The global food system must be radically redesigned if the world is to escape global warming, scientists warn in a new report.

In a paper published in the journal Science, the authors point out that while a great deal of attention has been paid to reducing fossil-fuel emissions, little has been done with agricultural practices. They contend that even if fossil fuels were completely eliminated, current agriculture practices alone will bring the world close to a rise of 1.5°C above preindustrial levels – one of the upper limits specified in the Paris Agreement. With realistic levels of fossil fuel consumption, the world might reach 2°C above preindustrial levels, which would lead to irreversible climate change, in the opinion of many climate scientists.

"All it would take for us to exceed the two-degree warming limit is for food emissions to remain on their path and one additional year of current fossil fuel emissions," said David Tilman, a professor of ecology at the University of California at Santa Barbara. "And I guarantee you, were not going to stop fossil fuel emissions in a year."

The problem, as the authors see it, is present at all economic levels. Affluent, developed nations raise greenhouse gas emissions through meat production and heavy use of fertilizer. In less affluent countries, demand for food often is met by deforestation and other land clearing.

The authors suggest solutions such as deemphasizing meat in favor of plant-based foods, using fertilizer more efficiently, increasing yields and reducing food waste.