Where CO2 comes from

This post will deal with US emissions for 2006. Again, things can be divided into three major parts. Electrical generation accounts for 40% of all US CO2 production. Transport accounts for at least 33% of CO2. Everything else emits the remaining 27%.


Electrical Generation

This sector is the leading emitter of CO2. Furthermore, CO2 emissions from this sector are dominated by coal burning power plants. Coal plants alone account for 33% of all US CO2 production. Mostly, they run base load.

Replacing these coal plants with something else is, in my view, the easiest way to battle global warming. Nuclear power would be an ideal replacement for this coal. This one simple move could cut US CO2 production by one third without anything else having to be done. France already gets all its base load from nukes. Unlike wind or solar, nukes have a proven capability to generate massive quantities of power dependably and at an economical price.

The remaining emissions from this sector come from natural gas. Much of this is used to produce peaking power. Because of high capital costs, nuclear power is not a suitable replacement. Hydroelectric works very well, but is limited by availability of sites. Wind and solar can make a contribution here, if costs are competitive and if ways can be found to manage their fluctuating output.


Transport

Emissions from this sector come entirely from burning oil, mostly in the form of gasoline, diesel and jet fuel. It accounts for 33% of US CO2 production. I believe there is a strong case for including emissions from oil production and refining, which are usually counted under industrial, as transportation. These account for 5% of America's total emissions and bring transportation's share up to 38% of total emissions.

Cutting emissions from this sector is problematic. There are no easy substitutes for oil. Natural gas is a proven alternative, although it adds a few thousand dollars in cost to a car. There are natural gas burning buses on the road and Honda sells a natural gas powered Civic. Natural gas cuts CO2 emissions by 25% on an energy equivalent basis. Unfortunately Natural gas is not abundant and the biggest reserves are in the Middle East and Russia.

Biofuels work best for tropical countries. Brazil's sugar cane ethanol program seems to work well. America's corn to ethanol program requires lots of natural gas for ethanol production and is best analysed as a way to turn natural gas into a liquid fuel. There is little, if any, energy gain over burning the natural gas directly.

The best strategy here is conservation. European cars use much less than their US equivalents because they are smaller and diesel engines are much more common. The new CAFE standards approved by Congress should reduce the consumption of the average American car by 29% by 2020.

I believe that a great deal of the CO2 reductions in transportation will be driven by Peak Oil rather than by concerns over global warming.


Everything else

This accounts for 22% of US emissions if oil refining is excluded. Industrial emissions account for 12%, residential for 6% and commercial for 4%. This excludes the CO2 emitted to produce electricity which is used by these sectors. Industrial emissions would be higher if we didn't import many goods from overseas. Industrial emitters can often relocate overseas to escape heavy handed US global warming rules.