Growing and burning many biofuels may actually raise rather than lower greenhouse gas emissions, a new study led by Nobel prize-winning chemist Paul Crutzen has shown.1 The findings come in the wake of a recent OECD report, which warned nations not to rush headlong into growing energy crops because they cause food shortages and damage biodiversity.
Crutzen and colleagues have calculated that growing some of the most commonly used biofuel crops releases around twice the amount of the potent greenhouse gas nitrous oxide (N2O) than previously thought - wiping out any benefits from not using fossil fuels and, worse, probably contributing to global warming. The work appears in Atmospheric Chemistry and Physics and is currently subject to open review.
'The significance of it is that the supposed benefits of biofuel are even more disputable than had been thought hitherto,' Keith Smith, a co-author on the paper from the University of Edinburgh, told Chemistry World. 'What we are saying is that [growing many biofuels] is probably of no benefit and in fact is actually making the climate issue worse.'
Biodiesel and corn ethanol both suffer from the same problem. Good, two stupid government programs to kill off.
Crutzen, famous for his work on nitrogen oxides and the ozone layer, declined to comment before the paper is officially published. But the paper suggests that microbes convert much more of the nitrogen in fertiliser to N2O than previously thought - 3 to 5 per cent or twice the widely accepted figure of 2 per cent used by the International Panel on Climate Change (IPCC).
For rapeseed biodiesel, which accounts for about 80 per cent of the biofuel production in Europe, the relative warming due to N2O emissions is estimated at 1 to 1.7 times larger than the quasi-cooling effect due to saved fossil CO2 emissions. For corn bioethanol, dominant in the US, the figure is 0.9 to 1.5. Only cane sugar bioethanol - with a relative warming of 0.5 to 0.9 - looks like a viable alternative to conventional fuels.
Some previous estimates had suggested that biofuels could cut greenhouse gas emissions by up to 40 per cent.2
So unfortunately bioethanol advocates in Europe can still rationalize incentives that encourage Brazilians to tear down rain forests to plant more sugar cane for ethanol.
When the extra N2O emission from biofuel production is calculated in "CO2-equivalent" global warming terms, and compared with the quasi-cooling effect of "saving" emissions of fossil fuel derived CO2, the outcome is that the production of commonly used biofuels, such as biodiesel from rapeseed and bioethanol from corn (maize), can contribute as much or more to global warming by N2O emissions than cooling by fossil fuel savings. Crops with less N demand, such as grasses and woody coppice species have more favourable climate impacts. This analysis only considers the conversion of biomass to biofuel. It does not take into account the use of fossil fuel on the farms and for fertilizer and pesticide production, but it also neglects the production of useful co-products. Both factors partially compensate each other. This needs to be analyzed in a full life cycle assessment.
Biomass energy is not the answer. Biomass energy is probably not even part of the answer. We need to move to a more electrified economy. The billions of dollars of US taxpayer subsidies for corn ethanol would be better spent on moving to nuclear, wind, and solar power.
The federal government heavily subsidizes corn growers and ethanol producers. Rolling Stone reporter Jeff Goodell observed in the July 24 issue that ethanol receives more than 200 tax breaks and at least $5.5 billion in subsidies per year.
According to Goodell, ethanol production represents only 3.5 percent of the nation's gasoline consumption, but it consumes 20 percent of the entire U.S. corn crop. The Energy Information Administration reported that "Ethanol relies heavily on Federal and State subsidies to remain economically viable as a gasoline blending component."
Congress is about to decide whether to give fast-growing biofuels a new supercharger by requiring that the nation use 36 billion gallons yearly by 2022 — 15 billion gallons from corn.
That is six times what is used today. Next in the schedule: The Senate and the House appoint members to decide whether the Senate-passed, 36 billion-gallon mandate survives.
If extended through 2022, as the Senate bill provides, the ethanol subsidies will cost taxpayers an estimated $131 billion, according to the Tax Foundation. Subsidies under the Lugar-Harkin measure would cost as much as $205 billion over the next 15 years.
$205 billion is a lot of money to waste.
The European Union has announced that it wants to replace 10 percent of its transport fuel with biofuels by 2020. China is aiming for a 15 percent share. The United States is already on track to exceed Congress' 2005 goal of doubling the amount of ethanol used in motor fuels to 7.5 billion gallons by 2012. In his State of the Union speech in January, President George W. Bush set a new goal of 35 billion gallons of biofuels by 2017. In June, the Senate raised it to 36 billion gallons by 2022. Of that, Congress said that 15 billion gallons should come from corn and 21 billion from advanced biofuels that are nowhere near commercial production.
Just because lots of governments decide some path is a good idea doesn't mean they all aren't being stupid.
|Share |||Randall Parker, 2007 September 22 10:43 PM Energy Biomass|