"Carbon Credits" may be presented to fulfill a fantasy of tree hugging hippies (I mean that in the nicest sense possible), but in all reality it is the greatest and most destructive grab for power in human history. Despite all of the negative press associated with modern living (pollution, crime, inequality, etc.), people are living longer, better lives, everywhere (except for the few places that are still practicing early 20th century communism such as North Korea and Cuba, and even Cubans are living longer). Advancements in science and technology are moving a long at break neck speeds (relative to any other time frames outside the 20th century), and all of these advancements are built on proceeding advances.
Carbon Credits attacks the basic blocks that made the progress of the 20th century possible; access to cheap electricity and cheap petroleum. While its true both of these sources of fuel have negative qualities (pollution, danger of extraction, storage, etc.), they have gone a LONG towards connecting the world, and improving the quality of life; everywhere. Once "carbon credits" begin to dramatically increase the scarcity for these two life blood components of modern life, things are going to change, and not for the better.
Betting on "breakthroughs" in "green xyz" is a bad strategy. How are people going to come up with great new inventions when they can no longer afford electricty? Or when Universities have to increase the cost of admissions because the price of utilities has "necessarily skyrocketed", who is going to be able to attain a degree? There will be those who can afford to, but history has shown repeatedly that those who have money and power really have no reason to try to change the world... because the world is already working in there favor. From Edison to Bell, many of the great innovators and inventors have come from humble origins to change the world. While their inventions may have change the way the world lives, the businesses that they created have grown large, and stagnant, but provided mediums which helped lift other inventors to prominence years down the line.
This carbon credit scheme is not going to favor the Bells and the Edisons before they were rich. Carbon Credits are going to favor the AT&T's, the Goldman Sachs, and the Enrons of the world, while creating a barrier to entry so high that no new businesses will come into being, and the ones that exist will be "too big to fail".