As delegates gather today in the South African city of Durban for the latest round of international climate talks, hopes have all but faded that the assembled negotiators will clinch a comprehensive deal to replace the Kyoto Protocol, which expires at the end of next year.
After the last high-profile climate summit in Copenhagen two years ago failed to reach an agreement, the prospect of another failure in Durban is prompting calls for developed economies to act unilaterally, reducing their own greenhouse gas emissions while imposing carbon duties on imports from countries that refuse to set limits on their own emissions.
This might initially sound like an attractive solution to the problem of growing greenhouse gas emissions. The Kyoto talks collapsed largely because China, the world's biggest emitter of greenhouse gases (see the first chart below), not only refused to accept any ceiling on its own emissions, but objected to developed economies setting limits on theirs, lest they set an awkward precedent.
The supporters of carbon duties argue that Beijing's refusal to limit its emissions gives Chinese companies a powerful advantage over competitors in countries where companies must bear the cost of reducing their own greenhouse gas output.
As a result, they are calling for the imposition of 'border tax adjustments', which would slap punitive tariffs on imports from countries which have undertaken no emissions reductions of their own.
This, they claim, would benefit the global environment by transferring some of the cost of emission reductions onto countries that refuse to limit their own greenhouse gas emissions.
The potential impact on China's exporters would be enormous.
