A central authority would effectively ration energy by making regular quotas for energy consumption and then issue the appropriate number of carbon currency units to all citizens. These currency units would be non-transferable and would expire within a relatively short period of time, thus prohibiting the accumulation of private capital. It would in effect put the majority of the population back on the feudal manor, where they would live on whatever the feudal lord decided to grant them, with no independent means of subsistence whatsoever. Only in this case, the 'feudal lord' would be an authoritarian world government.
Such a society would be to the advantage of the financial elite, as it would enable them to permanently dominate the world economy through issuance of this currency to suit their interests. Nations could be denied or supplied, as well as individuals, depending on their degree of compliance with whatever agenda the ruling authorities might be pushing. Production and real economic growth would finally be under the direct and absolute control of high finance. We have been moving in that direction for a long time through the activities of Wallstreet/London and the IMF, designed to stifle the development of any economic power and potential rival in the third or second world independent of the markets which they control. Wallsteet/London's control of most of the world's oil reserves and of the world reserve currency in which oil is priced has thus far been the basis of the cartel's power over economic development or the lack thereof - though control by law of all energy consumption through truly global authorities would be yet more effective.
An early advocate of this energy credit system was M. King Hubbert, also the creator of the so-called Hubbert Peak: i.e. the concept of peak oil. What is likely to happen at peak oil? There are only two options, assuming there won't be total systemic collapse: 1) nations and economies transition as rapidly as possible to the exploitation of new energy sources (esp. nuclear), or 2) the world enters a gradual but permanent decline in available energy and therefore in economic activity, societal complexity, etc.
Consider what the reaction to peak oil might be on the part of a global financial syndicate that owes its power to control of world oil reserves and of the currency in which oil is priced. Certainly this cartel would resist option 1, as it would entail the abandonement of the precious resource, control of which is the basis for their power. Option 2 is in efffect the policy which the establishment has persued since the First World War: i.e. prevention of real economic growth in the world - through IMF austerity policies, denail of investment capital, wars, etc. - to prevent the rise of any potential rival.
Consider that the financial establishment's activities - in the 70's esp. -are largely responsible for the failure of most nation's in the world to adopt nuclear power, the only truly viable alternative to fossil fuels. What I am implying is that this cartel has no interest in the world developing new energy sources, for the very simple reason that, unlike petroleum, the likely new energy sources - esp. nuclear - would not be as easily cornered and controlled by high finance. If for example the technology was developed to efficiently extract fissile materials from seawater, to be used in nuclear power generation, every nation on the planet with a coastline could become energy independent: i.e. no longer dependent on the world energy markets, which are dominated by Wallstreet/London. Economic rivals to the cartel would develop, the petrodollar would lose its power, and the cartel along with it.
A solution to their problem would be to acquire the legal right to issue a new currency based on all energy, not just oil. By issuing this currency they would be able to dramatically influence world economic development just as they did previously with control of oil. This parasitic system would be able to increase it's relative influence, albeit in a world shrinking in absolute terms due to the parasites depredations. This trend, as mentioned earlier, is already in progress and has been for some time; though the industrial power of the US and UK has collapsed due to the activities of high finance, that same financial establishment has managed to maintain its power in spite of the loss of domestic industry, by stifling industrialization globally. It's a zero sum game - the cartel wins because it gains a greater share of a shrinking pie.
A good article describing the basic structure and history of the idea of a carbon currency:
Carbon Currency: A New Beginning for Technocracy?