Stabilizing Emissions with Policy Wedges

Robert Socolow and Stephen Pacala have a plan to keep carbon emissions in check (as discussed in today's Global Warming Debate). The plan is based on a divide-and-conquer strategy: divide the total emission reductions needed into manageable pieces ("wedges") and propose existing technologies to tackle each wedge.

Total carbon emissions are forecast to be 14 billion tons a year by 2056. To get back to the 2006 level of 7 billion tons per year you need seven billion-ton-a-year wedges for the next fifty years. Pacala and Sokolow actually propose 15 wedges covering end-user efficiency and conservation, power generation, carbon capture and storage (CCS), alternative energy sources and agriculture and forestry--an ample menu of existing technologies to choose from. And, after 2056, we can implement another 3 wedges to get us back to 4 billion tons a year which is around the amount of carbon that the existing earth systems can effectively absorb.

Essentially, Pacala and Sokolow take the Emission Equation and focus on carbon intensity, energy intensity and population growth (it could be one wedge if reduced) while leaving output per capita (economic growth) alone. This is a very attractive formulation (it's even been applied to controlling the US health care system). Electric cars, wind turbines, solar panels, new CCS coal-fired power plants, super-insulated homes, etc. all create economic growth and improve our standard of living.

There is even a Stabilization Wedge Game that can be used as a teaching tool. Actually, the game has drawn more criticism than the scientific articles: the costs are underestimated, the implementation time is underestimated and the demand side (population growth and economic growth) is ignored in favor of technological "fixes".

My problem with Stabilization Wedges is that they ignore the systemic aspects of the environment. Carbon is not the only problem facing the world system. Demand has increased our ecological footprint beyond sustainable levels and there is no quick technical fix for creating more ecological capacity than our current Earth system can provide. We will need both supply and demand solutions.