"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," said Bajzelj.
"It is imperative to find ways to achieve global food security without expanding crop or pastureland. Food production is a main driver of biodiversity loss and a large contributor to climate change and pollution, so our food choices matter."
The team analysed evidence such as land use, land suitability and agricultural biomass data to create a robust model that compares different scenarios for 2050, including scenarios based on maintaining current trends.
One scenario investigated by the team is on the supply side: the closing of 'yield gaps'. Gaps between crop yields achieved in 'best practice' farming and the actual average yields exist all over the world, but are widest in developing countries particularly in Sub-Saharan Africa. The researchers say that closing these gaps through sustainable intensification of farming should be actively pursued.
But even with the yield gaps closed, projected food demand will still require additional land so the impact on GHG emissions and biodiversity remains. Bajzelj points out that higher yields will also require mo
|Contact: Fred Lewsey|
University of Cambridge