Illustration, ‘Meat and Methane’, by Mike Licht, NotionsCapital.com.
A recent news feature in Nature Climate Change, Light is cast on a long shadow, notes the warming relations (forgive the pun) between scientists in the livestock and climate change communities.
‘The fields of climate change and livestock research have not always been cosy bedfellows. But they are ironing out their difficulties and looking ahead.
‘Six years ago, the United Nations Food and Agriculture Organization (FAO) published a report saying that livestock release more greenhouse gases into the atmosphere than transport. Or, put more precisely, livestock contribute 18% of the planet’s greenhouse-gas emissions. This is mainly because carbon dioxide is released when forests are chopped down to create space to grow feed, because poorly managed slurry and manure release lots of nitrous oxide, and because ruminants emit copious methane as flatulence.
‘The livestock research community did not appreciate the storm of media attention that this whipped up. Many researchers also disputed how the FAO had done its sums. . . .
‘However, agricultural sectors such as the dairy industry are closely involved in benchmarking for the latest assessments of greenhouse-gas emissions. An organization called the Global Research Alliance on Agricultural Greenhouse Gases was set up in late 2009 and now comprises 30 countries. Such steps seem to have drawn the estimates closer together. “The numbers are now not fundamentally different to what was in that 2006 report,” adds [FAO's Irene] Hoffmann.
Mario Herrero, a researcher at the International Livestock Research Institute (ILRI), considers the range of results from respectable studies to lie between about 10 and 18%—putting the FAO’s original figure as his upper bracket.
‘Researchers are now at least as interested in how climate change will alter where different species and breeds of livestock will flourish around the world—and how human livelihoods will be affected. Livestock are an important source of income for the poorest one billion people on the planet. Currently the sector contributes between 30 and 40% of the gross domestic product of many sub-Saharan African and South Asian countries.
It’s not a sector you can dismiss and decide that we shouldn’t all be eating meat. It’s not as simple as that,” says Herrero.
‘Livestock will become more important in coming decades. As the middle classes of developing countries swell, they are buying more meat and dairy products per capita; they are on course to demand twice the current amount of livestock products in 2050.
‘There are plenty of simple ways to improve the amount of meat or milk produced for each unit of emissions. . . .
‘The greatest efficiency gains can be made in the developing world. . . . Herrero and his ILRI colleague, Philip Thornton, have calculated how much methane and carbon dioxide release could be avoided in the typical animal husbandry systems found in tropical rangelands . . . . [I]f the advice of experts were adopted at the kind of rates that have been historically common, 4% of the global agricultural mitigation potential to 2030 would be achieved.
You could use really simple ways to produce twice the amount of milk per greenhouse-gas unit,” says Herrero, “but, of course, you need farmers to have better access to markets and so on. Without the right incentives, sustainable intensification won’t happen.”
‘Herrero foresees the potential to pay livestock farmers in tropical rangelands for maintaining their herds at the right densities and moving them around in an appropriate way. . . .
‘Genomics should benefit the livestock sector more broadly. . . . Knowing which genomic features give a cow a milk-producing advantage in the heat can help farmers selectively breed better herds. . . .
Particularly diverse breeds tend to occur in Africa, says Olivier Hanotte, of the University of Nottingham. . . . Moreover, because these breeds are rare, they are rapidly being lost as their owners seek to hybridize them with more productive, internationally common breeds.
‘This invisible loss worries many in the field. Genes for characteristics that may prove useful—even essential—in the future could disappear. One way to avoid this is to keep genetic resources in biobanks. . . . Potentially losing breeds that confer resistance to pathogens is troubling. And that is where African breeds can be particularly helpful. But the world needs to collect data on this before it is too late. . . .
Livestock research has much to contribute to mitigating and adapting to climate change. Surely, the first step is to give it more than 3% of agricultural research money.’
Subscribers can read the whole article by Anna Petherick in Nature Climate Change Vol. 2, pages 705–706: Light is cast on a long shadow, 27 Sep 2012: doi:10.1038/nclimate1703