It's been a tough couple of years for Big Oil. Battered by plunging prices, the oil majors have seen their profits sink and their prospects darken. BP lost $3.3 billion in 2015; Shell lost nearly $7.5 billion in the third quarter of 2015 alone, its biggest loss in a decade. Even mighty ExxonMobil saw its profit shrink by half in 2015 from the previous year. The usual oil company response to a period of shrinking profits is to rein in new drilling, cut costs, and wait for prices to rise again. And recent months have seen a modest recovery in oil prices.

But a new report from the influential U.K. think tank Chatham House says the old playbook isn't going to work this time. The problems go way beyond rock-bottom oil prices, and they are unlikely to vanish in a hoped-for recovery. The oil majors, the report says, "cannot assume that, as in the past, all they need to survive is to wait for crude prices to resume an upward direction. The oil markets are going through fundamental structural changes driven by a technological revolution and geopolitical shifts," and the business model that has worked for the last quarter-century is broken.