Climate change

October 14, 2008

The global food system and climate change – Part I

Filed under: Livestock's long shadow — Barry Brook @ 10:53 am

Guest Post by Geoff Russell.

Geoff is a mathematician and computer programmer and is a member of Animal Liberation SA.


Late in 2006 the United Nations Food and Agriculture organisation published one of those huge thick reports that gets a one column story in quite a few newspapers and then vanishes from sight. It is Livestock’s Long Shadow (LLS).

The report is a compendium of data and analysis on the impacts of the livestock industry on the earth’s eco-systems. There are major chapters on land degradation, air pollution, water pollution, biodiversity, with concluding chapters on policy options for reform and expansion.

This is the first of a few posts which will review major parts of the report. I’m not aiming at an comprehensive review, but rather at presenting key pieces with other relevant information which should allow people to appreciate the linkages between the global systems of food, feed, livestock and their impact on climate change. Remember always that food is what people eat, and feed is what livestock eats. We will begin by looking at the first two LLS chapters which provide structural background for the remainder of the report.

Keep in mind that LLS is written by people advocating an expansion of the livestock industry while I advocate a reduction. Hence my choice of the term factory farm instead of the more euphemistic intensive/landless used in LLS.

Let’s start with a couple of tables which serve to give an overview of the structure of the global livestock system. These tables will also show that the Australian livestock industry is somewhat unusual.

Global Livestock Output

The first table is a who’s who of agricultural commodities. Most of us live in a single dwelling and buy major items of metal, wood or plastic infrequently, but we all eat everyday and the global ebb and flow of food largely determines our appropriation of the planet’s resources. Forestry, for example, causes just 3% of Amazon deforestation. In Australia, we have cleared 100 million hectares since white arrival, but forestry operates in just 13.3 million hectares, most of which are not cleared. We crop just 24 million hectares and urban areas occupy just 1.6 million. Here as elsewhere livestock is the primary driver of land clearing and biodiversity loss.

Meat Production Millions of Tonnes

Production System




Factory Farm










































Food and Feed Production Millions of Tonnes









Fish, Seafood




Palm/Soybean Oil


The data I’ve assembled in this table is an amalgam of parts of LLS Table 2.9 with a little data from the FAO and the US Department of Agriculture on plant food and seafood. The palm oil/soy oil figure of 70 megatonnes comes from USDA. It is faily evenly split between the two oils. The fish-meal figure is from LLS but was checked against with the International Fishmeal and Fishoil association. They give a similar figure and the implication is that global fish-meal, created annually from 30-35 million tonnes of fish, is entirely consumed by livestock (including aquaculture). LLS explains that as aquaculture expands it requires fish-meal, because the fish of choice, like tuna and salmon are carnivorous and require fish in their diet. Despite what you may have heard, people don’t need to eat sea food of any kind. As aquaculture diverts fish-meal from livestock feed, this leaves a hole filled increasingly by soy.

The top section of the table is meat production, the bottom is the major components global plant production, which is a combination of food and feed. We will see later just how much of this production is appropriated for feed.

This is a complex and dense table and we will spend a little time highlighting things that an Australian might find surprising. It is customary to quote meat figures as carcase weights. But you only eat 60-75% of the carcase, so the edible meat will be somewhat lower than this table indicates.

There are 4 kinds of production systems. The two in the middle are mixed systems. These are farms which grow some or all livestock feed for the animals they produce. This implies that some or all of the farm is suitable for crops — arable. A factory farm gets all its feed from somewhere else. So a factory farm competes with humans for the plant food products at the bottom of the table. Absent from the bottom of the table are fodder crops. These are important in many livestock systems. Australia, for example, has an area of irrigated hay and silage production about 50% bigger than our entire irrigated fruit growing areas. In 2005/6 we applied 770 giga litres of irrigation water to this area, which is about 100 giga litres more than we applied to fruit trees. Global fodder figures are missing from LLS but we will revisit the issue when we deal with Chapter 4 of LLS and water issues.

In Australia about 2/3 of beef and half of our dairy products are exported. Ignoring that, beef and chicken consumption are similar with pork being about half the size. Globally on the other hand, pigs dominate the meat industry and chicken production is bigger than beef. In Australia, almost all pig and chicken meat is produced in factory farms.

So the Australian meat production profile, with its beef dominance, is rather different from the global average. But since chicken and pig meat outsells beef locally, over half the meat consumed in Australia is produced in factory farms. Globally, factory farmed meat is just under half of all meat.

The total global production of 241.5 million tonnes sounds like a lot of food. The UN Food and Agriculture Organisation also keeps accurate data on plant food production and contains what are called Food Balance Sheets on its statistical website. If you take the production figure, add the imports, subtract the exports and animal feed, you get the amount of each food left for people to eat. Divide this amount by the population and you get the calories per person per day.

All up, animal food, which also includes fish, milk and cheese, provides 17% of the daily average of 2808 calories. If you think that protein would be a more flattering measure of the value of animal production then you would be right. But until very recently in human history, a diet with adequate calories provided adequate protein. These days, a diet of coke and fries can simultaneously make you obese and protein deficient. For more background on protein see the section below.

Global Inputs

The LLS map on the left shows the distribution of livestock production systems which provide this 17% of global calories. Livestock graze 26% of the ice free surface of the planet, about 3.4 billion hectares (about 4.4 times the area of Australia). But we can see from the above table that this vast amount of grazing land produces a fairly small proportion of global meat. A grass fed cattle carcase in Australia or from the Brazilian Amazon comes in at 200-250~kg. But a grain fed feedlot animal produces a 350~kg carcase.

In addition to pasture, livestock consumes the output of 471 million hectares of the crop land. This is about one third of all current crop land shown on the left.

All up then, animal foods use 471 million hectares of crops + 3,400 million hectares of grazing + the entire and declining output of both fresh water and ocean fisheries but provide just 17% of global calories. Plant foods provide 83% of global calories from 940 million hectares of crops. Based on current cropping outputs, if people switched to totally plant based diets, we could return the full grazing area of 3,400 million hectares to other species, together with a significant proportion of the 471 million feed hectares. At the other extreme, if the entire 6.7 billion of the world’s population ate like the richest 1.4 billion, then massive increases in both grazing and cropping areas will be required.

Food becomes feed

Feed use in 2002 (million tonnes)

Developing Developed
Commodity countries countries Total





















Fish meal










Now we are ready to look in a little more detail at the global feed consumption of livestock. So here it is, together with an added row giving the total biofuel use of grains in 2007. As you can see, the biofuel contribution to the current global food crisis is pretty much a straw on the back of a camel laid low by the burden of global meat production.

The oilcakes row is interesting. Oilcakes are a byproduct of making oil from soybeans, peanuts or various other oil yielding plants. Oilcake is typically very high in protein and minerals. Overall, LLS estimates that 77 million tonnes of protein is fed to animals in food suitable for humans for an output of 58 million tonnes.

Australian Grain Feeding

2005/6 million tonnes

Feedlot Cattle










Grazing Sheep/Cattle




Source: ABARE Feedgrains report 2007

Of course, when the global food crisis hit in early 2008, even Oxfam jumped on the blame-biofuel bandwagon while ignoring the industry which supplies the beloved Aussie BBQ. How much food do we use as feed in Australia? Here are stats from 2005/6. In the following year, 2006/7, because of ongoing drought in Australia, we imported about 2 million tonnes of feed grains. So, in a very real sense we helped to exacerbate the global food crisis in two ways. First with the import of grains, and second by the normal use of about 11 million tonnes annually to feed cattle, pigs and chickens.

Deforestation and land degradation

This map shows the global area regarded as either vulnerable (yellow) or critically affected (red) by livestock.

Unsurprisingly, LLS cites land use change as the leading cause of global biodiversity loss. Clear a forest for soybeans or cattle and the plants and animals of that forest will die. But of course, we reasonably put out own own need to eat above that of wildlife, but we can choose to minimise the damage. Or not.

LLS describes the mechanisms whereby livestock damage land. On rangelands, we have the holy trinity of extensive livestock production with which any visitor to the Australian outback who knew what to look for would be familiar: desertification, increased woody plants, and deforestation. Queensland’s destruction of Brigalow forests during the 1990s was particularly savage. On a per-capita per-hectare basis, this deforestation surpasses anything in Brazil or Indonesia – the two acknowledged superpowers in the deforestation race.

Factory farms produce different environmental problems. Any damage done during cropping for feed production should be attributed to them and not to plant food production. Water pollution can cause eutrophication, ground water contamination, red tides, blue-green algae and dead zones. Such events can have non-livestock causes, but modern livestock numbers can easily impose intolerable loads on natural systems.

In the US, there is often better data available than elsewhere and LLS presents a figure of 55% as the amount of erosion on both crop land and pasture which is due to livestock either directly or via feed production. This erosion and loss of topsoil has the potential to cause a crisis in global food production that will make this year’s crisis seem insignificant.

Typically, the manner of deforestation is more complete for crops than than cattle. So the obvious question is whether it preferable to clear a small area completely or to clear a much larger area, but less intensively, for grazing?

Forest and Soil Carbon Distribution (tonnes/ha)
Above ground Below ground
Wet Tropical Forest






This table isn’t from LLS, but from a key study into grazing systems relied upon by LLS (Asner et al, “Grazing Systems, ecosystem responses and Global Change”). It shows figures for above and below ground carbon for a tropical forest and grassland. Clearly, a grassland is a poor substitute for a tropical forest as a carbon store. In between grasslands and wet tropical forests are all manner of woodlands with values anywhere between these extremes. When a tropical forest is cleared, it isn’t only the above ground carbon which is lost, much of that below ground may be lost over coming years. Cattle grazing tropical soils compress the ground as elsewhere, but the result can end up with decomposition becoming anaerobic and the soil can become a methane source. More on this later in this series.

The basic transformation of livestock production during the past 50 years has been driven by the simple fact that grasslands which are both available and suitable for grazing are already used. They are not only used, they are frequently degraded. In Australia, we don’t need global studies like LLS to tell us about either deforestation or degradation. We are world leaders in both.

This map shows areas which are both highly suitable and available for grazing. I’ve shrunk the map, but the green areas are forest areas, the yellow are crop areas and the red are urban areas which are currently on land suitable for grazing.

As a result, increases in meat production that have been achieved during the past half century have been due to intensification or deforestation.

Jared Diamond estimated back in the late 1990s in “Guns, Germs and Steel” that gatherer/hunters need 10 to 100 times more land than farmers. Similarly, extensive livestock need more land than intensive livestock, for similar reasons. Most native grasses are, or have been thought to be, less than optimal for maximising livestock growth, so if you want maximum growth, grow the feed elsewhere (or locally) using intensive methods with plenty of water if possible, and fertiliser. Alternatively sow your pasture with grasses selected for maximum productivity and add fertiliser. Australia spent 70 years introducing 5000 species of grasses and legumes in an attempt to improve on native grasses for livestock growth. Fertilisation of non-irrigated pasture is common. In 2005, for example, non-irrigated pasture uses 39% of total nitrogenous fertiliser in New South Wales, 35% in the Northern Territory, 60% in South Australia and 44% in Victoria.

Apart from intensification, the second key to the increase in meat production over the past 50 years has been increased is by shifting from biologically inefficient feed converters, large ruminants, to efficient feed converters, pigs and chickens. The third key to increased production has been a spatial shift. Cattle grazed on rangelands have to be moved to where the consumer lives, typically nowhere near the rangelands. Pigs and chickens are kept in huge sheds fairly close to cities. It is far more efficient to ship feed to factory farms than to ship live animals to abattoirs.

In the next post, I’ll get down to the detail of climate change impacts of the food system in general and livestock in particular.

Nutritional Appendix

We showed earlier that feeding the global population with plant food would release huge amounts of grazing land for other species and even some cropping land. This is an extreme in the spectrum of possible change and has a low social feasibility. But this post is only concerned with scientific feasibility. To show that this is scientifically feasible, we need to show that, contrary to popular belief, animal protein has no practical advantages over the plant proteins found in standard plant staples like, for example, wheat, beans or rice.

The Australian National Health and Medical Research Council’s 2006 Nutrient Reference Values of Australia and New Zealand lists protein requirements without distinguishing plant and animal protein requirements. This is because there are no relevant differences between plant and animal protein where food intake is adequate. And when food intake isn’t adequate? What then? The weapon of choice at present in saving malnourished children is a product called Plumpy’Nut. It is basically a fortified peanut butter. Compared with traditional fortified milk based products, the peanut based formula works better (restores growth and health faster), is less prone to infection with pathogenic bacteria, is cheaper and doesn’t look like milk. The latter is an advantage because health workers have a hard time persuading mothers to breast feed when the treatment for malnutrition looks like milk (Am J Clin Nutr 2003;78:302-7).

It is worth quoting one last statment on the adequacy of plant based diets from the Professor of Nutrition at New York University, Marion Nestle, who happens not to be a vegetarian, who states in her recent book What to Eat: “The meat industry’s big public relations problem is that vegetarians are demonstrably healthier than meat eaters.”

This of course is a statistical statement. Vegans and vegetarians consuming frequent meals of coke and fries will get sick just like anybody else eating too much of these foods.

So how much protein does animal food currently provide? All up, despite using 33% of arable land plus a massive grazing area, animal food production only supplies 38% of the daily average of 76 grams of protein for each person on the planet. This is likely to be an overestimate because of the use of carcase figures in the data. However animal food distribution is not uniform and makes up far more of the diet of the 1.4 billion people in the developed world with animal protein being about 50% of all protein. Animal protein is about 30% of protein in the other 5.3 billion people on the planet.


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