Becoming vegetarian will not help climate
change, and it would create many new problems, claims an American professor in
animal science.
Despite the widely held belief that animal
farming causes disproportionally high levels of global anthropogenic greenhouse
gas (GHG) emissions, the concept of vegetarianism as a solution to reduce emissions
was challenged by Dr Jude Capper in her address to the Climate Change Research Strategy for Primary Industries conference in Melbourne in November.
An Adjunct Professor of Animal Sciences in
the Department of Animal Sciences at Washington State University, Dr Capper
describes herself as a “livestock sustainability consultant” who is “passionate
about sustainability issues and the role of animal agriculture in helping to
feed a hungry world”, so it perhaps not surprising that she supports eating
meat.
“Whole-scale vegetarianism is not a
solution that will mitigate GHG emissions, but simply a panacea offered at the
expense of consumer choice and dietary diversity,” she said.
She paints a
picture of a world in which the only livestock would be found in zoos or conservations parks; points out that
other resources would be needed to make by products such as leather,
fertiliser, tallow and pharmaceuticals, and even asks how we would feed
Australia’s 5.75 million pet cats and dogs.
As an extreme side effect, Capper says that, by feeding on the “leftovers”
of plant farming, animals convert this to useful protein; without this, the
organic material would go to landfill and produce methane (although arguably
the biogas from anaerobic decomposition could be collected for use as biogas,
or it could be used to make aerobic compost).
The most common argument for reducing meat
production stems from calculations that attribute 18% of GHG emissions to
animal agriculture [Livestock’s Long Shadow, UN Food and Agriculture Organisation, 2006]. Capper points to
admissions by the report’s author that this figure needs recalculating, however
she agrees: “enteric methane emissions are an invariable consequence of
ruminant livestock systems, and manure from both ruminant and monogastric
animals is a significant contributor to atmospheric methane and nitrous oxide”.
In the USA and elsewhere, ‘Meatless
Mondays’ is being promoted as a way of reducing the impact of animal
agriculture, however Capper says the “claims for a significant improvement in
environmental impact appear to be over-exaggerated”. One claim is by researchers from Carnegie-Mellon University concluding that: “Switching less
than one day per week’s worth of calories from red meat and dairy products to
chicken, fish, eggs or a vegetable-based diet achieves more greenhouse gas
reductions than buying locally-sourced food”.
By Capper’s calculations, based on US EPA figures that red meat and
dairy production contributes 3% of annual GHG emissions, if all Americans
avoided meat and dairy once a week, this would cut America’s national GHG
emissions by just 0.42%, or less (0.29% if only meat was omitted).
The savings could be potentially much higher in Australia, where animal agriculture accounts for 11% of GHG, but 60% of this is exported.
Asked to respond,
Sydney PhD student Judith Friedlander, who is
researching food sustainability and the media, said that choosing to eat less
meat is something effective that consumers can do easily.
She said there was enough evidence to show
that meat and dairy production have a substantial impact on emissions and that,
while these industries are working to become more efficient, the potential for
reduced emissions through technical mitigation options is estimated to be
limited to 15-20% (Weidema et al 2008 and Wirsenius and Hedenus 2010): “So a
reduction in consumption of livestock and meat products is also vitally
important to cut emissions."
Capper disagrees. Despite Stockholm International Water Institute findings that there is not enough water to support the predicted increase in
population and that meat consumption will be need to be cut, she points out
that dairy production in the US has reduced GHG by 63% and water use by 65% per
kg of milk since 1944, while GHG emissions and water use per kg of US beef have
dropped by 16% and 12% respectively since 1977.
Environmentalists often claim that it takes 10, 20 or even 30kg of grain
to produce a kilo of beef, Capper resorts to a rather specious argument that
corn only accounts for 7% of the feed used to produce a kilo of beef in the USA
and, anyway, who wants to eat feed-quality corn? Unfortunately she does not
compare the equivalent land use of producing protein-rich chickpeas or soya,
although she does make the relevant point that only a small proportion of
grazing land is suitable for growing crops. And she highlights the point made
by Fairlie (2010) who compared resource use for various diets, that more land
would be needed to feed 7 billion people on a vegan diet, due to the lack of
animal fertilisers, and the need for more oil-producing plants to replace
animal fats.
“Both dairy and grass-fed beef cattle produce a greater amount of
human-edible food than they consume,” she argues.
Take the amino acid balance and protein quality of animal proteins
compared to plant-based foods, and Capper says: “this strengthens the rational
for maintaining omnivorous diets”.
