Researchers have estimated greenhouse gas emissions from the food sector could rise by 80% by 2050, as the world increasingly adopts meat-based diets that are putting resources and food security at risk.
A new study by the universities of Cambridge and Aberdeen has warned that the global population must switch to a diet that includes less meat and dairy in order to avoid a devastating rise in greenhouse gas emissions from the food sector. It is the latest of a number of studies putting meat consumption under scrutiny.
Based on current projections, researchers have said that by 2050 – when the global population will reach 9.6 billion – croplands will have expanded by 42% and fertiliser use increased by 45% over 2009 levels, with deforestation also getting worse.
This would be largely due to food waste and unsustainable diets, where animal products play a crucial role. Livestock is largely responsible for agriculture’s use of natural resources such as water, land and crops. This is a major contributor to climate change and deforestation, especially in Latin America where large parts of forest are cleared to grow animal feed.
Bojana Bajzelj from the University of Cambridge’s Department of Engineering, one of the authors of the research, said, “There are basic laws of biophysics that we cannot evade. The average efficiency of livestock converting plant feed to meat is less than 3%, and as we eat more meat, more arable cultivation is turned over to producing feedstock for animals that provide meat for humans.
“The losses at each stage are large, and as humans globally eat more and more meat, conversion from plants to food becomes less and less efficient, driving agricultural expansion and land cover conversion, and releasing more greenhouse gases. Agricultural practices are not necessarily at fault here – but our choice of food is”.
According to the Vegan Society, a plant-based diet requires only one third of the land needed to support a meat and dairy diet. As more developing countries adopt Western-style diets, the problem only looks set to get worse.
The study suggests three measures to avoid a rising emissions scenario; halving food waste, adopting a less meat-based diet and closing ‘yield gaps’ – gaps between crop yields achieved in best practice farming and the actual average yields.
These three steps would halve greenhouse gas emissions levels from those of 2009, the study argues.
Co-author Prof Keith Richards added, “This is not a radical vegetarian argument; it is an argument about eating meat in sensible amounts as part of healthy, balanced diets.”
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