The climate impact of going vegan for two years is the equivalent of one transatlantic flight per passenger - meaning "eating our way out of climate change" would not have a major impact on climate action, according to US scientist Dr. Frank Mitloehner.

However, a prioritisation of tackling food waste both at national and international level would have a far greater impact, the professor stressed.

Dr. Mitloehner – a professor and air-quality specialist in the Department of Animal Science at the University of California, Davis, commented on the matter in a presentation made at last week’s online Alltech Ireland Environment Forum.

"Sometimes people say ‘maybe we can eat our way out of climate change’. I’m sure you’ve heard this discussion before," the scientist told attendees of the virtual event.

"There are campaigns all over the world telling people to go plant-based, away from animal-sourced foods.

"I looked at some of the more recent literature on this topic and one paper in particular [Wynes and Nicholas, 2017] looked into how different lifestyle choices affect our greenhouse gas emissions.

"Contrast that to another activity so that you have something to relate it to, one transatlantic flight per passenger causes 1.6t of CO2 eq. – meaning if you go vegan for two years, then the impact that has on climate equals one single transatlantic flight per passenger."

Pointing to this as a reference point, the specialist continued, stating:

"Here in the US some people say we should do ‘Meatless Monday’ where we eat less meat in the week. What if the entire US were to do that? We would reduce our carbon footprint by 0.3%.

"If it’s not happening here, it wouldn’t happen in much of the rest of the developed world," he argued.

Turning to "what within our food system has the biggest impact on climate or environmental harm", Dr. Mitloehner highlighted that "40% of all food we produce in the US, we produce in all developed countries – and even in developing countries – goes to waste".

"But even globally, the number holds true that close to 40% of all food humanity produces goes to waste," he warned.

"I think we can do much better here - and that’s true for all countries including yours.

"A focus on food waste would be really timely right now, it’s paramount that we deal with this," the specialist concluded.