Archer’s dodgy claims II … land use

Mike Archer of the University of NSW took a huge swing at vegetarians in a pre-christmas article on “The Conversation”.   It’s a bit difficult to deal with the central theme of the piece without first dealing with the factual errors that form the background. The mythology with which he frames his main point is far more important than the purported central claim.

This post concerns Archer’s mistakes about land requirements to feed a veg*n population.

Recall please any African wildlife documentary with savanna and antelope and zebra and lions. You soon notice that there is more grass than herbivores and more herbivores than carnivores. It just doesn’t work the other way round. This is a basic principle of ecology. Archer seems to understand this at the beginning of his article when he remarks that:

“It takes somewhere between two to ten kilos of plants, depending on the type of plants involved, to produce one kilo of animal. “

but then he effectively asserts the opposite without a shred of evidence.

The hazards of mythbusting …

The fundamental problem with an article like the one I’m writing … a myth buster … is that it can actually reinforce the myth by restatement. Myths are usually short and pithy, but busting them is usually complex and the short pithy myth can get remembered long after the complex refutation has faded. Hence my opening with the African savanna. Keep that in mind and you can’t go wrong.

Keep the savanna in mind

So here’s Archer’s claim:

“If more Australians want their nutritional needs to be met by plants, our arable land will need to be even more intensely farmed. This will require a net increase in the use of fertilisers, herbicides, pesticides and other threats to biodiversity and environmental health. Or, if existing laws are changed, more native vegetation could be cleared for agriculture (an area the size of Victoria plus Tasmania would be needed to produce the additional amount of plant-based food required).”

Notice the link, which should be to supporting evidence of some kind. In this case it goes to a Meat and Livestock Australia website which asserts something subtly different from Archer’s claim.

The claim on the MLA page isn’t about food, but about protein. It asserts a need for extra cropland if we want to produce the same amount of protein with plants as is currently produced by red meat.

How is that? MLA doesn’t say. So Archer supports an unproven assertion with a different but also unproven assertion and no hint of method or evidence anywhere.  

Let’s be clear here. Red meat production totals about 2.9 million tonnes of carcase annually. Can MLA really expect anybody to believe there is a less efficient way of producing this protein than using 27 million cattle and 70 million sheep grazing 420 million hectares of “natural” land together with a substantial fraction of Australia’s 22 million hectares of modified pasture and also consuming over 4 million tonnes of grain in feedlots.

Perhaps too much meat makes people gullible as well as red faced, fat and sick.

Here’s the numbers … MLA isn’t even close

A cattle carcase is about 13.9 percent edible protein and a tonne of wheat is 10.3 percent edible protein. So you can replace Australia’s entire red meat protein production (13.9/10.3=1.34) x 2.9 = 3.9 million tonnes of wheat grown on the land you save from not feeding 4 million tonnes of grain to cattle in feedlots. Notice we don’t need a shred of extra land, instead we can remove sheep and cattle from 420 million hectares,  many of which they are steadily degrading.

Hell, as well as the 4 million tonnes of grain eaten in feedlots annually, the beef industry during the 1990s deforested far more than 2-3 million hectares in Queenland alone. We can undo all that cattle driven deforestation.

So much for MLA, now back to Archer

Now that we know producing protein isn’t a problem, lets look at specifically how much crop land we could save by going vegetarian. I’ll do the numbers for vegetarians, but its easy to extend it for vegans.

FAOstat is the UN Food and Agriculture database, which contains food balance sheets for almost everybody on the planet. A food balance sheet tells you how much of each kind of food is eaten in a country. The latest data for Australia is 2007 and it shows that we eat about 1.8 million tonnes of cereals each year which provide 718 Calories per person per day. The 2.5 million tonnes of meat in our food supply (production-exports) provides just 508 Calories per person per day. Food supply figures like these are always a bit high because they include waste. They tell you how much is produced, but quite a bit ends up in the bin.

The Australian Bureau of Resource Economics (ABARE) keeps track of all kinds of interesting statistics. In 2008 it produced a feedgrain report which listed the quantity of grains used by various livestock industries. The meat industries consumed about 8.6 million tonnes of various grains … with another 2.6 million for dairy cattle. Given that 1.8 million tonnes provided 718 Calories and meat only provides 508 Calories, can we replace that 508 Calories using the 8.6 million tonnes of grain we save by not feeding livestock?

The answer is obvious. We could replace the 508 Calories with some of the grain and have about 6 million tonnes left over. At 1.5-2 million tonnes per hectare we could retire upto 3 million hectares of crop land.

Archer is wrong and the planet’s ecologists got it right, the lower down the food chain you eat, the less land you need. A vegetarian Australia wouldn’t grow quite the same mix of foods, but its easy to see that we would require far less cropland. So either we could return it to wildlife or increase our food exports.

Is 1200 Calories from cereals excessive? Again the FAO database tells us that Italy consumed levels even higher than this right through the 1960s and 70s. This was before their cereal intake fell and their meat intakes and obesity rates rose.  The level of overweight and obese males and females in Italy has now hit 44 and 29 percent.

And the fertiliser, herbicides and pesticides?

Because we need less cropping to feed a vegetarian population, we can either return the land to wildlife with a subsequent decline in pesticide, herbicide and fertiliser use, or increase our food exports. Whatever happens we will save on the fertiliser used for pastures. The 2008 National Inventory Report  lists the ratio of fertilisers used by different industries. An earlier 2004 report listed pastures as using the lion’s share of fertilisers, but this has been revised in the 2008 report. Pasture use is still substantial. 29% of fertiliser used in NSW is on pasture, 29% in NT, 28% in QLD, 33% in SA, 70%! in TAS, 49% in VIC and 39% in WA. A move to plant based diets will eliminate all that.

Similarly, herbicide and pesticide use isn’t confined to the plant industries. There are estimated to be upto 40,000 contaminated sheep dip sites in NSW alone.

Appendix on the protein myth

What about protein?

What about it?

This is the myth/reality problem again. MLA keep talking about protein as if it matters and so does Archer. Archer grew up during a period when it was mistakenly believed that the world’s hunger problems were driven by protein shortages. But his nutritional knowledge is stuck in a time warp.

By talking about protein, I may be keeping the myth alive.  But its better to understand why it isn’t a problem.

Fruit doesn’t have much protein does it? No. Of all the food groups, it’s the lowest. So what if you eat 30 bananas in a day? That will give you 3000 Calories … and about 60 grams of protein. Our NHMRC reckons a 70 kg guy needs about 47 grams (more on this below). So even on bananas you will get enough protein if you eat enough of them.  Replace some of those banana calories with vegetables or grains and your protein intake will actually increase! It’s really hard to avoid protein. Dietitians in hospitals formulating LOW protein diets for people with special problems have to use lemonade or deep fried foods to deliver calories without protein.

Here’s a link to a 124 page paper called “Explaining child malnutrition in developing countries” by experts from the International Food Policy Research Institute. You won’t find a single occurence of the word “protein”. The big factors in childhood malnutrition are Calories in the food supply, access to clean water, and levels of female education. It’s really hard to be protein deficient without also being starving or having your body too busy fighting water born disease to be functioning properly. Now imagine you are in a developing country with limited fencing. How will the cattle population affect the fecal contamination of your lakes and rivers and thereby the health and nutritional status of your children?

Ok, back to protein.

Our National Health and Medical Research Council estimates that a 70 kg male will need about 47 grams of protein per day … 42 grams for a woman of that weight … regardless of whether it is plant or animal protein. The recommended intake is quite a bit higher at 59 grams (52 for women) to allow a safety buffer that deals with individual differences. The current Australian food supply provides 109 grams per day with many people eating twice as much as recommended. People on high protein diets can easily be exceeding the NHMRC’s recommended upper limit which was set because of safety concerns.

So, what about protein? Whatever … irrelevant.