We splash in it, use it to cleanse our bodies, to grow and cook our food, and to quench our thirst. More importantly, we rely on it to sustain life itself. Water: it's among the most abundant substances on Earth, covering more than 70 percentof our planet's surface.
As it turns out, only about one percent of the world’s water supply is freshwater. The rest of it is saltwater, which isn’t much use to thirsty people or thirsty plants. Researchers continue to search for affordable ways to desalinate (remove salt and minerals from) seawater, but for now we all have to make do with a finite amount of freshwater. This is becoming increasingly difficult, for two main reasons:
1. A growing global population is increasing demand for freshwater in both direct and indirect ways.
2. The effects of climate change are creating a problematic feedback loop of droughts, water shortages, and excessive water usage. Let’s break down these causes one at a time.
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It is estimated that the average American uses about 2,000 gallons of freshwater per day, every day of the year. However, only five percentof this water (about 100 gallons) runs through the taps, toilets, and hoses of our homes. The rest of it is “hidden” in the food we eat, the energy we use, and the products we buy.
Agriculture uses about 70 percentof humanity’s freshwater supply to irrigate fields and grow the crops that feed us directly (vegetables and grains) and indirectly (feed for cows, chickens, and other livestock). It is estimated that it takes 441 gallons of water to produce 1 pound of boneless beef. And the demand for livestock is on the rise. Increasing wealth in places such as China and India is resulting in diets richer in beef, chicken, and other animal-based proteins. Which means the demands on our water supply are increasing steadily.
Agriculture has evolved over millennia in response to relatively predictable water sources and volumes. However, increasingly variable weather systems are starting to become the norm, creating changes in water availability, which is complicating the process of growing crops.
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1. As the Earth’s temperature rises, evaporation increases, which can contribute to drought. This has a compound effect: farmers need more water for their fields at the same time reservoirs are disappearing.
2. Small increases in temperature can cause more precipitation to fall as rain, instead of snow. This means more rain in the off-season, and less snowpack in mountain areas. Reduced snowpack means a loss of snowmelt in the spring and summer—which means there is less freshwater for farmers to use for crop irrigation.
3. Glaciers provide year-round water through melting, but they are disappearing at an alarming rate. Ice sheets—like the one that covers Greenland—are also part of a vicious cycle. When intact, they help cool the Earth by reflecting much of the sun’s heat back into space. As they disappear, this cooling effect slows down, making the atmosphere even warmer.
Modern agriculture is facing many challenges, from many different sources, that are affecting our water supply. This means it is more important than ever that we track, manage, and get the most out of every drop we use. Agriculture needs modern tools to help farmers use water more precisely, by tracking weather data, monitoring in-field moisture levels, and breeding plants that can withstand variable weather conditions.
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