The need to cut food’s climate emissions

Te Whanganui a Tara - Food is increasingly high on the menu when it comes to climate concerns. As the world's population rises, the impact of food on the climate is soaring. New Zealanders need to think carefully about what they buy and eat.

Fuelled by resource-draining practices and our increasing demand for environmentally-damaging meat, what people eat has never mattered more to the planet's health, Sarah Bridle, a physics department professor at the University of Manchester in the UK says.

She uses data science to study food production which contributes more than one-quarter of all climate change-causing emissions, when taking in all the steps it takes to get food from field to plate.

This includes clearing land to make space for agriculture, making and applying fertilisers, rearing animals and processing, packing and transporting the end result to consumers.

As climate change continues, the amount of food produced from each patch of land is forecast to change and on average it is expected to go down.

That means less food for a rising population. At the same time, an increasing number of extreme weather events due to climate change, from droughts to flooding and storms, will devastate or reduce the size of a crop.

But it is possible to slow these changes through the food people choose to eat. Not all foods are equal when it comes to causing climate change.

Research shows that people are generally not aware of how big the differences are and will underestimate their food's emissions. Consider two different dinner options: an 227g steak with fries and a microwaved potato with beans. The steak dinner is more than 20 times worse for the climate than the beans dinner, even after considering cooking.

Explaining this discrepancy between people's estimates of emissions and the true figure is something Professor Bridle understands.

“I find people are usually surprised by the size of the difference between steak and beans, until I explain that about five percent of the calories eaten by a cow are burped out again as methane, which is a powerful greenhouse gas.”

Even a partial substitution can have a big impact. A 227g piece of steak contains 100 percent of the recommended daily intake of protein. Meat eaters should switch to a half size piece of steak and supplement a diet with a few beans, nuts, fish or dairy.

People have got used to having seasonal vegetables on-hand all year round. But when eating out-of-season vegetables and fruit it adds air miles to the diet.

But how important is it to eat vegetables that are local and in season, rather than transporting some asparagus or green beans from another continent?

Air freight causes 100 times the climate impact of transporting the same amount of food by boat. With fast growing plant-based meat alternatives now sold in supermarkets, the accessibility of more sustainable foods has never been better.

The system that should be introduced to help reduce the impact of food on climate change is transparency. Air-freighted fruit for example should have a sticker on all the food that came by air.

Labelling can help address the lack of consumer awareness about food climate impacts. Some of this is starting to happen already, with the food brands such as Quorn showing the emissions for each of their products on their packages.

Denmark has recently announced that it will mandate food climate labelling and issued dietary guidelines specifically addressing climate impacts, including recommending eating less meat and more plants. What is Aotearoa doing?

Finally, food waste is bad. Globally, about a third of food is lost or wasted. Reducing food waste avoids causing the climate impacts of the wasted food and sending less food to rot and release methane at landfill sites.