What should we eat if we want to reduce levels of greenhouse gases that contribute to global warming?
Meat is the answer that usually grabs the headlines. If we could stick with the modest intake of meat recommended in dietary guidelines* around the world, we’d slash food-related greenhouse gas emissions by almost one-third was the verdict from Oxford University researchers in the UK last year.
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But our appetite for red meat isn’t the only problem. There’s the highly processed foods like salty snack foods, pies, cakes, soft drinks, sweets and processed meats that also add to the burden of greenhouse gases but without doing anything for our health – unless you count their contribution to chronic disease.
These foods make up a big slice of the nation’s diet. Around 35 per cent of the average Australian’s kilojoule intake comes from these products which, along with alcohol, are known as “discretionary foods” because they’re not essential for health.
What you choose to put on your fork can make a difference to the environment. Photo: Stocksy
“If we could reduce discretionary food and eat according to dietary guidelines, greenhouse gases would be 12 per cent lower in Australia – it’s a win-win for the environment and for our health,” says Dr Brad Ridoutt, Principal Research Scientist with CSIRO Agriculture.
“When we assessed more than 9000 Australian adult diets last year the differences in GHG emissions were staggering – the diets that were healthiest and produced the least GHG emissions had 45 per cent fewer GHG emissions than the poorest diets with the highest emissions – and the outstanding difference was excessive consumption of discretionary foods in the poorer diets.”
“Although meat is the main contributor to food-related greenhouse gas emissions, the production of processed food uses high amounts of fossil fuel. When you eat a diet that’s high in these foods you’re not only contributing to poor health you’re also contributing to climate change,” adds Dr Gary Sacks, Senior Research Fellow at the Global Obesity Centre at Deakin University.
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“We need a strong public health message that communicates the link between what we eat and our own health and that of the planet.”
But some countries, including Brazil, Sweden, Germany and Qatar, have already joined the dots with guidelines promoting healthy diets with a low environmental impact. What they have in common according to Plates, Pyramids, Planet, a report by the Food Climate Research Network based at Oxford University is to eat: a diet based on minimally processed wholegrains, legumes, fruit and vegetables; meat, if eaten, in moderation and including all animal parts; moderate amounts of dairy (or alternatives like fortified milk substitutes or other calcium rich foods); unsalted nuts and seeds; small quantities of fish from certified fisheries; oils and fats with a beneficial omega-3-6 ratios such as olive oil or rapeseed; very limited consumption of foods high in fat, sugar or salt and low in micronutrients e.g. crisps, confectionery, sugary drinks. Sweden’s guidelines also add some interesting details – like a pack of jellybeans has as big a climate footprint as a small piece of pork.
And while your paleo friends might not approve, legumes (like beans, lentils and chickpeas) are the food world’s superheroes in the fight against climate change. Besides delivering protein with fewer GHG emissions than meat, they also make their own fertiliser by plucking nitrogen from the air and (with a little help from soil microbes) turn it into plant food.
The beauty of this is that it reduces the need for synthetic nitrogen fertiliser – which generates high levels of CO2 [carbon dioxide] when it’s produced, explains Associate Professor Brent Kaiser who heads Legumes for Sustainable Agriculture, a new research hub at the University of Sydney devoted to increasing Australia’s legume production and making them more of an Australian staple.
“People want a choice of where their protein comes from and legumes provide protein sustainably without going through animals – but they also provide more efficient animal feed because, unlike cereal crops, they don’t need nitrogen fertiliser to grow,” he says.
Swapping meat for legumes in some meals is also a win for human health – studies have linked them to a lower risk of heart disease, diabetes, cancer and obesity.
What about the argument that cutting back on meat is futile if other countries in Asia, for example, are eating more?
Even China is taking action, points out Mark Pershin, founder of Less Meat, Less Heat the non-profit organisation that works to shift attitudes towards meat eating for the climate’s sake and which created the Climatarian Challenge app that challenges you eat a carbon conscious diet for 30 days.
Last year China produced dietary guidelines encouraging people to eat less meat – and the Chinese Nutrition Society even enlisted the help of Arnold Schwarzenegger in this worth-a-look clip highlighting the link between climate change and food.
“It’s up to countries like ours to lead the way,” Pershin says. “Trends spread around the world rapidly, and often start in Australia – why not show the rest of the world that low-carbon, climatarian food can be good for us and good for the planet. “
*Dietary Guidelines for Australia recommend around 455g cooked lean red meat weekly