All of us may be forced to become vegetarians this century, according to scientists at the Stockholm International Water Institute.

In a report issued this week, Sweden’s water scientists said, "There will not be enough water available on current croplands to produce food for the expected 9 billion population in 2050 if we follow current trends and changes towards diets common in western nations."

Animal-based foods currently make up about 20 percent of humans daily protein intake. But the Swedish report says the world’s population will have to cut that figure to 5 percent by 2050 to accommodate the planet’s "considerable regional water deficits."

Despite increasing per capita food production, the Swedish report says, "Nine hundred million people already go hungry and 2 billion people are malnourished. With 70 percent of all available water being in agriculture, growing more food to feed an additional 2 billion people by 2050 will place greater pressure on available water and land."

Their answer to the dilemma is for vegetarianism to increase. The scientists believe more vegetarian diets could help free up large portions of arable land to human food production.

The report was released for the start of “Water Week” and the annual world water conference in Stockholm.

The idea that water shortages will force changes to livestock production is not new, however.  Three years ago Drovers/CattleNetwork columnist Suzanne Bopp noted that “for years, outlandish claims have been floated about the amount of water cattle production requires. Producing a pound of beef is said to take anything from 2,500 gallons of water to as much as 6,000 gallons (according to Stanford professors Paul R. and Anne H. Ehrlich in their book Population, Resources, Environment). Newsweek once reported that the water required by a 1,000 pound steer over its lifetime ‘would float a destroyer.’”

Bopp wrote that U.C. Davis animal scientist Jim Oltjen found that a pound of beef “actually requires 441 gallons of water. NCBA uses his research to answer claims of egregious water waste in the beef industry, as they do at length on their Web site,”

Still sound like a lot of water? The website says a pound of rice requires 403 gallons of water and a pound of chocolate needs 2,847 gallons.

“And while half our water does go to agriculture, of course it’s not the case that all, or even most, of it is going to grow feed for livestock, as some have claimed,” Bopp wrote. “Research published in the Journal of Animal Science concluded that our total livestock production took just about 11 percent of our water. The water to grow crops that become livestock feed was 9.7 percent of all water use; livestock consumption, at 1.2 percent of water use, made up the rest of the total.

“As for the floating destroyer claim, the NCBA Web site puts that to rest as well. They use the U.S. Navy’s report that a destroyer needs about 2.11 million gallons of water to float. As we’ve learned, it takes 435 gallons of water to create a pound of boneless beef. If a steer weighing 1,000 pounds yields 450 pounds of boneless beef, that means it needs a total of 195,750 gallons of water  —  which would leave the destroyer high and dry.”