If people really care about global warming and economic activity, they should read the latest IPCC report. It says that the best way to avoid warming is economic development. If the economy freezes in place (something a high carbon tax could do) then the warming will be about 4C by the end of the century. If the economy in all the "third world" countries develops into something like first-world conditions by the continued march of progress, then the warming will be closer to 1C.
Anything that stands in the way of that development is going to contribute to the warming. Removing these tariffs is a good thing, but to get maximum environmental benefit they need to get rid of the rest.
I know, Overton's Window and all.