The growing world population and increasing competition among industrial, agricultural and urban demands for water are contributing to our global water crisis, recognized in 1993 with the establishment of World Water Day. This crisis is further magnified by climate change and the instability of hydrological patterns, which is motivating governments, industries, and individuals to find ways to conserve water. Today, one billion people do not have access to clean water and the Food and Agriculture Organization of the UN predicts that by 2025, two-thirds of the world’s population will live in water-stressed areas where water availability is less than 1,700 cubic metres per capita per year. The challenge the world faces is how to maintain food security without further depleting water resources and polluting ecosystems.

Of the many activities individuals can modify to conserve water — from gardening to cleaning to washing — adjusting our diet carries the greatest potential impact. Globally, the livestock industry uses 50 per cent of the world’s freshwater resources. If the current world population at 7 billion were to adopt North America’s meat-based diet, it would require four planet earths to support this demand. With this impossibility, how will we produce enough food for everyone if meat-based diets prevail when we reach 9 billion in 2050?

Water scientists at the Stockholm International Water Institute indicate that if the western diet of meat and dairy continues, there won’t be enough water to produce food for everyone by 2050. They stress that the world’s population may need to adopt a plant-based diet to avert “catastrophic” shortages. In particular they indicate that, “there will be just enough water if the proportion of animal-based foods is limited to five per cent of total calories.” In North America, animal-based foods represent up to 30 per cent of an omnivore’s total calories. The average annual meat consumption per person is 123 kilograms for the U.S. and 99 kilograms for Canada, more than twice the world’s average of 47 kilograms. Clearly there is room for improvement by countries with heavy meat and dairy consumption.

Because the livestock industry is so water-intensive, the most significant contribution to water conservation that individuals can make is to adopt a plant-based diet. Consider the following: It takes 300 gallons of water to support a plant-based diet for one person for one day, compared to 1,200 gallons for a lacto-ovo vegetarian, and 4,000 gallons for an omnivore. Thus, an omnivorous diet requires 10 times the amount of water compared to a plant-based one. What other single activity in our personal lives can produce a savings of 3,700 gallons of water per day per person? Then consider the aggregate effect when multiplied by millions of people every day.

Let’s examine this further. It requires 2,500 gallons of water to produce one pound of beef versus 25 gallons of water for one pound of wheat. That 2,500 gallons is equivalent to taking a seven-minute shower every day for six months, all for just one pound of beef. Hence, a meat-based diet demands egregious and inequitable amounts of global freshwater resources to feed the eating habits of developed nations, with devastating costs to the environment and the world’s hungry, not to mention the suffering and death worldwide of 64 billion land animals annually. The actual cost of one pound of beef includes 2,500 gallons of water, 16 pounds of grain, 40 pounds of animal waste, and the greenhouse gas equivalent of driving an SUV for 40 miles. In addition, the environmental production costs are potentially inequitably borne by people living far from the consumer of that pound of beef.