For many years, people who think about these things have posited that lab grown meat could replace meat from animals as food, thus eliminating all of the animal cruelty and environmental issues associated with farming animals for meat. "Cultured meat" could be the choice of future carnivores.
However, making this meat is easier said than done. Growing muscle tissues in a laboratory setting is not an easy task, nor, it turns out, is it cheap. Right now, it requires many man hours and expensive supplies and equipment to grow mammalian cells in culture. Muscle cells, the kind that make up the animal meat we eat, also needs to be stretched or exercised in order to develop into tasty muscle. As an additional hurdle, many in vitro mammalian cell culture systems used by scientists use products made from farmed animals. If laboratory meat is going to be made in a way that does not harm animals, components like this are off the table.
Additionally, if people are to eat this in vitro meat, it would have to taste something like meat from animals, and would have to be comparably priced. That requires some advancements in the methods and technology currently used to grow tissue in culture. In an effort to promote innovation on this front, currently PETA (People for the Ethical Treatment of Animals) is offering one million dollars to anyone who can produce and affordable lab-grown replacement for chicken before June 30, 2012.
Recently, however, there has been some progress toward the production of cultured meat. Dutch scientists have created lab-grown meat from bovine stem cells harvested from a slaughterhouse. The "meat" consists individually grown sheets of muscle tissue, grown in culture using Velcro tabs to stretch the fibers so that they develop properly. Right now, the cost of a hypothetical burger made out of this meat, consisting of hundreds of thousands of sheets of muscle tissue, is estimated at $345,000. That's still a little steep for consumers, but the scientists say they plan to produce one as proof of principle within a year. Since the tissue is grown without a circulatory system, it lacks blood and is white in color, and it also lacks the associated fat of meat from an animal. Currently, the scientists say that improving the taste and color, possibly by adding laboratory-grown fat or blood, are goals that they are working towards.
Proponents say that this meat could replace or supplement modern factory farming as a more sustainable, cruelty-free meat product. However, challenges include making the meat palatable, ensuring that the product appears appetizing, and producing it at a cost where it can compete with farmed meat.
Until your laboratory-grown burger becomes available commercially, if you'd like an environmentally friendly, affordable, laboratory-grown protein, you'll have to be satisfied with mycoprotein (which, as an omnivore, I find quite tasty, even though it's not meat).