Letter from Europe: Farming fights its image as climate wrecker number one

Thursday, June 10, 2010

From kangaroo vaccines to biogas production, agriculture is countering criticisms that it is a major greenhouse gas producer with a series of practical solutions

by NORMAN DUNN

Farming's carbon footprint has caught the public's attention in Europe with meat and milk producers finding it especially hard to win acceptance for new major projects.

The main reason is a rash of media "revelations" that have shifted the main responsibility for global warming and atmospheric pollution away from excessive use of hydrocarbons onto methane from belching cows and ammonia from swine.

In fact, the spotlight has been burning so brightly on the role farm animals play in climate change that it's hard to believe there's not been some serious media manipulation by other sectors.

Certainly, petroleum and automobile interests must have been relieved to read in a 2006 report from the United Nations Food and Agriculture Organization (FAO) that global livestock production is now responsible for sending seven billion tons of CO² equivalents per year into the atmosphere. And that this output totals something like 18 per cent of global greenhouse gas emissions.

This certainly isn't good news for farming's image. But let's take a closer look at these figures. The University of California-Davis's Dr. Frank Mitloehner pointed out during this spring's Animal Chemical Society (ACS) conference that all aspects of meat and milk production – fertilizer for forage, feed manufacture and transport, along with the processing of the livestock products – had been taken into account for these figures.

This overall approach, he claims, was not taken when calculating the emissions from transport. Here, the report used only CO² equivalent production from the burning of fuel.

This approach, said Mitloehner, was typical of populist research that dumps much of the required action onto farming but ignores the huge potential for carbon savings in other fields. Critics want meat and milk production to be reduced, but smarter animal management could be just as effective, argued Dr. Mitloehner. "Producing less meat and milk will only mean more hunger in poorer countries." Also largely ignored at the moment is the amount of work already being done by the farming sector in reducing climate-relevant emissions.

Britain's National Farmers Union reacted to the FAO report by pointing out that intensive research into feed and livestock management towards reducing methane production had already helped achieve a 17 per cent reduction from U.K. agriculture in the last 20 years.

In fact, global warming gases from farming in the U.K. now only account for around seven per cent of the country's total, according to the union. 

Looking all around the world, there's now hardly an agricultural research institution anywhere not looking at new ways to cut greenhouse gas production. An example: kangaroos eat lots of grass and, just like cattle and sheep, they need the help of cellulose-degrading organisms to digest the forage.

The big difference is that these animals do not burp up methane as a byproduct. Instead, much less harmful acetates are produced by the kangaroos' gutmicroorganisms. So now the Australians are looking at the possibility of vaccinating cattle and sheep with microbes from the kangaroo digestion systems.

Back in Europe, perhaps the most promising tool for reducing greenhouse gas emissions from livestock farming is seen as biogas production from properly managed manure. And, of course, the biogas produced offers an environmentally friendly replacement for finite petroleum fuel. At Lund University in Sweden researchers showed that producing a kilowatt hour of energy from biogas releases 95 per cent less methane, carbon dioxide and nitrous oxide than the same energy from petroleum.

This sort of performance is a major reason why the Dutch Cattle and Meat Marketing Board (PVE) is looking for a national low-cost emission control system which might mean a simple "mini" biogas fermenter processing all the manure on every livestock farm. At Sterksel swine experimental farm, the hog unit produces 5,000 tons of manure annually. Here, one of these mini fermenters produces enough electricity and heat via biogas-driven generators to make the whole farm carbon-neutral, according to the PVE's John Horrervorts. First commercial models are expected on Dutch farms this summer.

But what about cattle out in the fields? Until just a few years ago, it was thought that there was no controlling emissions from the manure that's dropped there. But now purpose-built wood chip pads where cattle can feed and rest overnight in winter are absorbing tons of CO2 equivalents – and proving much cheaper than building a barn.

The wood chip pad idea comprises an unroofed excavated area with a 20-30 centimetre layer of wood and bark chips. There's now a string of trial outdoor pads across Britain and first results indicate around 20 per cent of manure liquid is absorbed, with the remainder usually being drained off into sealed storage.

Ammonia emissions are also reduced by 25 per cent compared with in-barn slatted floor systems. Cattle on wood chip pads are also proving healthier than barn-housed herds. And there's the great benefit of much less soil damage to the surrounding pastures.

Now Irish farmers are trying out the wood chip pad idea for their dairy herds in winter, yet another sign that every alternative offering cutbacks in greenhouse gases is being looked at now. BF

Norman Dunn writes about European agriculture from Germany.