In the 1980s, a press release writer for an environmental group pulled a metric for meat and fossil fuel usage out of the air. It made its way into a book written by an activist and ever since then the concept of 'embedded' emissions has been used by anti-meat proponents.

"It takes a gallon of gas to make a pound of beef" is easy to remember. It is elegant. It is also completely wrong. Regardless, the virtual environmental cost of meat became a craze and it was soon followed by virtual water. The virtual water in the grain in just one part of Egypt is more than all of the water in the Nile so the concept falls apart rather quickly when it comes to the real world but scholars are still broadening the concept out to new areas.

Since China, the world's largest polluter, is now allowed to emit new CO2 unchecked until 2030, thanks to a secret deal with the US government that has environmentalists cheering, it is better to focus on nitrous oxide and methane to make the case that meat is bad - cow burps could be virtually ruining the planet.

Climate models suggest that global emissions of CH4 and N2O account for approximately 27.7% of total radiative forcing since the pre-industrial era, and, in 2001, estimates are that livestock accounted for 25% of that. If so, direct emissions of CH4 and N2O from livestock worldwide represent approximately 9% of total greenhouse gas emissions.

CH4 is emitted into the atmosphere as a by-product of the normal digestive system of ruminant livestock, and is also produced alongside N2O when the components of manure are broken down by bacteria. Suspending disbelief that any broad set of methane and nitrous oxide parameters can be created, their model found that virtual emissions in beef, chicken and pork have increased by 19% over the past 20 years. That could lead to virtual global instability because a large number of countries could be contributing to the virtual production of emissions in another country. Virtual geopolitics is complicated.

Next to CO2, Russia is the big bad guy on the world stage, and so Russia was singled out as the biggest importer of embodied emissions in meat over that period, consuming more virtual emissions than it produced, and receiving the majority of its virtual emissions from Brazil and Argentina.

The estimates also showed substantial internal trade flows of virtual emissions between European countries. Countries are trading virtual emissions all over the place.

Will this lead to a craze in consumption-based accounting for emissions? A West Virginia Democrat once took a rifle and shot a hole his president's cap-and-trade bill for CO2 because it was going to hurt his union coal miners. Imagine if Kansas City and Wisconsin and Texas ranchers all start getting bills from the EPA for their virtual emissions and are told they have to collect from the states where they sell meat.