The Big Questions for Big Oil

From the current issue of the Economist - The Oil Conundrum:

"Big oil firms would then face some existential questions.  In the future, should they carry on as before, splurging on expensive vanity projects in hard-to-reach places, at the risk of having "unburnable" reserves as environmental concerns mount?  Should they reinvest their profits in profits in shale or in greener technologies?  Or should they return profits to shareholders, as some tobacco companies have done, making the beginning of the end of the fossil-fuel era?  Whatever they do, the era of oil shocks is far from over."