Carbon pricing: climate injustice?

During COP21, many experts have advocated the need for a global carbon price. However, for Olivier Godard, this measure, which does not take inequalities in economic development into account, is unrealistic and, above all, inadequate. Explanation.
 
To implement global and therefore single "carbon pricing" some economists suggest merging regional carbon markets into a single world market. This is a not as good an idea as it sounds as it is not compatible with the negotiation process initiated after the Copenhagen COP15 in 2009. I support the idea of setting a price on carbon but not a single price for all countries.
 
The climate is a public good whose quality is determined in a decentralized manner by the emissions of seven billion people. To maximize collective well-being, the willingness of every person to pay for a given quality of this resource needs to be aggregated. This willingness reflects the trade-off between the usefulness of the public good and that of private goods and services that everyone needs to get to survive and develop. Because of the huge differences in situation and income, these trade-offs are very different. In these conditions, wanting a single carbon price would be unfair. An example of this is charging 900 million people who have less than $2 a day the same price as 700 million who have an average wealth of $75,000. To make the single price fair, major wealth transfers would need to be made in favor of the poorest countries.
 
It would also oppose the "bottom-up" approach decided in Copenhagen in 2009. It is up to each Member Country to define its own emissions targets, its transition path and its policy instruments. The local carbon market, if it exists, is one of the means chosen by each government to achieve its own goals. The carbon price that emerges is expected to be the driver of transition. Member Countries wanting to preserve the integrity of their own choices cannot want an international mechanism to impose a different price. A "single world price" would necessarily be too high for some countries and too low for others.
 
Finally, for international carbon quota trade between companies to actually reduce collective costs in an efficient way, taxation of energy input would also need to be similar in all countries. Otherwise, such trade will induce reductions in emissions that are technically more expensive in regions which do not levy much tax on energy at the expense of economic efficiency and the public finances of the countries which levy the most tax on energy input, such as France.
 
On another level, implementing an equal individual right to greenhouse gas emission worldwide is not what is requested by climate justice. One of the requirements of international cooperation is that no country should lose out: even the most emitting countries should get something out of it. There is also a distortion between the instrument (world market) and the rationale (equal individual rights). As the aim is to promote an international market used by both Member Countries and businesses, alibi-individuals will never see these "equal rights". At the end of the day, emitting CO2 is not a fundamental freedom that needs strict equality. Related needs, such as energy needs, vary greatly from one region to another. Gas emissions are a result of global industrial geography, the size of regions, and the state of the infrastructure in each country. The most appropriate criterion would be to periodically distribute a carbon budget in proportion to the "production of goods" component of the gross domestic product of each country".