A shift to healthier diets is one of a number of global actions that need to be taken to avoid dangerous climate change and ensure there is enough food for all according to university researchers from Cambridge and Aberdeen.
If current trends continue, food production alone will reach, if not exceed, the global targets for total greenhouse gas (GHG) emissions in 2050, it was concluded by researchers from the University of Cambridge’s Department of Engineering and Department of Geography and Plant Sciences, as well as the University of Aberdeen’s Institute of Biological and Environmental Sciences.
Their report stated that as populations rise and global tastes shift towards meat-heavy Western diets, increasing agricultural yields will not meet the projected food demands of what is expected to be 9.6bn people, making it necessary to bring more land into cultivation.
This will come with a high price, they warned, claiming that if we maintain “business as usual” then by 2050 cropping land will have expanded by 42% and fertiliser use increased by 45% over 2009 levels.
“There are basic laws of biophysics that we cannot evade,” said lead researcher Bojana Bajzelj.
“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.”
They also said, however, that it was not agricultural practices which were necessarily at fault here, but rather our choice of food.
The average’ balanced diet used in the study, for example, set a “relatively achievable goal for most” featuring two 85g portions of red meat and five eggs per week, as well as a portion of poultry a day.
“This is not a radical vegetarian argument; it is an argument about eating meat in sensible amounts as part of healthy, balanced diets,” said Cambridge co-author Prof Keith Richards. “Managing the demand better, for example by focusing on health education, would bring double benefits, maintaining healthy populations, and greatly reducing critical pressures on the environment.”
University of Aberdeen co-author Prof Pete Smith, added: “Unless we make some serious changes in food consumption trends, we would have to completely de-carbonise the energy and industry sectors to stay within emissions budgets that avoid dangerous climate change. That is practically impossible, so, as well as encouraging sustainable agriculture, we need to re-think what we eat.”