Global Warming: Current Food Systems May Push Temperatures Beyond Threshold Without Fossil Fuels

The world's current food systems could push global temperatures beyond the warming threshold of 2 degrees Celsius set in the Paris Agreement, even if fossil fuel emissions ended today, according to a study.

Global food systems are driving twin crises of obesity -- by promoting high-calories, low-fibre products including ultra-processed foods -- and climate change, an international team of researchers from the UK, US, Australia and Singapore said.

Reviewing recent evidence from epidemiology and endocrinology, among others, the study published in the journal 'Frontiers in Science' highlights how tackling unsustainable, profit-led food systems is urgent for both health and climate.

While weight-loss drugs and surgery are options for individuals with obesity, they fail to address the wider environment affecting whole populations and ecosystems, the authors added.

They also pointed to concerns over long-term affordability, safety and sustained global access to the treatments, especially as obesity increasingly affects younger and lower-income populations.

"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," lead researcher Jeff Holly, from the UK's University of Bristol, said.

"Unlike weight loss drugs or surgery, addressing this driver will help humans and planet alike," Holly said.

The authors recommend subsidies for healthy foods, taxes and warning labels for particularly unhealthy foods, and restrictions on an aggressive marketing of high-calorie, low-fibre products, particularly in low-income communities and to children.

By 2035, half the world's population is projected to be overweight or obese -- conditions that increase risks of chronic, non-communicable diseases, including heart disease and cancer, the team said.

They added that global warming now kills one person every minute around the world, accounting for around 5,46,000 deaths per year over the period 2012-2021, up 63% from the 1990s.

Food production was found to be responsible for between a quarter and third of total greenhouse gas emissions, and the leading cause of land clearance -- said to drive deforestation and biodiversity loss.

"Even if all fossil fuel emissions were halted immediately, the current food system on its own could be enough to breach 1.5 (degrees Celsius) and potentially 2 (degrees Celsius) climate target," the authors wrote.

First author Paul Behrens, from the UK's University of Oxford, said, "We can't solve the climate crisis without transforming what we eat and how we produce it."

"To tackle the climate crisis, we must tackle food systems that push up emissions and push us toward energy-dense and highly processed diets full of animal products," Behrens said.

The researchers also suggested shifting diets toward minimally processed, fibre-rich plant foods and fewer animal products.

Preventing weight gain through healthier food environments would be 'less harmful and much cheaper' than adapting to the consequences of both obesity and climate change, or treating individuals instead of changing systems, they said.

Obesity-related expenses cost over two per cent of the global GDP in 2019 -- these are projected to exceed four trillion dollars by 2035, if trends continue, the team said.