The Earth is 70 per cent covered by water, but 97.5% is in the sea, and unfit for human consumption. According to the UN, the world's water reserses are expected to shrink by 40 per cent until 2030. On the other hand, demand for water is expected to increase 55 per cent ultil 2050. Suplly will not meet demand. There are a few thing we can make: water treament and reuse are very efficient. However, above all this: use water appropriately.