Harvard Business School historian Nancy Koehn joined Boston Public Radio on Wednesday to discuss Amazon CEO Jeff Bezos' newly announced $10 billion pledge to combat climate change. In 2018, Amazon emitted 44.4 million metric tons of carbon dioxide and many Amazon employees have called on the company to reduce its carbon footprint.

"It's a personal pledge — [Bezos] is not making it through a foundation and he's not making it through Amazon," Koehn said. "It's 7.7% of his net worth."

Koehn said she thinks the timing of his pledge should be taken into consideration.

"$10 billion is an extraordinary amount," she said. "It'll be hard to figure out how to use that money as effectively as possible, partly because it's so much and partly because the infrastructure of climate change action is still emerging."

Koehn is a historian at the Harvard Business School where she holds the James E. Robison chair of Business Administration. Her latest book is "Forged in Crisis: The Power of Courageous Leadership in Turbulent Times."