greenhouse gases, livestock and grass – not such a simple story

For those of you who follow us on twitter, you may have spotted my tweet last week on the statistics of Caroline Spelman the Environment Secretary’s speech to the influential Oxford Farming Conference.

Spelman mentioned food security four times, energy three times, waste once, the environment once and no mentions of nature nor biodiversity. She did mention natural three times though.

But the most intriguing of all was the 15 mentions of climate change. Agriculture has a big greenhouse gas footprint considering what a relatively small component of the economy it is. Defra is clearly determined to reduce that footprint. Measuring that footprint accurately is essential if the industry is going to reduce it.

And the intensive agriculture industry naturally wants to present itself as doing everything it can to reduce its greenhouse gas emissions – better still if it can take the moral high ground and claim that intensive agriculture is by definition more climate-friendly than extensive systems.

This is particularly true for the livestock sector, where methane emissions from ruminants form such a large component of the total GHG footprint. The intensive livestock sector, led by their trade body EBLEX is pointing the GHG finger at extensive livestock systems ie those where stock feed on “rough grazing” or wildlife habitats as they are also known, often in the uplands. EBLEX has developed a “roadmap to sustainability”, including the 2009 report change in the air in which they argue that more intensive livestock systems produce less greenhouse gas emissions because they are more efficient at converting forage into meat. This work is based on a GHG calculator called ECO2 which is supposed to take into account all the variables that go together to make up the complete GHG footprint for a livestock farm.

So I was surprised to hear, at a meeting of the Climate Change Committee I attended down here in Dorset before Christmas, that the “Carbon Calculators”  available for the agriculture industry to use, do not after all include all aspects of a system – especially the critical role of carbon sequestration in grassland soils.

One farmer who attended the meeting, Bill Grayson, presented a paper, which has now been published in the European Forum’s latest newsletter La Canada. He shows in this article that when the carbon storage in low intensity grasslands is taken into account, extensive systems have the lowest overall carbon footprint after all.

Not only that, but the efficient way that traditional breeds convert semi-natural forage, compared with modern breeds which are bred to grow on high nutrient diets, has not been taken into account at all.

EBLEX’s third roadmap to sustainability is due for publication any time now. This will provide an opportunity for us to revisit the claims from the intensive livestock sector that intensification is the only route to sustainability.

Also due for publication imminently is research carried out by CEH Lancaster into carbon sequestration in grassland soils under different management conditions. This looks like it will be very important research, which will help identify the best ways to manage grassland for carbon sequestration, alongside all the other ecosystem services it provides.

I’ll return to this topic once these two reports have been published.

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About grasslandstrust

The Grasslands Trust is the only national UK charity that focuses entirely on saving grasslands that are valuable because they are rich in wildlife, history, or for other reasons.
This entry was posted in carbon storage, Ecosystem services, farming, grasslands, semi-natural and tagged , , , , , . Bookmark the permalink.

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