The company has already made some improvements, and it now only takes 2.54 liters of water to make one liter of Coke, compared with 3.14 liters five years ago, Isdell said.

Drought, rising populations and overuse by industry and agriculture means that by 2025 two-thirds of the world could face a serious lack of water, according to the WWF. More than one billion people have no access to safe water today.

"If the communities around us do not flourish, and are not sustainable, our business will not be sustainable in the future," Isdell said. "If we do not act responsibly, that society will not give us the social license in that broader context to continue to operate."