Just 3% of the planet’s water is fresh water, two thirds of which resides in polar ice and glaciers.

The growth in global water demand over the last 100 years has run at twice the rate of population growth. The world population is expected to increase from its current level of 7 billion to over 10 billion by 2050 whilst, in the UK, the population is forecast to rise from around 65 million currently to over 74 million in 25 years’ time.

If consumption levels remain at today’s 150 litres per person the demand on water will be unsustainable; in some countries, for example Qatar, water is now more expensive to buy than fuel. it is easy to understand why the World Economic Forum has ranked the world’s anticipated water crisis as our most significant long term global risk.