‘Greenhouse Cost of Meat’ article by Geoff Russell June 2007

Introduction

Many people understand large motor vehicles produce more greenhouse emissions than a small motor vehicles, and many have heard that the Toyota Prius can save about 1.5 tonnes per annum in emissions, but few realise that the biggest driver of greenhouse emissions which people have direct personal control over is food production — particularly meat.

The eco-footprint calculator on the Australian Conservation Foundation web site uses a very sophisticated data base and model from Sydney University and CSIRO research, but has been simplified for easy public use. The ACF calculator gives you a breakdown of your impact as measured by water use, land use, and greenhouse gases production. It’s very illuminating (and perhaps surprising) to play with this calculator to compare the options of different lifestyle changes on greenhouse emissions. I tried slashing electricity use in half from a $340 quarterly usage to a $170 usage. That gave a savings of 1 tonne of emissions per annum. Next I looked at the difference between using going from $100 per month petrol use to $20 per month. This saved about 2 tonnes of emissions per annum. Lastly I compared a person on the CSIRO diet (14 red meat serves per week — a serve is 60-100gms) to a vegan diet. This saved a massive 5.7 tonnes per annum.

Why is it so?

To understand the above results we need to understand the meat production chain. This chainis long and energy rich. It starts not with cattle trucks or butcher’s freezers but further back, much further back. Australia has always been a large grain producer, but we now feed more grain to animals than our entire 1960’s production (REF). During the 2002-2003 drought, we imported hundreds of thousands of tonnes of grain to feed animals. While manyof Australia’s beef cattle are still raised on grass, they are increasingly finished infeedlots. Pigs and chickens are all fed on grain.

We also need to understand that ruminants produce a great deal of methane and that methane is 21 times more potent as a greenhouse gas than carbon dioxide.

So the meat production chain starts with driving grain to feedlots? No, it goes back even further. In their efforts to raise both productivity and grain protein levels, Australia’s farmers are using increasing amounts of nitrogen fertiliser. The tonnage used doubled to 1,560,000 tonnes between 1996 and 2002. One tonne of nitrogen fertiliser takes about 18,000 kilowatt hours of energy to produce (the usual energy source is natural gas) using a chemical process called the Haber-Bosch process.

What happens when you apply nitrogenous fertiliser? It is very concentrated, so much so that the plants can’t use it all and the excess becomes a potent pollutant of soil, water, and air. The soil gives off nitrous oxide. Nitrous oxide is 310 times more potent as a greenhouse gas than CO2.

Quantifying the meat production chain

The ACF eco-footprint calculator is only hosted by ACF. It comes from a Sydney University team and is based heavily on work done in the CSIRO/Sydney University Balancing Act report. This 2005 report looked at the flow of goods and services through the Australian economy in an exercise to allocate greenhouse gas emissions to the economic sector responsible for their production. Ideally in this sort of study, if aluminium is smelted to make a ladder used by an apple picker, then the emissions are allocated to “fruit and vegetables”, if the aluminium is used for a tuna fishing boat then the emissions are allocated to “fish products”. The way this analysis proceeds is using statistical data produced every few years by the Australian Bureau of Statitics called “input-output” tables. These tables, in effect, determine what proportion of aluminium goes to the ship building industry, so the emissions for that much aluminium flows to the ship building sector. For the ship building sector they determine what proportion of boats are for fishing and what are for pleasure and so on.

The end point of this analysis is that all of Australia’s 550 Mt of CO2 ends up in what is called “ final consumption”. All industries exist to supply consumers — eventually. A printing company prints brochures for a bolt company which supplies bolts to a workshop which makes machines for a fridge company which supplies friges for people — at which point the chain stops.

This type of analysis tells you why energy is used. This is in stark contrast to the Australian Greenhouse Office figures which lump greenhouse emissions into industry sectors without considering what final consumption purpose the industry serves. The AGO 2003 figures tell you, for example, than 266 Mt of our emissions were from stationary energy production. The implication that most people draw is that this is mainly electricity and that energy saving devices will help. What the CSIRO report tells us is that only about 34% of electricity emissions are from consumer use. Most electricity is used by industry, not for final consumption.

The following figure summarises some of the final consumption categories into which the CSIRO allocated emissions.

As you can see from the figure, electricity produced (48+90=138) mega tonnes of emissions. Most went to industry. The combined ruminant emissions were (123+31=154) mega tonnes. And this is before processing. Some meat goes to hotels and the leather industry, so not all the greenhouse emissions associated with animal production actually end up in the meat products category. Neverthess we know that the total will exceed 154.

We can also see that the meat emission figures dwarf the passenger vehicle emissions which come to 43.5 mega tonnes. The 24 hour per day emissions of methane from 28 million cattle and 100 million sheep dwarf the carbon dioxide of several million motor vehicles which are parked for most of most days.

I mentioned nitrous oxide emissions above — which don’t all end up in the meat category because not all fertiliser is used to grow feed grains. Also not all nitrous oxide is from nitrogen fertiliser, however nitrous oxide is a significant greenhouse factor. Australian Greenhouse Office (AGO) figures put nitrous oxide emissions at 24.8 Mega tonnes CO2eq (All greenhouse gas figures are expressed in CO2eq — the equivalent amount CO2). All of Australia’s passenger vehicles, by comparison, emit 43.5 Mega tonnes.

Lasse Halstrom’s 1985 film, My life as a dog has for its central character’s main line one should always compare. Nothing could be truer when it comes to greenhouse emissions!

What if the Chinese switch to beef?

Many people seem to consider the ultimate environmental catastrophe will be if a billion Chinese start driving motor cars with the same intensity as Australians. Many frightening figures can be produced using this hypothesis.

But here’s an even scarier thought — what if the Chinese start to eat beef like Australians?

UN Food and Agriculture figures show that currently the world produces 568 calories of rice per person per day and 40 calories of beef per person per day. Nevertheless the methane produced by livestock is 90 megatonnes/yr compared with just 60 megatonnes/yr for rice[1]. Clearly any major dietary shift from rice to beef would lead to a large methane increase — which would be disastrous. It also follows that shifting from beef to grains would decrease methane. Methane has a fairly short lifespan in the atmosphere, hence a dietary shift to grains will have a much quicker effect than any reduction in CO2 emissions. Senior NASA Climate Change modellers now think that controlling methane could be a critical first step in attacking climate change[2]. It can buy time for carbon controls to take effect.

In the past decade, the world production of beef has grown from 55 to 60 million tonnes and Chinese consumption per person per day has gone from 5 calories to 28 calories — unlike the Indian consumption with is unchanged at 10 calories per day.

Geoff Russell geoffrey.russell@gmail.com

[1] John Houghton. Global Warming: the complete briefing. Third Edition. Cambridge University Press, 2004.

[2] James Hansen and Makiko Sato Greenhouse gas growth rates. Proc. Natl. Acad. Sci., 101(46):16109–16114, 2004.