Digging around a bit more, and reading the report forwarded by Joyce has been very instructive. The thing that makes having a no-meat diet so obvious is the economics of the problem, and the solution is simple. The reporting of reducing greenhouse gases has so far been about how much it is going to cost the average consumer. The report points out that the proper accounting of livestock production needs to also take into account the transport and storage costs that are also involved, which results in a staggering 159.03 Mt CO2-e, (1990 and 2004 figures - I need to update to 2005) which accounts for 31% of all of Australia's emissions.
Taking the current price of a CO2 as about 22 euro (http://www.co2prices.eu/) this would make the current market value of the CO2-e of livestock as about $5,985,523,200 AUD( 1.7111 AUD = 1 Euro today) or about $6 billion AUD. Since the livestock council submission to the Garnaut report says they are a $6.1 billion AUD industry, it adds up to about zero. In other words, livestock taking into account greenhouse gas emissions, has no value.
Now here is the good bit; with no livestock in Australia, we would reduce CO2-e by 31%, which gets us a long way to our Kyoto objectives. Furthermore, this could be done by consumers in Australia spending less instead of more. It will save you money. All other strategies are about increasing the cost of items to include their CO2-e cost, but it is so hard to reduce consumption of electricity, fuel etc without significant lifestyle changes. Vegetarian diets are cheaper than meat diets already, and with CO2-e costs included the cost difference will be even greater.
So, not all greenhouse reduction strategies are about costing consumers more. Vegetarian diet will cost less.