Meat lovers will have to rein in their love of steaks and burgers if they hope to keep the planet safe from the warming effects of greenhouse gases, according to a study published Tuesday by the Proceedings of the National Academy of Sciences.
A team of scientists from Canada's Dalhousie University said livestock production could be responsible for as much as 70 percent of the total greenhouse gas emissions considered a safe threshold by the middle of the 21st century.
Raising cows, goats and sheep contributes to global warming in several ways, they suggested. It destroys habitat as land is cleared to make way for pasture. Nitrates used to grow feed contribute to acid rain and smog. Furthermore, cows, goats and sheep all emit unusual amounts of methane and nitrous oxide due to the very indelicate ways they digest their food.
The study authors claim humans should cut their meat consumption by at least 19 percent, and possibly as much as 42 percent, by 2050 to keep greenhouse gases from livestock in check.
This is not the first time this argument has been made and has stirred up controversy. There is wide disagreement over just how big an impact a switch to vegetarianism would have on climate change.
The authors argue in this study that other research that promotes mitigation strategies such as using manure rather than nitrogen fertilizers will not achieve enough reduction in pollution to sustain meat consumption at current levels.
A study published in British medical journal, The Lancet, in 2007 advocated a reduction in meat consumption after concluding that technology could only reduce livestock emissions by less than 20 percent.
The authors noted that it is not likely the world will convert to vegetarianism. But they stressed the information should be taken into account when creating green policies and to help people make choices in their diets.