Biodiesel vs. petroleum: greenhouse gas emissions and N2O

A press release recently reported research that claims biodiesel will cause more greenhouse gas effect than using petroleum oil. The gist is that agriculture with industrial fertilizers release some N₂O unintentionally as part of nitrogen fertilization, and that nitrous oxide has a much stronger effect on global warming because it has a long lifetime in the atmosphere. The UN defines a "Global Warming Potential" for each greenhouse gas. Lifetime in the atmosphere is the primary factor (perhaps the only factor?), so nonreactive gases like CFCs, which live nearly forever, have incredible numbers (50000) for their "effect". CO₂, though, is just defined as 1, even though it has a variable lifetime in the atmosphere of 5-200 years (page 38). I don't know if the spectral absorption of each gas was taken into effect for these--I see no information that it is. N₂O lives for about 120 years in the atmosphere, a fairly nonreactive gas, and it is this multiplication factor, (296x), that drives the conclusion about how biodiesel via rapeseed is worse than petroleum in greenhouse gas emissions.

I would have liked to read the actual paper via my institutional subscription, but it's not available yet online or in paper.

The linked press release is actually from a tropical conservation group, and interestingly they happened to add a graph with yields of biodiesel per acre, showing rapeseed as middle of the pack in terms of yield. What would happen to the analysis with other crops? What if we didn't use so much nitrogen fertilizer or didn't exclusively produce rapeseed? (You can nitrogenate with legumes to avoid using some fertilizer). Was the absorption of CO₂ from the atmosphere into the plant matter taken into consideration during the analysis? Questions I have, answers I can't find.

You might know rapeseed by another name: a special variety breed called canola (CANadian Oil Low Acid), which has much lower amounts of a naturally occurring toxic acid in it.

National Energy Policy

Sam, Colin and I were talking about biodiesel last night as walk-home talk fodder. It's a great thing--a no-modification substitute for fossil fuel diesel. Every gallon of biodiesel does nothing for carbon or pollution emissions or energy use, but reduces our dependance on Middle-East oil by a gallon. Naysayers complain about its sluggishness in cold weather, but this is standard behavior for #2 diesel, and complaints from Minnesota about it are related to poor-quality vendor biodiesel. Get companies that care about (or are forced to) producing a quality product and the clogs will stop.

The New York Times is reporting that President Bush will be talking about national energy policy in tonight's State of the Union. As usual, instead of dealing with proven strategies for increasing efficiency, he will argue for more pie-in-the-sky ideas that are far off. Far off enough to dump large subsidies into corporations for research of bad ideas, like the hydrogen car. Remember the hydrogen car? Instead of increasing today's automobiles' gas mileage by a few MPG by raising the CAFE requirements and getting the huge exemption of SUVs into the fold, he dropped them and asked for research into a non-proven, non-existent technology. Drop the idea of fuel-cells for cars. Stick them in houses, where they would actually work great.

It's a standard technique--drop funding for some project that could work but isn't on their party's agenda (cough hybrids cough). Claim that you have to use that money to research for something in the future like the hydrogen car. Watch as corporations use that R&D money to do nothing important. Quietly drop funding a few years later, claiming hydrogen cars weren't feasible. Congratulations! You've killed funding for the thing the other party wanted, without people noticing. Sound familiar, NASA? Drop science funding for "Manned space exploration of the Moon". Quietly kill that in a few years. Science funding never comes back.


The government should do three things for the energy security of the United States.
1. Spend on Research and Development, and avoid throwing money at corporate welfare. Science is very important for the long-term future, and its funding should never be in jeopardy.
2. There is nothing inherently wrong in nuclear power--it's cleaner than coal (yes, a point for another post). We need new energy sources as use naturally increases with time, and it's the most efficient way.
3. Reprocess nuclear fuel and recover the huge amounts of wasted U-235 and Plutonium that are just left to rot. Reprocessing would drop the need to immediately build Yucca Mountains every twenty years.
4. Encourage inexpensive solar energy development. Why haven't we powered Las Vegas, Los Angeles, San Diego, or Phoenix via solar power yet? Just using simple solar water heaters is a cheap and great start. My family heated our water for years with solar--why can't everyone in the southwest do this?
5. Biodiesel is a great option to immediately encourage--a direct replacement for diesel, especially in warm climates. Subtracting the national cost of supporting Middle-East oil, it becomes cheaper than you think.
6. Increase the efficiency of cars, and continue tax credits for all hybrids, including popular ones, but don't let the manufacturers trade efficiency for power.