A lot has changed in the past several years that have shifted companies' focus toward sustainability.

Post-9/11, post-financial crisis, post-BPA and melamine scandals, the public opinion pendulum has swung strongly toward a more activist role for governments and corporate boards in overseeing how companies operate globally.

If this is the "new normal," future business leaders have to be prepared to deal with these complex issues -- not as matters of public relations but as integral parts of operational strategy.

But business education programs, even green MBA programs, are failing to prepare students for the deep, complex and sticky issues that underlie sustainability strategy. In narrowly focusing on topics like cap-and-trade and carbon footprint reduction, business education has left uncovered the hidden, human dimensions to sustainability -- an exclusion that is leading to a major void in the sustainability efforts at companies across the globe.

According to recent research from Harvard Law School and the IRRC, only 28 percent of global companies have in place labor and human rights (LHR) policies covering their global supply chains. And for most green MBA and sustainability programs, human rights are too politically charged to warrant a place in the coursebook.

We argue that sustainability is not merely a series of financial decisions, but a complex web of social, environmental and economic ecosystems in which global companies need to operate in order to create long-term success and profitability. And the human elements of those systems, including working conditions, access to clean water and education, health care and other related issues, should be central to businesses' sustainability strategies.

To incorporate these complex issues into the curriculum, business schools must make a shift away from process thinking and into systems thinking, and take a more scientific approach to business education. They must help students make this radical shift in thinking by offering courses and projects that shift the way their analytical minds work.

Business schools are very good at asking students to ask hard questions -- for example, how would marketing, IT and operational functions work together to reduce a company's energy consumption?

Traditionally, we are not so good at asking students what the questions should be, in the first place, or how the systems within and outside a business support or conflict with a company's mission and goals. A cross-functional team to address energy consumption will have little long-term impact if, for example, a citywide shift to wind power is imminent, or if all employees drive individual cars to work, or the company's widget manufacturers in Asia employ child labor.