Informed consumers globally would doubtlessly have asked themselves this question at some stage. Meat and dairy production invariably top the list of production systems when discussing environmental hotspots of agriculture. When dealing with sustainability and livestock, a discussion of whether we should eat meat or not, and if we do which type, is inescapable. I initially set out to address both these questions (should we be eating meat AND if so, which type?) in this blog, however given the scope and complexity of these two issues, I quickly realized this could fill volumes. I am therefore not going to answer these questions here, but rather set forth some of the issues and challenges in livestock production that I feel we should know about as a step towards informing your own decisions.
For some context, let’s briefly explore a few important global trends about meat and dairy production. Firstly, the production of meat globally almost doubled from 1980-2004. Notably, in this period, total meat production tripled in developing countries, whilst in developed countries production increased by only 22%1.
Secondly, with the global population expected to be more than nine billion by 2050, there will be a substantial increase in the production and consumption of meat globally, some estimates suggest an increase in demand for meat by 2050 of more than 70%.
Thirdly, there is an evident shift in demand and hence production of monogastric livestock – primarily pigs and poultry. Currently, pork is the most widely consumed meat in the world, whilst poultry production is the fastest growing meat sector.
These growth projections will in future require a substantial increase in land resources dedicated to livestock rearing (including feed production), coupled with considerable increases in efficiency of production. Globally, livestock production is an important contributor to food security and people’s livelihoods, particularly in developing countries. Given the large differences, globally, in livestock production systems and animal type, ranging from intensive high input systems to extensive subsistence systems, one should be cautious in generalizing about which sustainability challenges face the sector. However, I think given the magnitude of global livestock production, we should highlight some generic sustainability challenges facing the production side of the sector:
FEED PRODUCTION: Eisler et al. (2014) speculate that ‘the 1 billion tonnes of wheat, barley, oats, rye, maize (corn), sorghum and millet poured annually into livestock troughs could feed some 3.5 billion humans’. Whilst this number doesn’t account for the fact that livestock can consume food humans can’t, nor that the product is consumable meat, it does give an idea about the amount of feed that needs to be produced to feed livestock. Feed production, aside from diverting food from humans, uses land and resources and will therefore have environmental impacts, for example loss of biodiversity from land/forest clearing, GHG emissions and water pollution.
WATER USE and POLLUTION: Given the large numbers mentioned above, it is unsurprising that livestock production is an extremely large consumer of water. The livestock sector has a very large impact on water use and water quality, which in turn impacts aquatic ecosystems. The consumption of animal products contributes to more than one-quarter of the water footprint of humanity. Water for feed production is the major factor behind the water footprint of animal products.
AIR POLLUTION and GREENHOUSE GAS EMISSIONS: Animal production is a significant source of GHG emissions – exactly how much is a debated issue, although recent estimates of the contribution of animal production to anthropogenic GHG emissions globally of approximately 18%6. Livestock production is also a significant source of ammonia gas which can cause both air and environmental pollution. The main sources of gaseous emissions in the livestock production sector are from feed production and processing (45%), ruminant enteric fermentation (39%), whilst manure storage and processing represent 10%.
Given the large impact livestock production has on natural resources, there is an intricate and complex link between BIODIVERSITY LOSS and livestock production, for example through habitat loss or change and pollution. Finally, an overview of sustainability issues related to livestock would be incomplete without mention of ANIMAL WELFARE. Generalization is a challenge when taking a broad, global view on livestock production systems. Regardless, ensuring animal welfare is a central challenge in many livestock systems across the world, particularly in industrialized systems.
So which meat should we be buying? How do we navigate such a choice, given the extent of what is described above? It’s a challenge, but a good start is to ask yourself – do I know where this meat was produced? Do I have an idea how was it produced? How much of this type of meat should I really be eating? These aren’t always easy questions to get answers to, but increasingly critical consumers asking the right questions – and seeking answers to these questions – actually can make a difference.
 Steinfeld, H., Gerber, P., Wassenaar, T., Castel, V., Rosales, M., de Haan, C., 2007. Livestocks Long Shadow, FAO Rome.
 Alexandratos, N. & J. Bruinsma. 2012. World agriculture towards 2030/2050: the 2012 revision. ESA Working paper No. 12-03. Rome, FAO.
 Eisler, M.Cet al. 2014. Agriculture: Steps to sustainable livestock. Nature. 507, 32.
 Feed conversion ratio (ie efficiency) in livestock is however low.
 Mekonnen MM, Hoekstra AJ (2012) A global assessment of the water footprint of animal products. Ecosystems 15:401–415.
 Gerber, P., Steinfeld, H., Henderson, B., Mottet, A., Opio, C., Dijkman, J., Falcucci, A., Tempio, G. Tackling climate change through livestock – A global assessment of emissions and mitigation opportunities. 2013. Food and Agricultural Organization of the United Nations (FAO), Rome.