Across the globe, signs of an impending water crisis are readily apparent. Despite the fact that 97.5% of the earth's surface is covered by water, less than 1% of that is suitable for drinking. Of that 1%, 70% is accounted for by agricultural needs, and 22% by industrial demands, and those numbers continue to rise with a growing population whose hunger for food, services and consumer goods cannot be satisfied. By 2075, according to the Stockholm International Water Institute, between 3 and 7 billion people will be living in areas suffering from chronic water shortages. The UN has called the crisis "one of the largest public health issues of our time" (World Business Council for Sustainable Development (WBCSD), 2008). Deepening the crisis is the fact that what water remains for basic human needs is frequently subject to pollution, waste, and inefficiencies that now are compounded by the reality of global warming. Water is, indeed, "the new oil." 

Little wonder, then, that desalination is seen by many as a viable solution to the crisis, with its promise of an unending supply of potable water. Desalination offers a predictable water supply that is not dependent upon regional cooperation, subject to the vagaries of Nature, or compromised by the waste and extravagance of humankind. Indeed, the technology has advanced sufficiently so that for some energy-rich nations, water-starved regions, or specific manufacturing needs, it makes sense. For the vast majority of people's needs, however--whether they are nations, businesses, farmers or localities--there are better options. 

The principal objections to widespread use of desalination are the environmental risks and economic costs. The risks to the environment are by no means clear, and will require further study. However, critics point to the likelihood of fish and wildlife being trapped or maimed by intake pipes, their spawning beds or migration routes being disrupted. They cite the danger of briny waste concentrates--often laced with contaminants--being released into estuaries, deep wells or aquifers, thereby compromising the continued survival of native plants and wildlife. They note the enormous energy costs necessary for converting salt water into fresh, and the negative implications for greenhouse gases and global warming. 

A more practical, economical, and far-reaching approach to the water crisis, many analysts say, would be to invest in conservation efforts, recycling, pollution control, rebuilding the current infrastructure, and developing new strategies for water management. More gain is possible from recycling water - particularly for industrial and agricultural use - from creating centralized treatment and distribution facilities that can monitor water use and quality, than is to be had by desalination alone. 

That being said, analysts point to remarkable gains in efficiency and technology--nanotube filtration, solar or wave-powered processing plants, cogeneration platforms, and advanced membranes that can filter out toxins, microbes, and medical waste - that suggest there is a place for desalination in any responsible water resource management portfolio. According to Global Water Intelligence, over the last five years "an average of 800 new desalination plants have been constructed annually." In 2006 and 2007, "the world's capacity grew 43%, and since 1990 has experienced an average annual growth rate of 17%." The research group notes that "about 14,380 desalination plants operate across the world, with a total contracted capacity of 62 million cubic meters, or 16.3 billion gallons per day." Tom Pankratz, of the International Desalination Association predicts that the "total global seawater desalination market could be worth $25 billion over the next five years and $58 billion over the next ten years" (Boals, 2009).