Craig Cohon has had an unusual career. The 59-year-old Canadian helped bring Coca-Cola to Russia in the early 1990s and co-owned Cirque du Soleil in the country. He once managed an opera singer and has worked for the World Economic Forum.

Those decades of globetrotting took their toll on the planet. When Cohon decided to calculate his lifetime carbon footprint, factoring in everything from his adult travels to his childhood diet, he pegged it at 8,147 metric tons of carbon dioxide equivalent — 28 times the global average.

"I feel like I am 100% accountable and 100% guilty of my personal damage to the world, and I’m 100% not to blame, because I was unaware at a deep level of the unintended consequences,” Cohon said. "But now that I understand it I am doing something about it, personally.”