Bioenergy’s free ride in Kyoto and national climate legislation is a recipe for disaster.

Bottom Line for Climate: Reduce CO2 (Even If Produced by Bioenergy)

Taking a little liberty with a Gertrude Stein poem, carbon dioxide (aka CO2) is carbon dioxide is carbon dioxide. CO2 is a greenhouse gas regardless of where it comes from and if you put additional CO2 in the atmosphere, you increase global warming regardless of where the CO2 comes from.

The purpose of any climate policy (or law or treaty) is to limit the amount of additional CO2 that goes into the atmosphere. In the case of fossil fuel burning that’s a no-brainer — all CO2 from fossil fuels is additional and should be treated as such.

But when it comes to bioenergy — energy derived from plant material or biomass — the situation becomes a little more complicated. In theory bioenergy is carbon neutral. The carbon in biomass was derived from atmospheric carbon dioxide during photosynthesis, and so the carbon dioxide put into the atmosphere by burning the biomass is not additional.

Because of this, Kyoto, Waxman-Markey, and other climate pacts and regulations have given bioenergy a free pass: they place no limit on the CO2 produced from bioenergy. Carbon emissions are not counted from growing or harvesting biomass for energy, nor are they counted when biomass is combusted for energy.

Not Fixing This Could Spell Disaster for the World's Forests

The problem is that the theoretical carbon neutrality of bioenergy is rarely achieved in practice. In fact, after accounting for the carbon released from land use changes (such as a farmer cutting down a forest to grow bioenergy crops like corn for fuel), many sources of bioenergy can have very high carbon emissions.

Failure to account for this fact in climate policy sets up a perverse system of incentives for cutting down forests and replacing them with bioenergy farms. (See here and here.) Such a system could ultimately lead to the destruction of much of the world’s forests, actually adding to instead of subtracting from the greenhouse gas loading of the atmosphere — not exactly the result climate policy makers have in mind.

A policy forum paper out today in Science by Tim Searchinger of Princeton University and colleagues (myself included) discusses how this omission came to be, the havoc it can wreak on the world’s forests and atmospheric greenhouse gas emissions, and how it can be remedied. Want to know more about this? Read the paper here.