Biofuels could increase global warming with laughing gas, says Nobel prize-winning chemist

Sep 21, 2007

Growing and burning many biofuel crops may actually raise, rather than lower, greenhouse gas emissions. That’s the conclusion of a new study led by Nobel prize-winning chemist Paul Crutzen, best known for his work on the ozone layer.

He and his 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, also known as ‘laughing gas’) than previously thought – wiping out any benefits from not using fossil fuels and, worse, probably contributing to global warming.

‘The significance of it is that the supposed benefits of biofuels are even more disputable than had been thought hitherto,’ Keith Smith, a co-author on the paper and atmospheric scientist from the University of Edinburgh, told Chemistry World magazine. ‘What we are saying is that [growing many biofuels] is probably of no benefit and in fact is actually making the climate issue worse.’

The work is currently subject to open review in the journal Atmospheric Chemistry and Physics, and Crutzen himself has declined to comment until that process is completed. But the paper suggests that microbes convert much more of the nitrogen in fertilizer to nitrous oxide than previously thought – 3 to 5 per cent, which is twice the widely accepted figure of 2 per cent used by the International Panel on Climate Change (IPCC) to calculate the impact of fertilizers on climate change.

For rapeseed biodiesel, which accounts for about 80 per cent of the biofuel production in Europe, the relative warming due to nitrous oxide emissions is estimated at 1 to 1.7 times larger than the relative 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 better alternative to conventional fuels.

In the wake of the findings comes a recent report prepared by the OECD for a recent Round Table on Sustainable Development, which questioned the benefits of first generation biofuels and concluded that governments should scrap mandatory targets. Richard Doornbosch, the report’s author, says both the report and Crutzen’s work highlights the importance of establishing correct full life-cycle assessments for biofuels. ‘Without them, government policies can't distinguish between one biofuel and another – risking making problems worse,’ he said.

Read the full text of this Chemistry World exclusive at: www.rsc.org/chemistryworld/News/2007/September/21090701.asp

The full research paper is available here: www.atmos-chem-phys-discuss.net/7/11191/2007/acpd-7-11191-2007.html

Source: Royal Society of Chemistry

Explore further: Los Alamos radiation release could have been prevented (Update)

Related Stories

Recommended for you

China's struggle for water security

1 hour ago

Way back in 1999, before he became China's prime minister, Wen Jiabao warned that water scarcity posed one of the greatest threats to the "survival of the nation".

Canada revises upward CO2 emission data since 1990

1 hour ago

Canada revised its greenhouse gas emission data from 1990 to 2013 in a report Friday, showing it had higher carbon dioxide discharges each year, and a doubling of emissions from its oil sands.

Climate censorship gains steam in red states

15 hours ago

While plenty of people found humor in the recent news that officials in Florida and Wisconsin are censoring state workers' ability to talk about, much less work on, climate change, other states are not necessarily laughing. ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.