The Carnivore's (Ongoing) Dilemma
By Asa WahlquistAugust 30, 2012
Saving the planet is not as simple as 'less meat = less heat'. Indeed, the conscientious eater — particularly in Australia — might be better off with a steak than a slab of tofu.
When News Limited began its 1 Degree program, which aimed to make the company carbon neutral, it invited employees to submit the steps they would take to reduce their own personal greenhouse-gas emissions. In response a number of News employees offered to reduce the amount of red meat in their diets, or even cut out eating meat altogether.
In that choice, they joined such eminences as Britain's Lord Stern, the Nobel-winning Rajendra Pachauri of the Intergovernmental Panel on Climate Change, and the vegetarian Sir Paul McCartney who popularised the phrase: less meat = less heat.
Popular wisdom has it that industrial livestock production is killing the environment. But while there are some sound reasons to eat less meat or even become a vegetarian, doing it to save the planet is not necessarily one of them.
We can look at it this way: red meat comes from cattle and sheep, which play a vital role in utilising grasslands, the 60 per cent of the world's farmland unfit for any other agriculture. When the world's population of hungry people is rapidly growing, you have to ask whether we can ethically refuse to produce food from so much land.
We could also consider the fact that, on mixed farms — those that run livestock and grow crops — the animals play a critical role in eating farm waste and providing natural fertiliser. If human diets shift towards more legumes such as soybeans, that will mean more cropping and the accompanying need for more irrigation and higher inputs of nitrogenous fertilisers, which pose their own serious greenhouse-gas emission problem (more on this later).
As the implications of people swapping meat for vegetables are totted up, there are signs that the greenhouse-gas debate is changing.
In his book, Meat: A Benign Extravagance, Simon Fairlie, a British journalist and farmer, makes a strong case for sustainable, small-scale farming that incorporates livestock. So persuasive is his argument that Fairlie's book famously convinced well-known environment writer George Monbiot that his pro-vegan stance was wrong.
The case for meat is not helped by the fact that two of the earliest, most influential and most frequently quoted contributions to the debate are wrong. First was the Food and Agriculture Organisation's report Livestock's Long Shadow, which claimed 18 per cent of global greenhouse-gas emissions come from livestock. More recently, the International Panel for Climate Change put livestock greenhouse-gas emissions at 5.4 per cent of global emissions.
The other highly quotable early entrant was US researcher David Pimentel's claim that it takes 100,000 litres of water to produce one kilogram of beef.
However the Water Footprint Network estimates a global average water footprint of 15,400 litres of water per kg of beef. Beef grown on Australian farms seems to require less again, with research by a team including Brad Ridoutt from the CSIRO estimating water use at 6.6 to 440 litres per kg.
Ridoutt explains: "When people use these figures of 100,000 or even 15,000 [litres of water] these numbers go out into the public domain. The information is not given about what these numbers mean. It just becomes a source of misinformation that can be used in quite a scandalous way."
Ridoutt is working with the International Organisation for Standardisation to set up a rigorous system, similar to carbon footprinting, that would give comparable figures for water usage by all kinds of agriculture and other human pursuits. "The underlying question is to what extent is producing this product contributing to a reduction in fresh water that is available for the environment or for others to use."
Fairlie ridiculed Pimentel's figure, citing the case of Bramley, an Angus/Jersey cross steer he raised. He estimated that if the 100,000 litres per kg was correct, young Bramley would have had to consume about 25,000 litres of water a day.
What makes all this so difficult to precisely calculate is that we're talking about animals, not machines. Farmed animals are biological individuals with different constitutions and diets, living in different geographies, bred and used for different purposes, playing different roles in different farm systems. The result is huge variability in the productivity and resource consumption of livestock around the world: for example, beef produced in Africa in a Sahelian pastoral system — where cattle are used for transport, and ownership is an indicator of wealth — has the lowest carbon footprint at 8.4 kg of greenhouse gases per kilogram of meat; whereas beef produced in Japan, from the world's most pampered cattle, has the highest value at 26 kg of greenhouse gases per kilogram of meat.
Livestock's Long Shadow has cast its own long shadow over the livestock CO2 emissions debate. Richard Eckard, associate professor with the Melbourne School of Land and Environment, along with many other scientists, disputes their cliam that livestock contribute 18 per cent of the world's emissions, as it counts both cattle not raised for consumption and land not in fact used for livestock.
They say Long Shadow overestimated how much of the land clearing in the Amazon was for livestock — when up to 40 per cent is cropped with soybeans. Eckard adds: "You have all the cattle in India for religious reasons, the cattle in Africa used for transport and wealth generation — a lot do not get consumed."
Deforestation figures highly in Long Shadow 's sums, but Eckard points out much of Australia's rangelands were never cleared. "All the northern rangelands, they weren't cleared, they were just stocked with cattle," he says. In fact, most clearing, in Australia, has been for cropping.
Ross Garnaut's Climate Change Review, updated last year, reported that although greenhouse-gas emissions from livestock accounted for about 10 per cent of Australia's total, those emissions have declined by 13 per cent since 1990, largely because of a fall in sheep numbers — which dropped from 174 to 74 million. He pointed out that commercially motivated improvements in animal husbandry have "incidentally reduced emissions per unit of output. These developments could go further," Garnaut says.
The former chief of CSIRO Livestock Industries, Alan Bell, estimates beef cattle account for up to seven per cent of Australia's greenhouse-gas emissions. And that figure is set to fall. Townsville-based CSIRO scientist Ed Charmley says recent work shows cattle in the northern rangelands are producing 20 to 30 per cent less methane than previous estimates. With about half the nation's cattle in the north, this means a significant downward revision.
Most of the world's livestock consumes grass. Ruminant animals, such as cows and sheep, possess a special stomach or rumen which contains microbes that can digest grass — and a byproduct of that digestion is the greenhouse gas, methane. This means ruminants produce protein from plants in areas that are unsuitable for any other agricultural activity.
Grasslands occur on land where the soil is too poor, the rainfall too low or the topography too rough for the land to be ploughed and planted with crops.
And before there were modern cattle there were wild ruminants, including the great bison herds of the US prairies and the wildebeest of the African savanna, which had adapted to these grassy regions.
George Seddon has argued the main herbivores in Australia were termites, which, interestingly, also produce methane. Eckard says that in the Northern Territory "it is quite feasible that termites are producing more methane on an area basis than livestock".
Australia also has kangaroos, which, unusually among the large herbivorous animals, are not ruminants, and produce significantly less methane than cows, for example.
Methane, or CH4, is a potent, if short-lived greenhouse gas. It is given a global warming potential rating of 25 times that of carbon dioxide. Methane is the main component of natural gas and coal seam gas. It is also produced from landfill, but the largest source of methane is wetlands.
Eckard explains the quantity of methane a ruminant produces is affected by its diet — a poor diet results in higher methane production — and by genetics. He says there can be a 15 per cent difference in methane emissions within one herd, determined by these two factors.
The steak-versus-lentils argument is further complicated by the fact that grasslands have been found to play another important role in keeping our atmosphere in balance: that is, they sequester, or fix, carbon that would otherwise be released into the atmosphere.
Helen King, former deputy director of the Co-operative Research Centre for Greenhouse Gas Accounting, says, "There is a lot of research that [indicates] if areas [of grassland] are not grazed, or are not managed, they actually take up less carbon, so grazing animals play a very active role in the carbon cycle. Well-managed grass-fed beef is a totally different proposition to growing grains to feed animals or growing grains for consumption."
If people were to abandon eating red meat, some grasslands, like the Serengeti, might be repopulated by wild ruminants. But the more likely fate of Australia's grasslands would be consumption by fire. Bushfires, on average, burn over 500,000 square km of Australia annually, mainly the grasslands in the northern half of the country. Bushfire accounts for about three per cent of the nation's net greenhouse-gas emissions.
One of the charges made against livestock in general is that it consumes grains that would otherwise be used to feed people. But in Australia, livestock is largely fed grain and oilseed products that would not be used for human consumption.
Feeding grain to cattle doesn't bring great returns in the desired generation of protein: cattle require eight to 10 kilograms of grain to produce one kilogram of meat. Pigs, on the other hand, require three kilograms of feed and chicken requires just 1.7 kg of grain to produce one kilogram of meat.
Australians are eating less red meat, anyway. Beef consumption has more than halved since 1977, to 31.7 kg per person. Over the same period, consumption of chicken meat has rocketed from 15 to 45.2 kg per person. The great Aussie barbecue has paled significantly, which is, on one level, in step with our aims of greenhouse-gas reduction.
Every kilogram of beef produces 24 kg of greenhouse gases. Pork and chicken (both products of non-ruminants) generate much less, at 4.1 and 0.8 kg respectively.
And yet, "People say ruminants produce methane and are less efficient than pigs and poultry, but think about all that grain that we need to produce protein from pigs and poultry," Bell says. The argument has moved from red meat to meat and poultry generally.
Even Australian cattle don't spend their whole lives on grass; at any time, only about two per cent of the herd is in feedlots, being fed grain. Bell says feedlots are "a tough one for the environmentalists, particularly around methane". Many environmentalists oppose feedlotting due to its intensive nature and the high-grain diet. But feedlot cattle grow more quickly than grass-fed cattle, and that means they emit less greenhouse gas before they're slaughtered for their meat. As a result, Australian grain-fed cattle are estimated to produce 38 per cent fewer greenhouse-gas emissions than those raised on grass. They emit less again if they are administered Hormone Growth Promotants. In another context this would sound unpalatable, but here it makes sense.
Tara Garnett, from the Food Climate Research Network, at the University of Surrey in the UK, argues that if people didn't eat livestock, fewer cereal crops would be needed for livestock, but more would be required for humans.
Garnett also estimates that Britons throw out between 18 and 20 million tonnes of food a year. Australians are estimated to waste four million tonnes a year. Once, that food waste went to the pigs and poultry that were an integral part of farms and households — now it is simply wasted.
Animal products supply a third of all the world's protein. If we eliminated livestock we would have to produce half as much again vegetable protein crops to replace meat.
But in Australia the shift from pasture to crop land results in a reduction in soil carbon. Increasing soil carbon will be critical to Australia's future carbon balance. And the most effective way to increase carbon levels in soil used for agriculture is to return crop land to well-managed pasture, preferably native pasture.
And there's another problem. Crops need nitrogen, most of which comes from synthetic nitrogen fertiliser. Making nitrogen fertiliser is a very energy-intensive process, using at least one to two per cent of the world's energy supply. Then the fertiliser, once applied to crops, breaks down to become the potent greenhouse gas nitrous oxide, which has a global warming potential (GWP) of 298. The base unit for GWP is carbon dioxide, which is given a value of one at 20, 100 and 500 years. Methane has a GWP at 100 years of 25. There are other minor contributors, but carbon dioxide, methane and nitrous oxide are the three main greenhouse gases.
Organic farms fix nitrogen in the soil, naturally increasing its fertility through growing legume crops. And this lowers their productivity, because on a stockless farm, around one-third of fields are taken out of grain production for natural nitrogen fixing at any given time.
And here is the next conundrum for the environmentalist.
Garnett says that research into organic farms finds that, on the one hand, they are less energy intensive than conventional farming, but they are also less productive, so organic livestock is more greenhouse-gas intensive.
Bell hesitates to put a figure on the productivity of Australian organic farming, but says, "All the data I have seen, more from North America than here, says that organic is always going to be less efficient."
Can you absorb another complication? Because… there's the issue of what it takes to produce meat substitutes.
A study by Cranfield University, commissioned by the environmental group World Wildlife Fund, reported that many meat substitutes consumed in Britain are produced from soy, chickpeas and lentils that are grown overseas and imported. A switch to these substitutes would result in more foreign land being cultivated, and raise the risk of forests being destroyed to create farmland. It also found meat substitutes tended to be highly processed and involved energy-intensive production methods.
One of the study's authors, Donal Murphy-Bokern, said: "For some people, tofu and other meat substitutes symbolise environmental friendliness, but they are not necessarily the badge of merit people claim."
While the UK imports all its soybeans from cleared Amazon forest, last year at least, Australia grew about 14 per cent of its own soybeans, under fairly inefficient, water-sucking conditions. Ridoutt says consumers are demanding more transparent information about the water footprint and carbon footprints of their food. "In the States people are using their iPhones to download this kind of information, or reading it off bar codes."
But he warns that everyone needs to understand they are dealing with systems that are more complicated than current apps or bar codes can contend with.
"The first point is there is no simple quick-fix solution, such as 'Stop eating meat', because it is a complex system —there are consequences and knock-on effects." He cites the example of the push to "a more industrial meat-production system, based on chickens and pigs. Traditionally, a lot of these animals were raised on waste. Now, to make the productivity very high, very nutritious diets are being fed to them, so the land base that is supporting those forms of meat production is very much in conflict with the land base we might be using to produce cereals we might directly consume. You push in one direction, often it pushes out somewhere else."
In the meantime, something unexplained is happening to methane levels. Until 1999, as ruminant numbers rose, so did methane concentrations in the atmosphere. Then methane concentrations plateaued. No one is quite sure why. Bell suggests it could be due to drought and human activities, such as drainage, shrinking natural wetlands. Or perhaps the number of ruminants hasn't risen so much.
It certainly raised questions in some quarters about the importance of ruminant livestock in global methane accounting, and in the value of attempting to reduce it. Bell says that in the past two or three years the atmospheric methane level has begun to rise again, but it will be a couple of years before climate scientists can call this a real trend.
So what is the environmentally conscious consumer to do? Australians have a unique alternative to farmed meats: kangaroo. Eckard says kangaroos and wallabies have a microbial digestive system, similar to ruminants, except the main byproduct is succinate. While they do produce some methane, it is significantly less per kilogram than the volumes produced by ruminants.
There are only a few studies on macropod emissions. The most recent, on red-necked wallabies in the Copenhagen Zoo, found they produced between 25 and 33 per cent of the methane of a ruminant, per unit of food ingested.
That's just one hop in the bucket, so to speak, but overall, Eckard questions whether the emphasis on reducing greenhouse gases should be placed on agriculture. "If we are going to have greenhouse-gas emissions from something, is food production more legitimate than your transport preference?" This is the real nub of the question.
Fossil fuels consist of carbon, sequestered using the energy of the sun hundreds of millions of years ago. The scale of our consumption of this ancient carbon and sunlight is mind-boggling. Just four litres of petrol uses what was 90 tonnes of ancient life. In the space of one year, the world uses over 400 years of stored ancient energy and carbon.
As Helen King says, industrial use of fossil fuel is a one-way street. "Only the natural environment can take up carbon. Industrial emissions put carbon into the atmosphere, but can't take it out again."
There are so many conundrums for the consumer who wants to be environmentally conscious. If you walk or cycle to the butcher shop, take home some locally grown steak and cook it, to rare, over natural gas, is your carbon footprint smaller than if you'd driven to the supermarket, bought a soy-based product that was grown and processed overseas, then had to throw out leftovers because the kids wouldn't eat it?
One thing is clear: saving the planet is not as simple as giving up red meat.