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Curbing emissions

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THE warning from the Intergovernmental Panel on Climate Change (IPCC) that global warming is ‘unequivocal’ and that limiting it will require ‘substantial and sustained reductions of greenhouse gas emissions’ attracted so much media attention last week that another report on the subject is in danger of being overlooked. The day before the IPCC announced its conclusions,1 the Food and Agriculture Organization (FAO) published a report looking specifically at the contribution of livestock production to greenhouse gas emissions and how this might be reduced. It has been known for some time that livestock production makes a significant contribution to global greenhouse gas emissions. The FAO's report tends to confirm this, estimating that emissions associated with livestock supply chains add up to 7.1 gigatonnes of carbon dioxide-equivalent a year – or 14.5 per cent of all human-caused emissions.2 The good news, however, if there is any good news to be had in this debate, is that this could be cut substantially, by up to 30 per cent, through wider use of existing best practices and technologies.

This is a useful contribution to a debate in which it is often suggested, not altogether helpfully, that the problem of livestock emissions could be solved simply by exhorting people to eat less meat. While this may be true to a certain extent, it rather neglects the fact that the world's population is expected to grow from 7 million to 9 million over the next 35 years or so and that demand for livestock products is increasing. It also tends to ignore the fact that, in many parts of the world, where other forms of food production may not be an option, people depend on livestock for their livelihoods.

To arrive at its estimates, the FAO looked at greenhouse gas emissions at different stages in various livestock supply chains, including the production and transport of animal feed, on-farm energy use, emissions from digestive processes and manure decay, as well as post-slaughter transport, refrigeration and packaging of products. It found that the main sources of emissions are feed production and processing (45 per cent of the total), outputs of digestion by cows (39 per cent) and manure decomposition (10 per cent). The rest was attributable to the processing and transportation of animal products. Its report suggests that, through wider adoption of best practices and technologies in feeding, health and husbandry, and manure management, as well as greater use of biogas generators and energy-saving devices, producers could help the global livestock sector significantly reduce its output of global warming gases. Noting that there is a strong link between resource use efficiency and the intensity of greenhouse gas emissions, it suggests that the potential for reducing emissions lies in enabling all producers to change to practices already being employed by the most efficient operators.

The report argues that substantial reductions in emissions can be achieved across all species, systems and regions, with the greatest potential for cuts being in low productivity ruminant livestock systems in South Asia, Latin America and Africa. However, it points out, in developed countries, where emission intensities are relatively low but the overall volume of production and therefore emissions is high, a small reduction in intensity could still result in significant gains. This, it says, is the case for dairy farming in Europe and North America, and for pig rearing in East Asia. Giving a breakdown of greenhouse gas emissions for the different species of livestock, it notes that raising cattle contributes 65 per cent of the livestock sector's total greenhouse gas emissions, but also offers the largest potential for reductions.

Given the scale and diversity of the global livestock sector, and variations from country to country, changing practices will, the FAO points out, require a broad mix of policies, incentives and work at ground level. The focus, it says, should be on knowledge transfer, financial incentives, regulations and raising awareness; it adds that better policies are needed to facilitate the transfer and use of efficient practices already adopted by a minority of producers, as well as to encourage the development of new solutions. It points out that efficient processes and technologies can also boost productivity and thus contribute to food security and poverty alleviation, and notes that, to ensure participation by developing countries, measures will need to target not just emissions mitigation goals but development objectives as well.

From the FAO's report, it would appear that possible interventions to reduce emissions from livestock are mainly based on technologies and practices that improve efficiencies at animal and herd levels, including better feeding practices, animal husbandry and health management. These are areas in which vets can contribute, both practically and in terms of research. There's something about climate change that seems to provoke strong opinions, but the scientists on the IPCC seem pretty clear that there is a problem. Whether to mitigate the effects of climate change, ensure future food supplies, help meet development goals, or simply for economic reasons, there's a lot to be said for improving production efficiency in all kinds of systems. It would seem to make sense to get cracking now.

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