I wrote about the cap and dividend climate strategy several times in January when it was floated by Peter Barnes, a pioneer in socially and environmentally focused investing. Mr. Barnes says the only approach that guarantees deep cuts in carbon dioxide emissions is to sell a steadily declining number of permits to emit the gas — forcing polluters to pay the full cost of using the shared atmosphere — and returning the revenue to citizens in a streamlined way, as in the Social Security system. [...] In Dr. Hansen’s approach, a straightforward rising tax is imposed on the carbon content of fuels, instead of Mr. Barnes’s notion of a shrinking supply of purchased, and traded, permits. But the basic concept, making polluters pay while shielding consumers from rising costs, is the same. [...] This morning, I asked Mr. Barnes for his reaction to Dr. Hansen’s hybrid. He said it was great. “Whether a tax or cap, it amounts to the same thing in terms of the impact on prices” of fossil fuels, he said. “In the end, Congress will choose, and I think they’ll choose a cap.”Read the full article here.