Lab-grown meat is coming. But growing a burger in a petri dish won't be cheap, at least not at first, says Mark Post, a vascular biologist determined to grow "cultured meat" in his lab. Eventually, though, costs will drop as the process is refined. Then in vitro meat could have a huge economic impact, helping satisfy rising global demand while saving land, water, and energy costs. It could even be a solution to global warming. Here's a look at how the sausage of the future gets made, by the numbers:

The estimated cost to produce the first lab-grown burger. Post says he hopes to accomplish the feat within a year, "just to show it's possible."

The average cost of a McDonald's Big Mac in the United States as of June 2011, according to The Economist

In inches, the length of pale, muscle-like strips Post has been able to grow in petri dishes. Each is a centimeter wide and thin enough to see through.

The number of these artificial meat strips that will be needed to layer together a burger patty 

218 million 
In tons, worldwide annual meat production from 1997 to 1999, according to the World Health Organization

376 million
In tons, worldwide annual meat production estimated for the year 2030 — with demand likely being much higher

34.2 million
In 2010, the amount of cattle counted for U.S. commercial slaughter, according to the USDA

26.4 billion
In pounds, the amount of beef consumed in the U.S. in 2010

Grams of vegetable protein fed to cattle to produce every 15 grams of edible meat from livestock

Percentage of agricultural land currently being used to raise livestock, says Post. "It's simple math. We have to come up with alternatives."

Percentage of global greenhouse-gas emissions contributed by the meat industry, according to a report by the U.N. Food and Agriculture Organization

35 to 60
Percent energy lab-grown meat would save compared to traditionally farmed livestock, according to the journal Environmental Science and Technology

80 to 95
Percent greenhouse-gas emissions lab-grown meats would save versus conventionally produced animal meat

Percent land lab-grown meats would save versus conventionally produced animal meat

Sources: The Economist, International Business Times, Reuters, USDA