Sustainability has taken root as a new priority in the corporate landscape. The usual paraphernalia has come with it: sustainability reviews and reports, sustainable practices and products, and-at the top of the tree, the latest addition to the executive C-suite-the chief sustainability officer.

It might look like just another corporate fad. To understand why it's not-and to find out why CFOs should care-it's best to ignore the jargon and instead check the shelves of a supermarket in India's sun-drenched southern states of Tamil Nadu and Andhra Pradesh. Alongside the other detergents is one, Surf Excel, which prides itself on producing less lather than its competitors, while ensuring clothes are just as clean. More lather means more rinsing, which requires more water-and water is one thing that consumers in southern India can't afford to waste.

The region's growing population has put an ever-greater strain on its water resources and each year brings a fresh crisis as reservoirs shrink and the two states feud over their shared rivers and canals. Surf Excel's manufacturer-the global food and hygiene products giant, Unilever-claims that the less-sudsy detergent saves two buckets of water per wash, which could add up to a yearly saving of 14 billion liters.