The little engine that could, and the oil giant that couldn’t

Last December, when a week-old hedge fund named Engine No. 1 challenged Exxon Mobil to change its ways, laughter echoed through Wall Street circles, from the fund’s name that recalled a famous children’s book to its tiny, then-$40 million stake in what was once the world’s largest publicly traded company.

Just six months later, the fund delivered a massive blow that rippled throughout the oil-and-gas industry. Engine No. 1′s campaign forced Exxon to accept new board members who could bring about a reckoning over its business strategy and confront the risk of global climate change…