I have a prediction: Sooner than you might think, this will be a vegetarian world. Future generations will find the idea of eating meat both morally absurd and logistically impossible. Of course, one need only look at the booming meat industry, the climbing rates of meat consumption in the developing world, and the menu of just about any restaurant to call me crazy. But already, most people know that eating red meat is bad for their health and harmful for the planet. It's getting them to actually change their diet that's the hard part -- and that's exactly why it won't happen by choice.

Going by the numbers, eating meat is pretty hard to justify for the even moderately health-conscious. A National Cancer Institute report released last March found that people who ate the most red meat were, as the New York Times put it, "most likely to die from cancer, heart disease and other causes." The biggest abstainers "were least likely to die." Those who eat five ounces of meat daily, (the equivalent of one and a half Quarter Pounders or Big Macs) increase their risk from cancer or heart disease by 30 percent compared to those who eat two-thirds of an ounce daily -- a stark difference.

The environmental impact is also crystal clear -- and similarly appalling. "Livestock's Long Shadow," a 2006 report by the United Nations' Food and Agriculture Organzation (FAO), found that livestock is a major player in climate change, accounting for 18 percent of all greenhouse gas emissions (measured in carbon dioxide equivalents), or more than the entire global transportation system.

The obvious solution to both health and environmental disasters is to stop eating meat altogether. But this is easier said than done. Even the studies addressing the impact of meat on the planet downplay vegetarianism, as if the authors are nervous to press it on people. Going veggie is not even proposed as one of the FAO's "mitigation options" (which instead include conservation tillage, organic farming, and better nutrition for livestock to reduce methane gas production). Nor is it emphasized in "Happier Meals: Rethinking the Global Meat Industry," a report by Danielle Nierenberg at the Worldwatch Institute. The study's author is herself a vegan, but she told me, "Food choices are a very personal decision for most people. We are only now convincing them that this is a tool at their disposal if they care about the environment."

She has a point: Giving up meat is tough, and arguing people into it is probably a losing proposition. Even with all the statistics out there about the dangers of meat, there are fewer vegetarians in the world than you'd think. A Harris poll conducted in 2006 for the Vegetarian Resource Group found that only 2.3 percent of American adults 18 or older claim never to eat meat, fish, or fowl. A larger group, 6.7 percent, say they "never eat meat," but often that means they only avoid the red kind. Worldwide, local vegetarian societies report high participation in just a few places - for example, 40 percent in India, 10 percent in Italy, 9 percent in Germany, 8.5. percent in Israel, and 6 percent in Britain.

So how will we become a vegetarian planet? The numbers suggest that we won't stop eating meat simply because it's "the right thing to do." People love it too much. Instead, we'll be forced to stop. By 2025, we simply won't have the resources to keep up the habit. According to the FAO report, 33 percent of the world's arable land is devoted to growing crops for animal feed, and grazing is a major factor in deforestation around the world. It's also incredibly water-intensive. The average U.S. diet requires twice the daily amount of water as does an equally nutritious vegetarian diet, reports the Worldwatch Institute. Meanwhile, there will be more than 8 billion people on this earth, and two-thirds of the world's population will live in water-stressed regions.

Sounds like a mess -- and one that doesn't bode well for our cattle cravings. Meat will disappear -- except as a luxury available to few -- and the ethical issues will evolve, too. In the way that slavery, once a broad social norm, later became an unthinkable crime, we can expect to see a similar shift once meat-eating disappears from our planet. Perhaps, some day, the very idea of eating animal flesh will seem as remote as the idea of owning humans does now. So if you're a carnivore, enjoy now -- before the inevitable vegetarian revolution begins.

Jim Motavalli is a senior writer at E/The Environmental Magazine.