When the idea of sustainable investing was born in the 1960s, it was a vehicle for supporting companies engaged in environmental and social good at a cost to their bottom line. Today, sustainability is measured in terms of environmental, social, and governance (ESG) issues-essentially, a company's green footprint. Sustainable investing is now a major driver of capital and corporate priorities. In fact, many companies now consider ESG a key component of their brand-protecting the planet, drawing investors, engaging employees, and engendering customer loyalty.