Ecologic
A bit of a beef
by Dave Hansford
We should be doing more with our land than simply grazing cattle.
A strident warning on food security came last month from the British Government’s chief scientist, Professor John Beddington. Climate change, he said, will put extra pressure on global food supplies as a result of lower rainfall and crop failures. “The agriculture industry needs to double its food production.”
Biotech companies were quick to pick up on his comment, claiming only genetic modification can save us. But we can do something much simpler. We can eat less meat.
More than a billion cattle are grazing on our planet. Their biomass is almost twice that of the human race. One cow needs a hectare of prime grazing, or 20ha of poor land, to support it; thus the global herd occupies a third of Earth’s available land mass.
We could be doing a lot with that land. For instance, we could let some of it return to rainforest to soak up carbon. Seventy-four million cattle are reared in the Amazon Basin, where they outnumber people by more than three to one. Nearly 18% of the Amazon rainforest has been cleared, much of it for beef production to feed American hamburger chains. Or we could plant vegetables. A hectare of beef production feeds one person; a hectare of potatoes feeds 22.
In the US, 22.6 million hectares are devoted to growing hay for livestock; only 1.6 million hectares are given over to growing produce. That livestock also consumes 70% of all grains and cereals produced in the US. According to the US Department of Agriculture, it takes more than 7.2kg of grain to produce 450g of feedlot beef.
New Zealand’s beef herd is more environmentally benign as it’s raised mostly on pasture grass, but the numbers are still interesting. Researchers say breeding cows consume 85% of all feed eaten by beef herds, so just 15% of all the pasture and supplementary feed the national beef herd chomps through is converted to edible beef. Of course, the replacement stock the breeding cows are producing does represent future beef production, but only half of their 85% goes towards this, as the other half goes solely on maintaining breeding cows’ body weight. By contrast with the breeding cows’ 85%, breeding pigs and poultry consume a mere 10% of total feed.
Our production might be less energy-intensive, but we add our weight to the ecological footprint of our overseas trading partners when we export.
Quite apart from its methane emissions, global livestock production accounts for some 9% of CO2 when deforestation and land-use practices are taken into account. The fertiliser used to drive this production generates 65% of human-induced nitrous-oxide emissions.
A Stockholm University study took four different meals with identical protein and energy content and compared their life-cycle greenhouse gas emissions. A vegetarian meal of local ingredients resulted in CO2 emissions of 190g; a meal of local animal and vegetable origin was twice that at 380g. But when non-local ingredients were used in the vegetarian meal, the CO2 emissions climbed to 860g. And for the meal containing imported pork, rice and tomatoes, the emissions hit 1800g.
The good news, however, is that you don’t have to give up meat altogether to be a more sustainable diner. A study at Cornell University last year found a vegetarian needs only 0.17ha to produce their food, whereas a meat eater needs 0.85ha. But, said lead author Chris Peters, “a vegetarian diet is not necessarily the most efficient in terms of land use … Diets including modest amounts of meat can feed more people than some higher fat vegetarian diets,” said Peters.
As Friends of the Earth director Tony Juniper says, “Cutting our meat consumption by half would align our diet with a more sustainable food economy.”
