Green Banking

Rather than simply considering whether a prospective borrower's business contributes to climate change, banks are slowly turning their attention to making sure borrowers in a variety of industries account for how climate change could affect them.

For William Thomas, sustainability is a constantly evolving mission. The early targets — energy, waste, paper and employee involvement such as reduced air travel — have mostly been achieved. Some of the bank's steps will require a different approach.

The philanthropic arm of Wells Fargo is working with the Department of Energy's National Renewable Energy Laboratory on an incubator that grooms early-stage clean technology startups and validates their products.

It's not glamorous, but a tool that measures the bank's energy use has helped it reduce consumption by 17% over the past five years.