Why Earthmaker?

Worm farms not green?

2 Oct 2007

Worm farms produce laughing gas - but is this nitrous oxide a laughing matter?

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Worms not as ‘green’ as they seem, OU researcher finds

12 Jul 2007

Worm gas concerns

In these environmentally aware days, an Open University researcher has come up with some environmental news that has people listening. The reason for the attention is that it seems to clash with the green agenda because Jim Frederickson, a senior research fellow at The Open University's Faculty of Technology, found that worms may not be as environmentally friendly as many think.

Research shows that as worms munch through our kitchen scraps on the way to making compost for us, they give off nitrous oxide. It’s not as famous as carbon dioxide in environmental concerns, but it is 296 times more powerful than CO2.

Frederickson, says: "We know from research in Germany that a third of the nitrous oxide emissions coming from the soil are associated with worms.

"What we found from looking at large worm composting systems is that their emissions could be comparable in global warming potential to the methane from landfill sites.

"The amount of worm composting is very, very small and the amount of landfill is huge. But landfill sites are quite well run these days and it is possible to extract about half the gas they generate and use it for electricity generation.

The research done at The Open University by Jim Frederickson and his colleagues was on large commercial worm composting beds where worms can emit much of the nitrogen in waste as damaging gas.

As the Government wants to increase the amount of household waste that is composted and recycled to 40% in 2010 and is thinking about financial incentives for recycling and setting a new national target for the reduction of commercial and industrial waste going to landfill, it could mean more domestic and commercial worm composting.

Jim Frederickson suggests "The amount of nitrous oxide emitted by large scale worm composting is something we should be looking at before we go further down that route." In addition, we also need to investigate emissions from domestic-scale worm bins as there are tens of thousands of these being used.”