Recently, the idea of a carbon tarif has been floating around as an "aside dish" to the carbon tax. I am somewhat skeptical that such a "dish" would actually be beneficial in the fight against global warming.
Most of the damages done by global warming to poor countries would be because a hotter and more volatile weather would mean high adaptation costs to industries like fisheries, agriculture and certain other natural ressources upon which poor countries depend heavily for subsistence. The decline of such industries could likely lead to the bigger problem of malnutrition. Damages caused by more frequent weather events would also be considerable for these countries. Add to this the issue of increased mosquitos swamps that would increase malaria risks because of warmer temperatures. But here is the deal, most of the aforementionned damages are not caused by climate change per se but more by poverty (a lack of means as Amartya Sen would say).
The idea then is more about development than it is about climate change. Let us be honest, the damages extreme weather events can be contained through good infrastructures. After all, the Thames in London is rarely flooding because there are dykes to control water level changes. But such investments are costly at very low levels of national income. Thus, a green tarif would more likely be detrimental to the poor countries that it would be trying to help by mitigating the effects of global warming. Restraining free trade of goods and services would probably make poor countries worst off to face the effects of global warming while probably not reducing emissions so considerably.
Also importantly, free trade is good for the environment (Antweiler, Copeland and Taylor published several papers on the issue, this paper is the easiest to get). It promotes the adoption of new technologies through economies of scale. These new technologies allow poor countries to leap-frog rather than use the same long and tenuous development path that western countries used thus reducing sources of pollution.
I am willing to debate about a carbon tax, I did previously argue in The Financial Post that it would need to be pretty high to affect consumer behaviour considering the increasing inelasticity of energy (more specifically oil) consumption. However, I believe that the "carbon tarif" would probably lead to litte reductions, at a very high cost while impoverishing poor countries when they need to grow the most.