Reuters: Wall Street was supposed to become the capital of a global carbon trading market worth a trillion dollars a year but now many who thought green trading desks would be the next big thing are fearing the pink slip. US banks had looked forward to a huge “cap-and-trade market” a system where companies would buy and sell the right to emit gases blamed for warming the planet. Many hired carbon traders, picked up assets, and trained members of energy desks to deal in emissions …