Probably fewer than half the contributors and readers of this blog are vegetarian, with a tiny percentage perhaps being vegan. A new study from Oxford University published in the Proceedings of the National Academy of Sciences of the United States might set some of us thinking about changing that, however.
With food in general creating over 25% of all global greenhouse gas emissions (including the need for transportation and all the rest), to think that about 80% of those emissions are linked to livestock makes one realize (once again, if we didn’t already know) the massive impact of eating red meat. Sarah DeWeerdt reports for Conservation magazine’s online section:
If every person on Earth adopted a vegan diet – without milk, meat, honey, or any other animal-sourced foods – the greenhouse gas emissions associated with the food system in 2050 would fall by more than half compared to 2005/2007 levels. That’s one of several striking findings from an analysis of food and climate published yesterday in the Proceedings of the National Academy of Sciences.
The food we eat is responsible for over one-quarter of global greenhouse gas emissions. Of those, 80 percent are linked to livestock production. Eating too much red meat and not enough fruits and vegetables are also linked to health problems such as cardiovascular disease and cancer.
Previous research has suggested that healthy diets could have environmental benefits and has explored ways to encourage such dietary shifts. But the new study is the first to quantify the health, environmental, and economic benefits of dietary changes all at the same time.
To do this, researchers from the University of Oxford in the UK combed through reams of data from the UN Food and Agriculture Association, the World Health Organization, and previous epidemiological and life-cycle analysis studies to compare the effects of various approaches to eating.
If current dietary habits and trends continue, the greenhouse gas emissions associated with the food system in 2050 will be 51 percent higher than current levels. This is due to factors including global population growth and the fact that as populations get wealthier they tend to start eating more meat.
But if everyone in the world followed international dietary guidelines for healthy eating, 2050 emissions from the food system would be held to just 7 percent over current levels, the researchers calculated. This is because, as a species, we would consume less greenhouse-gas-intensive red meat and more low-greenhouse-gas fruits and vegetables, as well as fewer calories overall.
Similarly, the researchers calculated that if everyone ate a vegetarian diet, consuming eggs and dairy but no meat, emissions would fall by 44 percent; emissions would decrease by 55 percent if everyone became vegan.
Read the rest of DeWeerdt’s synopsis of the journal article here.