From the Guardian (Dominic Waughray):
Currently about 70% of the world’s freshwater withdrawals are for agriculture, 16% are for energy and industry and 14% are for domestic purposes. Recent work suggests that unless we change our historic approach to how we use water, we could face a 40% gap by 2030 between global demand and what can sustainably be supplied. Why is this, and what are the implications?
To meet the forecast growth in demand for food over the next 20 years, farmers will need to increase production by 70-100%. Changing diets will increase demand for meat and dairy products in particular. A kilogram of meat requires up to 20,000 litres of water to produce (compared to about 1,200 litres to produce a kilo of grain), and global demand for meat is forecast to increase 50% by 2025. Herein lies the water challenge. If we already use over 70% of freshwater withdrawals for agriculture and face an increase in demand for food by 70% by 2030, especially for water-intensive meat and dairy, it is clear that a business-as-usual approach is not an option. We cannot use over 100% of our freshwater for agriculture. Significant, perhaps radical changes in agricultural water usage will be required.
At the same time, our demand for energy will also grow; and energy is also a thirsty sector. The International Energy Agency forecasts that the world economy will demand at least 40% more energy by 2030. McKinsey and Company estimates that 77% of the power stations we will need by then have yet to be built. By that year, China will need to expand its power generating capacity by over 1,300 GW (1.5 times the current level of the US) and India by 400 GW (equal to the current combined total power generation of Japan, South Korea and Australia). Increasing access to energy is a priority for many countries. 1.5bn people in the developing world still lack access to electricity and over 3bn rely on biomass for heating and cooking. Yet, energy needs a lot of water. In richer countries, up to 50% of freshwater withdrawals can be used in the production of oil, gas and electricity…
Many countries are extracting groundwater faster than it can be replenished (Mexico by 20%, China by 25% and India by 56%). Over 70 of the world’s major rivers now hardly reach the ocean due to the extensive diversion of water for human use. If current trends continue, by 2030 increasing water scarcity could cause annual grain losses equivalent to 30% of current world consumption (just as we need 70% more food). As demand continues to grow, competition for water will intensify between economic sectors, as well as between geographies.
Thanks to Loretta Lohman for the link.