So much for Thoma's comments and quotes of Sachs. As promised, here are direct links to the McKinsey study, the video, and the summary
Consensus is growing among scientists, policy makers, and business leaders that concerted action will be needed to address rising greenhouse gas (GHG) emissions in the United States. The discussion is now turning to the practical challenges of where and how emissions reductions can best be achieved, at what costs, and over what periods of time.
The central conclusion:
The United States could reduce GHG emissions in 2030 by 3.0 to 4.5 gigatons of CO2e using tested approaches and high-potential emerging technologies. These reductions would involve pursuing a wide array of abatement options with marginal costs less than $50 per ton, with the average net cost to the economy being far lower if the nation can capture sizable gains from energy efficiency. Achieving these reductions at the lowest cost to the economy, however, will require strong, coordinated, economy-wide action that begins in the near future.
Project methodology overview
Starting in early 2007, a research team from McKinsey worked with leading companies, industry experts, academics, and environmental NGOs to develop a detailed, consistent fact base estimating costs and potentials of different options to reduce or prevent GHG emissions within the U.S. through 2030. The team analyzed more than 250 options, encompassing efficiency gains, shifts to lower-carbon energy sources, and expanded carbon sinks.