Roger Pielke Jr. summarizes the key points from his work on climate and energy policies that work. Hint, Kyoto is not one of these policies.
By now there is really no excuse for any professional involved in climate policy not to understand the implications of the Kaya Identity. The risks of not understanding the Kaya Identity is that one can get caught out proposing magic as the main mechanism of reducing carbon dioxide emissions.
Developed by Yoichi Kaya, a Japanese scientist, in the 1980s as means of generating emissions projections for use in climate models, the identity is also an extremely powerful tool of policy analysis, because it encompasses all of the tools in the policy toolbox that might be used to reduce emissions. The identity is comprised of four parts:
- Per capita wealth
- Energy intensity of the economy (energy consumption/GDP)
- Carbon intensity of energy (carbon dioxide emissions/energy consumption)
If we wish to reduce emissions of carbon dioxide with the goal of stabilizing its concentrations in the atmosphere, then we only have four levers, represented by each of the factors in the Kaya Identity.
In The Climate Fix, I simplify even further by combining population and per capita wealth, the result of which is simply GDP, and by combining energy intensity and carbon intensity, the product of which is carbon intensity of GDP.
That means that there are only two ways to reduce emissions to a level consistent with stabilization of concentrations at a low level (pick your favorite number, 350, 450, 550 ppm — the policy implications are identical). One is to reduce GDP. The second is to reduce the carbon intensity of GDP — to decarbonize. While there are a few brave/foolish souls who advocate a willful imposition of poverty as the remedy to accumulating carbon dioxide, that platform has not gathered much political steam. (See discussion of the Iron Law in TCF).
Instead, the only option left is innovation in how we produce and consume energy. That is it — innovation is the only game in town. Consequently, the correct metric of progress in innovation is a decrease in the ratio of carbon to GDP. For those who wish to stabilize carbon dioxide emissions, the proper policy debate is thus how do we stimulate energy innovation?
Pricing carbon (or energy) is not a point of dispute.