Gen Alpha and Gen Z are individually responsible for the highest food-related climate emissions of any age group, according to new research examining diets around the world.
An international team of researchers analysed diets across 149 countries and 22 distinct age groups, using data collected between 2000 and 2019. They found that Gen Alpha, aged 0 to 16, and Gen Z, aged 16 to 29, drive the highest climate emissions of any generation through their diets.
The researchers say the trend is being driven by these groups eating more meat, dairy, processed foods and sugary drinks. They warn the rising emissions are also linked to worsening diets, creating what they call a 'dual crisis' of poor nutrition and accelerating climate change.
Co-author Professor Yuli Shan, from the University of Birmingham, said the finding challenges 'the dominant narrative that older populations are the most carbon-intensive consumers.' Shan added that the result 'prompts policymakers to face some tough challenges' in bringing rising emissions under control.
How food systems drive emissions
Global food systems currently produce about a third of the world's total greenhouse gas emissions. These come from deforestation used to clear land for farming, methane released by cattle, byproducts of synthetic fertilisers, and the fuel needed to ship food around the world.
The researchers found that different age groups contribute very differently to this total footprint.
Elderly drive the fastest emissions growth
As a group, people aged 60 and over produce the most dietary greenhouse gas emissions overall. Global dietary emissions rose by 2.1 billion tonnes of CO2 between 2000 and 2019, and seniors contributed more than a quarter of that increase.
In high-income regions such as Japan, the United States and western Europe, older adults now account for 22 to 29 per cent of total food-related emissions. Researchers say this is not because seniors' diets are worse for the environment, but because the population of elderly people is growing rapidly, making them the fastest-growing contributors to dietary emissions.
Young people's diets still worse per person
Even so, the diets of young people produce more greenhouse gas emissions per capita than those of older people.
The researchers say this is mainly driven by young people eating more animal products, especially red meat. Studies suggest Gen Alpha is more open to meat-free or 'flexitarian' diets: in one study, nearly half of 1,000 young adults in the UK said they had considered giving up meat, and more than half of those had actually ditched meat for a period of time.
Even so, globally, young people still tend to eat more meat than their older counterparts, and the amounts they eat are increasing.
Meat consumption and emissions
Research shows that diets high in meat are associated with significantly higher greenhouse gas emissions than plant-based alternatives. One recent study found that eating just 100 grams of meat a day, less than a single burger, creates four times more greenhouse gases than a vegan diet. The same study found the dietary impact of vegans on greenhouse gas emissions was just 25 per cent of that of high meat-eaters.
A nutrition versus emissions dilemma
In high-income countries, the shift toward more meat and animal products is associated with poorer nutrition. But in lower-income countries, the picture is more complicated: increases in emissions there have often occurred alongside improvements in nutritional quality.
Co-author Professor Klaus Hubacek, from the University of Groningen, said: 'In many low- and middle-income countries, increases in emissions have occurred alongside improvements in nutritional quality, meaning that simply reducing certain types of food may have unintended health effects.'
Part of the emissions increase in low-income countries also simply comes from young people eating more food overall, the researchers said.
The researchers describe this as a 'growing dilemma' for policymakers: how to reduce emissions without undermining improvements in nutrition. They suggest policymakers should prioritise education and behavioural change, reform school and youth food environments, and balance environmental considerations against nutritional needs.
