Eating less meat and reducing food waste is essential to ensure food security and avoid climate change, according to a new study published in the journal Nature Climate Change. Researchers from Cambridge and Aberdeen universities found that food production alone could exceed targets for greenhouse gas (GHG) emissions in 2050 if current trends continue. The authors warn that a growing population and a global shift towards meat-heavy diets will make it necessary to bring more land into cultivation. Increased deforestation, fertiliser use and livestock methane emissions could cause GHG from food production to increase by almost 80%. If we maintain ‘business as usual’, by 2050 cropland will have expanded by 42% and fertiliser use will have increased by 45% as compared to 2009 levels. The report says the situation can be improved if farmers in developing countries are helped to achieve the best possible yields from their land and if food waste at all stages in the food chain is reduced. But even with these measures, greenhouse gas emissions would still increase. The authors argue that a shift towards more balanced diets with less meat is needed. “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”, said lead author Bojana Bajzelj from the University of Cambridge. The researchers tested a scenario assuming an “average balanced diet” without excessive consumption of sugars, fats, and meat products, which included two 85g portions of red meat, seven portions of poultry and five eggs per week. “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. These three measures combined - closing yield gaps, halving food waste and switching to healthier diets - could result in agricultural greenhouse gas emissions almost halving from their 2009 level.