Once production of conventional crude peaks, we increasingly as a society will have to make choices between maintaining our energy supply, or choosing policies that increase the impact on climate and decrease environmental health.
This seems like a reference to coal and tar sands. But it's not an either/or, it's an if/must. It's not on one hand we have maintaining our energy supply, and on the other hand we have environmentally problematic energy sources.  It's that we must pursue environmentally problematic energy sources if we are to continue to maintain our energy supply.
Those tradeoffs are what need to be discussed. Some would argue that we can reduce our demand and meet such reduced demand with sustainable biofuels. I am not such a person, but I do strongly urge that an apples and apples framework be circulated so that decisionmakers dont rush pell mell into an energy scheme that gives us an immediate boost with a long term noose.