food waste, was found to offer the greatest benefit."

A spokesperson for Beef+Lamb NZ told NZME the study was "unfair" and "overly simplistic", saying most land used in New Zealand would be unsuitable for producing plant-based foods.

Beef and lamb were singled out by the researchers as the most emissions-intensive foods, followed by processed meats, pork, shellfish, butter and cheese. Further back were fish, eggs, poultry and yoghurt, followed by processed foods (cookes, ice cream, pies, soft drinks), nuts and rice, then at the bottom, plant foods.

A new resource being rolled out for teachers to help them teach climate change this year angered many with its advice to "eat less meat and dairy" to help reduce emissions. NZ First -  partner in the present Government - even said getting rid of the meat industry could result in half the country becoming unemployed. 

National - popular amongst farmers - has suggested it might alter or withdraw the voluntary resource if it wins the election later this year.