The World Bank has estimated that by 2050 demand for water in India will exceed all available supplies, which is bad news for everything including its putative bioethanol production. Up to 400 cities in China are facing water shortages, to the extent that grain production in this most populous nation is millions of tonnes less than it could be or needs to be. Indeed, it may well prove to be water that is the defining resource in determining the limit of China's unprecedented growth, rather than oil. Nonetheless, the projected dearth of oil has encouraged plans to produce biofuels as an alternative to meet China's anticipated rising fuel demand. However, as I have calculated for the U.K., and alluded to for the U.S., there arises a straightforward competition between growing e.g. corn for food or for ethanol production. And surely in countries like India and China where it is already difficult to provide enough food for everyone, how can it make sense to engender further compromise of the resource by fencing-off crops from its food-agriculture?
In the U.K. the main resource dearth is in arable land - we can irrigate what crops we grow, but even if we grew no food and produced entirely sugar-beet for bioethanol production, there is only sufficient land available to provide perhaps one fifth of current fuel usage. Draining water supplies to their limits is very bad from an environmental standpoint, even well before they are exhausted. In a slightly different but related context, when the Armenian nuclear power station was closed following the 1988 earthquake there, an enormous pressure was imposed on other means and resources to make up for that almost 50% of the nation's electricity that it provided. This included hydroelectric power made using water taken from the main freshwater lake, Sevan where the drop in the level of its waters impacted disastrously on the ecology of the region. When rivers are diverted or drained, wholesale desertification can occur as in the Aral Sea, much of which is now down to dry-bed.
Every resource consumes one or more other resources, and so e.g. producing bioethanol, cracking tar sands and forcing oil out of the ground by enhanced recovery methods all dictate demands on other forms of energy such as gas, and all are volume-intensive in terms of the amount of water they use. Sugarcane growers are projecting the advance of their industry, which consumes more water than any other in the world, and even though there is no official world-market for water as a commodity, it does not mean that a price will not need to be paid, in various ways. I have heard it said that future wars will be fought over water, and I can find no reason to disbelieve that. However, since within 15 years there will only be about half the world reserves of oil left, I am anticipating conflict at least at the level of national economies, even without out and out wars being waged. Some have argued that the military strife in the Middle East (Iraq and Afghanistan, so far, with possibly Iran coming under that umbrella of assault) has the securing of oil resources as an underlying cause.
Ethanol plants in Minnesota consume around 3.5 - 6 gallons of water per gallon of ethanol that they produce from corn. It is predicted that, for the U.S. as a whole, from 1998 to 2008, there will be recorded a 254% increase in the volume of water used for ethanol production, and while the U.S. (and Europe) has plenty of water, that cannot be said for the rest of the world. The true measure of the price of water may come when a barrel of ethanol is more expensive than a barrel of oil, once the resource has been squeezed to the point of uncompetitiveness. But to even contemplate pushing the industry toward this situation is ridiculous, because in reality only a very small proportion of the fuel for each nation can be supplied in the form of bioethanol or indeed other biofuels. The solution to the pressing and immediate problem of short oil-supplies must be found elsewhere.