by nanne
Sat Dec 22nd, 2007 at 06:10:46 PM EST
Peter Sain ley Berry is out to get my goat with his latest column in the EUobserver:
Making cars more efficient will not necessarily curb our emissions
Just the title is false. Making cars more efficient will curb our emissions. Not as a matter of logical necessity, but as a matter of empirical fact.
Sain ley Berry gets out the usual argument made in this context, known among economists as Jevons paradox and among greens as the rebound effect.
Moreover, the reason that vehicle emissions are increasing is not, surely, that people are buying bigger cars, but that they are buying more cars and driving them further. This may be because, relative to everything else, fuel prices have fallen in Europe since the 1950s, and the capital cost of vehicles has tumbled.
Improving car emission performance will reduce motoring costs even further. We may emit less carbon per kilometre, but overall there will be more cars and more kilometres. It does not necessarily follow that if emissions per kilometre fall, then total emissions will fall. This is particularly true if a big car is substituted by two smaller cars.
(crossposted)
There is an extensive body of research on the increase of use that happens as a result of efficiency increases, especially with regard to Europe and the US. For driving cars the rebound effect is 10%, possibly lower, at the low end, and 30% at the high end. This means that 1 unit of energy efficiency increase will result in 0.9 to 0.7 units of reduction of consumption.
The opposing argument made by Sain ley Berry, that the only thing that will work is an increase in the cost of fuel, is exactly wrong. Driving (not the same as fuel consumption) is highly price-inelastic. An increase in fuel prices will mainly be useful to get people to change to fuel-efficient cars, not to get them to drive less. Unless you start talking about price increases of 100% and above. Now, I would like those. I would also like a pony.
In general, Peter Sain ley Berry discusses the measure to set mandatory CO2 limits for cars on its own merits (and gets most things wrong right there). The measure, however, is not taken in isolation. It is part of a comprehensive strategy to reduce carbon emissions and to increase resource efficiency throughout the European Union. It relates to a large set of different EU policies (for instance on emission levels for other forms of pollution), national policies (fuel taxes, road taxes) and local policies (congestion charges, or even simple parking fees) that directly regulate cars. The measure would still make sense in isolation. It makes even more sense in the actual context.
One of the most interesting results of the mandatory CO2 limits will be the technological changes they will spur. It is very difficult for high-end manufacturers to meet the limits without shifting to hybrid vehicles (reduced performance is a bad sell, I reckon). Hybrids can be a stepping stone towards all-electric vehicles (or fuel cell/electric hybrids for all I care) and thereby contribute to a carbon-neutral future.
Rebound effect and cars reading:
De Haan, P.; Mueller, M.G.; Peters, A. (2006): Does the hybrid Toyota Prius lead to rebound effects? Analysis of size and number of cars previously owned by Swiss Prius buyers. Ecological Economics 58 (3), pp. 592-605.
Grotton, F. (2001): Energy Efficiency and the Rebound Effect: Does Increasing Efficiency Decrease Demand?. CRS Report for Congress, National Library for the Environment (link).
Schipper, L. and M. Grubb (2000): On the rebound? Feedback between energy intensities and energy uses in IEA countries. Energy Policy 28 (6-7), pp. 367-388.
