There are over 300 million trillion gallons of water on Earth.
There's so much of it, we think of water as an infinite resource.
But only a small amount is suitable for use.
Global Water Supply:
Water covers 70% of Earth's surface
Only 3% is fresh water
Only 1% is available for use
Over a billion people already lack clean drinking water.
And we depend on water for so much more agriculture, energy, industry, and transport.
Yet few realize the uneconomic means by which we consume this valuable resource.
Brian Richter, Director, Sustainable Waters Program (US) - "We may know where the water out of our tap comes from, but we very seldom know where the water that went into our can of Cola or into the shirt that we're wearing on our back, where those goods were produced and how much water it required and what the consequences were for the natural systems in those areas and for the local communities that are dependent upon that same water.
So for example, the cup of coffee that you may have in the morning requires on the order of 120 liters just to produce the coffee and bring it to your table... a hamburger, 8000 liters of water. To produce enough water to grow the cotton in my shirt is 3000 liters as well."
A growing world population means water consumption is increasing.
Over the last century, water use increased sixfold.
Dr Sandra Postel, Director, Global Water Policy Project - "We've gone about meeting these human needs in a very simple way, which is every time we need more water, we go out and find it. We tap another river, we build another dam, we tap more ground water and take more out of the natural world."
These pressures can have a dramatic impact on global water supplies.
Lake Chad, North-Central Africa
Lake Chad, which 30 million people depend upon, has depleted by 90% since the 1960s, due to overuse and climate change.
Severe Water Scarcity will affect:
2025 - most of Africa and West Asia
2050 - 60% of the world's population
Global water shortage could have devastating consequences for us all and could lead to wars over resources.
Conserving existing supply, and reducing demand, is vital if we are to reduce or prevent water scarcity.
So we should all consider our water footprint, before it's too late.