Global food systems alone could drive Earth’s temperature beyond the critical 2 degrees Celsius warming limit set under the Paris Agreement, even if all fossil fuel emissions were stopped immediately, according to a new international study.
The research, published in the journal Frontiers in Science, warns that today’s profit-driven and unsustainable food systems are fuelling a dual global crisis—rising obesity rates and accelerating climate change. The study was conducted by researchers from the UK, US, Australia, and Singapore, drawing evidence from fields including epidemiology and endocrinology.
Food systems that promote high-calorie, low-fibre, and ultra-processed foods are contributing significantly to greenhouse gas emissions while also increasing the prevalence of obesity worldwide, the researchers said. By 2035, nearly half of the global population is projected to be overweight or obese, increasing the risk of chronic non-communicable diseases such as heart disease and cancer.
“While obesity is a complex disease driven by many interacting factors, the primary driver is the consumption-driven transformation of the food system over the last 40 years,” said lead researcher Jeff Holly from the University of Bristol. “Unlike weight-loss drugs or surgery, addressing this driver will help humans and the planet alike.”
The study highlights that food production accounts for between one-quarter and one-third of global greenhouse gas emissions and is the leading cause of land clearance, deforestation, and biodiversity loss. The authors warned that even without fossil fuel emissions, current food systems could still breach the 1.5°C and potentially the 2°C climate targets.
First author Paul Behrens from the University of Oxford stressed that climate action cannot succeed without food system reform. “We can’t solve the climate crisis without transforming what we eat and how we produce it,” he said, calling for a shift toward fibre-rich, minimally processed plant-based foods and reduced consumption of animal products.
The researchers recommended policy measures such as subsidies for healthy foods, taxes and warning labels for unhealthy products, and stricter regulations on aggressive marketing of high-calorie foods, particularly to children and low-income communities.
They also raised concerns about relying on weight-loss drugs and surgery, citing issues related to affordability, safety, and long-term global access. Addressing unhealthy food environments, the study said, would be less harmful and far more cost-effective than treating obesity or adapting to climate-related consequences.
Global warming is already estimated to cause one death every minute worldwide—around 546,000 deaths annually between 2012 and 2021—while obesity-related costs exceeded 2 per cent of global GDP in 2019 and are projected to surpass USD 4 trillion by 2035 if current trends continue.
