I’m barely 10 minutes into a tour of Forked Lightning Ranch when my host, oilman Scott Sheffield, shouts “snake” and leaps to usher me away from the reptile slithering across his manicured lawn.

Bountiful wildlife attracted Sheffield and his wife Kimberley to buy the 2,300-acre property in San Miguel, New Mexico, from actress and fitness guru Jane Fonda just over a decade ago. The Pecos River flows across the ranch, while elk, deer, bears and mountain lions roam the desert landscape. River House, the 9,500 square foot main residence, is a world away from the oilfields of Texas and New Mexico, where Sheffield founded Pioneer Natural Resources in 1997. Along with George P Mitchell and Harold Hamm, he is considered one of the fathers of America’s shale revolution.

Sheffield, who grew up in Iran, says: “We’re warming, I see it here in this ranch.” He believes in climate change but criticises “fanatics” on both sides and says he cannot tell whether its long-term effect will come in 100 years, 1,000 years or 2,000 years. Local average temperatures hit 83.1F this August, up from 75.5F just under a century ago.

In 2023, Sheffield sold Pioneer to Exxon Mobil for $60bn. He still sits on corporate boards, including Tamboran Resources, backed by his son Bryan, and is publishing From Tehran to the Permian.