In the Spring 2016 edition of Catalyst, a periodical of the Union of Concerned Scientists, Nobel laureate and former U.S. DOE head Professor Stephen Chu offers a suggestion on what the world should do after the COP21 meeting in Paris. Below is an excerpt, with emphasis added, and slightly edited for completeness where noted:
More than half of [the allotment of global Carbon emissions needed to have a 50% chance of remaining below the 2°C target] has already been used up since the beginning of the Industrial Revolution and, at our current emissions rate, the remainder will be gone in about 30 years. Clearly, the remaining carbon budget is a precious resource, but cap-and-trade allocations start from existing levels of emissions. It is prima facie unfair to allow developed countries to pollute more because they were historically the biggest polluters.
A global carbon tax avoids the intractable problem of how to allocate carbon emissions credits between developed and developing countries, and levies the highest taxes on the biggest emitters. If countries are unwilling to levy a cost on carbon, the playing field can be leveled with suitable border tariffs on goods imported into participating countries. In addition, the wealthiest countries still need to help less developed countries in this transition.