From Daniel Gros over at vox:
The Commission has estimated that a carbon price of around the €40-50 per tonne would be required to reach the EU’s 2020 commitments. This would imply, at current exchange rates, about $50-70 per tonne. This might be too high for the US, where $30-$40 per tonne has been estimated to be the politically feasible limit. At $40 (€30) per tonne, a border carbon tax on Chinese exports (to the EU) would be a bit more than two times $40 per $1,000 of exports, or approximately 9% on average. Rates would be much higher for energy-intensive products and lower for most others.
Of course, these calculations are based on relative carbon intensity of a country's products. If per capita emissions were being used, the tariff would go the other way (I have not seen specific estimates, aside from this: http://worldtradelaw.typepad.com/ielpblog/2009/10/talking-tough-on-carbon-tariffs.html)
To make this more palatable to developing countries, he proposes the following:
A massive increase in EU tariffs against developing-country exports would certainly make them feel disadvantaged. While global welfare would increase, they might lose. However, there is an easy way out of the political problems. The EU could simply promise to use the proceeds from the tariff to help poorer exporting countries reduce the carbon intensity of their economies.
Now this is interesting. The EU could tax Chinese/Indian imports and then use these taxes to build, say, wind farms in China and India. I wonder if developing countries would go for that.
