At the United Nations climate change meet in Copenhagen last December, some of the most visible NGO campaigners milling around outside the conference venue were dressed as large, furry animals. As they distributed vegan sandwiches to all who would accept them, their message was simple: “Less meat means less heat.”
The policy debates surrounding global warming tend to focus on fossil fuels and carbon emissions. Solutions to climate change, correspondingly, centre on developing renewable energies and increasing efficiency in the transport and building sectors. Far less attention is garnered by the warming consequences of rearing and consuming livestock. In fact, the methane released when ruminants like cows and sheep belch or pass gas, which they do copiously, combined with the indirect emissions associated with their life cycles, contributes 18 percent of greenhouse gas emissions worldwide, even more than the transport sector.
This figure was arrived at by a United Nation’s Food and Agriculture Organization study, conducted in 2006. Yet, meat and dairy consumption continue to suffer from scant mention in most popular expositions of climate change science. Al Gore’s movie, An inconvenient truth, for example, avoids what may be the most inconvenient truth of all, that what’s on the dinner plate can link to climate change as much as driving an SUV.
The FAO study took into account both the direct and indirect emissions related to livestock. Thus, emissions arising from feed production, including chemical fertiliser production, deforestation for pasture and feed crops, cultivation of feed crops and feed transport were added to the direct emissions of the animals in question, in particular their enteric fermentation (which results in their passing gas) and the nitrous oxide emissions released from animal urine and manure. Animal waste management and livestock transportation were other aspects accounted for.
According to the FAO, livestock contributes only about nine percent of total anthropogenic carbon dioxide emissions, but 37 percent of methane and 65 percent of nitrous oxide emissions. This is significant because methane and nitrous oxide cause far greater warming than equivalent amounts of carbon. Methane has a global warming potential (GWP) of 21, meaning a tonne of methane in the atmosphere produces as much warming as 21 tonnes of carbon dioxide over a 100-year period. Nitrous oxide has a GWP of 310.
The FAO study has met with considerable criticism. Mick Keogh, Executive Director of the Australian Farm Institute, lists some of these in a recent article, in which he claims the FAO methodology was faulty, leading to substantial double-counting of emissions. He also objected to the fact that the FAO included emissions from deforestation and desertification as part of the impact of livestock, when much of this activity occurs for non-livestock related reasons. And, while admitting that methane has a far greater warming potential than carbon, he noted that carbon stays in the atmosphere for up to 100 years, whereas methane only lingers for eight to 12 years.
Data from the IPCC (Intergovernmental Panel on Climate Change) has a much lower figure for livestock-related greenhouse gas emissions. It estimates direct livestock emissions to make up approximately half of total agricultural emissions or some seven percent of global emissions.
“The way in which you attribute emissions depends on what your aim is,” says Pierre Gerber an FAO Livestock Policy Officer, explaining the difference in numbers. “Our aim was to find out how much animal production was sufficient to maintain food security while doing the least amount of harm to the environment. In the context of the food security-environment nexus, our methodology was the best.”
An even more damning study in the November-December issue of World Watch magazine added fresh fuel to the meat and global warming debate. The report claimed more than half of human-produced greenhouses gases were caused by meat industries.
These latest findings are fiercely contested, particularly the fact that they include all carbon dioxide released by livestock during respiration. Nonetheless, advocacy of vegetarianism as the solution to climate change is on the up. Speaking at the European Parliament last December, singer Paul McCartney urged legislators to support citizens in refraining from eating meat one day in the week. He was joined by the IPCC chairman, Rajendra Pachauri, who is a vegetarian and recommended the levying of a surcharge on beef as a way of reducing consumption.
The Australian Farm Institute’s Keogh, lashed at Pachauri, saying that the emphasis on meat rather than dairy betrayed the bias of his home country, India. India is home to the world’s largest national cattle herd, and rapidly increasing levels of per capita dairy consumption, although many Indians are vegetarian. “Perhaps the dairy industry has been ignored because ‘less ice-cream means less heat’ might be harder to sell to consumers,” said Keogh.
But, the FAO says its policy recommendations apply equally to dairy and meat. “There is a substantial impact by livestock on the environment,” says Gerber. “That is a fact. Governments need to find ways to minimise that impact by more efficient management of animal waste and feed production.”
Gerber also says it is possible to reduce the direct emissions of ruminants by making changes to their diet. “In India, on the whole, the yield of a cow is very low. If you can improve yields, then you can have fewer cows for the same amount of milk, which will reduce total emissions. Breed and feed are the two determinants that impact yield.”
The FAO will be publishing a new study at the end of the year, including the latest research that has been conducted over the past three years. It will stress that technologies are already out there that could help mitigate the impact of livestock on climate.
One such innovative project is currently being undertaken by Australia’s Cooperative Research Centre for Sheep Industry Innovation, where scientists are attempting to identify sheep that are genetically predisposed to less flatulence.