ExxonMobil Holdings Corp. plans to invest more than $100 billion over the next few years to help augment global energy supplies, Chief Executive Officer Darren Woods told CNBC after the supermajor posted blockbuster quarterly results.

Warren Buffett’s Berkshire Hathaway Inc. reached a deal to buy Occidental Petroleum Corp.’s petrochemical business for about $9.7 billion in cash.

The world has spent a decade gorging on fuel from America’s shale basins, and oil prices are topping $100 a barrel. So it might seem an odd time to be contemplating the energy transition. But that's precisely the task facing the small towns across places like Texas, Wyoming and New Mexico: deciding when to move on from their bedrock industry, even when it’s in an upswing.

It will go down as the wildest of the shale wildcatters, the overreaching pioneer of fracking techniques that minted vast fortunes and, now, have left behind ruin.