The Big Four accounting firms are bringing in talent from Europe to build their sustainability practice in the U.S. and help companies deal with a cap-and-trade scheme.
There's a good article in the N.Y. Times describing the trend and how the passage of the Waxman-Markey bill in the House has really galvanized a lot of companies, and how they're turning to firms like PricewaterhouseCoopers and KPMG to assist them. After all, somebody is going to have to keep track of all that carbon, and who better to do it than an accountant.
A cap-and-trade system is going to require a lot of careful tracking, especially when you throw in some extra wrinkles like the emission allowances that Congress is prepared to give away for free to many of the biggest polluters. How to price those allowances and whether there should be tax implications for them has already been the subject of a hearing in the Senate Finance Committee (see Senate Considers Cap-and-Trade Taxes).
Accountants in Europe have been doing some of this work for the past several years, as Europe is somewhat ahead of the U.S. in efforts to control greenhouse gas emissions. But there will still be plenty of work for U.S. accountants to do in this area. After all, we never did get that whole British thermal unit thing going over here.