Now that nearly 200 countries managed to more or less agree on a mitigation target and on mechanisms, one might wonder whether there does not exist an easier and more natural route. The starting point is to observe that reducing CO2 emissions essentially means keeping fossil fuels in the ground. This can happen because with stop buying them (demand side approach), or because they stop extracting them (supply side approach). The current approach is purely demand sided, which is why 195 consumer countries had to come to an agreement on lowering their consumption of fossil fuels. On the supply side, 90% of the coal, oil and gas reserves are located in 26 countries. So reducing and phasing out extraction only requires an agreement between these 26. Why would they agree to this, precisely they who are the fiercest opponents of any binding climate agreement? Because they would find an interest in doing so, at least in the short run. Indeed, such an agreement would be like a super-OPEC, a cartel agreement to reduce supply in order to lift prices. And a lift they need. In addition, demand side policies mean for them selling less at lower prices, while a cartel means selling less at higher prices.
Why would we let them form a cartel? We would not, if there were another credible way to rapidly lower fossil energy consumption worldwide. There is not, so the good old price mechanism is the best way forward. Of course, the revenues of fossil energy countries would soar in the short run, be we would hope that they invest those revenues towards surviving after full phasing-out of extraction. And we would not have to compensate them for keeping the fossil stuff in the ground, a silly idea to begin with.
In terms of implementation, a supply side policy is a lot more practical than the current demand side approach. First, it is much easier to monitor extraction and sales of fossil fuels than CO2 emissions. Second, consumer countries' governments could dispense with fighting for carbon taxes and other effective domestic policies to curb fossil fuel consumption: higher world prices would do the job. They could concentrate their efforts on helping those citizens for whom higher energy prices are a threat. And they would know exactly what to do with the USD 100 bn/year they pledged to send to poorer countries: this money would help them face high energy prices by transitioning to efficiency and renewables.