In the fight against climate change, there are certain guiding principles that are beyond dispute: the need to abandon the extraction and use of fossil fuels is undeniable, even if the path forward is not a simple one and faces powerful opposing interests. However, other issues are always accompanied by heated debate that never seems to die down: for example, the production and consumption of meat versus plant-based foods. At this stage, it is hard to deny that the carbon footprint of raising livestock is considerable. But amidst the salad of facts and figures that are frequently tossed around—often contradicting one another—the ideological currents that take advantage of the debate to promote their positions, and the sometimes biased or incomplete arguments, the notion of whether or not to eat meat has become one of the most savoury—and oft-times bitter—debates surrounding the climate emergency.
Although the ecological impact of livestock farming is by no means a recent concern, it was in 2006 that a report by the Food and Agriculture Organization of the United Nations (FAO) entitled Livestock’s Long Shadow took the world by storm with a very concrete and powerful message and data point: livestock was responsible for 18% of global greenhouse gas (GHG) emissions, a higher share than global transport.
Pollution of livestock, a long fight for the numbers
But while the public and the media responded with either cheers or jeers, depending on their inclinations, other experts reacted with astonishment, as the figures did not tally with their own. In the end, the authors of the FAO report had to admit that their estimate was flawed: emissions from livestock covered the entire life cycle, while for transport they used the figure from the Intergovernmental Panel on Climate Change (IPCC), which only included direct emissions from burning fossil fuels.
As a result, the FAO’s own rectified data are less unfavourable for livestock: direct emissions amount to 5%, compared to 14% for transport, while for the life-cycle figure for livestock—lowered to 14.5%—there was no corresponding estimate for transport with which to compare it, although a higher figure was assumed. However, the FAO’s misrepresentations created a confusion that persists today, and which some activist organisations take advantage of to continue to spread the original misleading figure of 18%.
Broadly speaking, other national or regional agencies offer estimates in the same ballpark as those from the FAO. In the US, the Environmental Protection Agency (EPA) assigns 10% of emissions to the entire agriculture sector (crops and livestock), of which a quarter is accounted for by enteric fermentation—the expulsion of methane by ruminants such as cattle—and 12% by manure management. According to FAO global figures, these two sources account for just over half of livestock emissions, plus another 40% from the production of livestock feed. For its part, the European Union also estimates the GHG share of the agriculture sector at 10%, of which around 85% is accounted for by livestock, including the production of feed material.
This short review already reveals how, among livestock emissions data, the choice of figures, how they are presented and what they are compared to can be a powerful tool in shaping public opinion. Based partly on FAO estimates, a Greenpeace report in September 2020 put the share of livestock emissions in the EU at between 12% and 17%. The environmental organisation included contributions that other estimates separate into distinct categories, such as deforestation and land-use change, to convey the message that European livestock emit more GHGs than all the cars and vans in the EU.
Clarifications for a fierce controversy
This, in turn, drew criticism from experts such as Frank Mitloehner, an air quality and animal scientist at the University of California who has distinguished himself as one of the strongest advocates for livestock in the climate debate. Mitloehner pointed out how Greenpeace had perpetuated the FAO confusion by comparing the life cycle of livestock with direct emissions from transport. But Mitloehner’s detractors have accused him of a conflict of interest in receiving funding from the livestock industry.
But regardless of the discrepancies in the figures, the consensus can be expressed in the terms defined by the FAO in its Global Livestock Environmental Assessment Model (GLEAM): “The livestock sector is a significant contributor to global human-induced GHG emissions.” However, beyond that, there are nuances, as not all animal species and farming practices contribute in the same way: around 70% of global emissions due to enteric fermentation and manure are due to cattle, whether for meat or milk production, while the contribution is much lower for pigs (7%), sheep (4.5%), goats (4%) or poultry (1.5%).
This is why calls to reduce meat consumption for climate reasons have focused mainly on beef, a fact that has been dubbed by the media as the war on the hamburger or the burger ban. But as the largest GHG contributor, beef is also the sector with the greatest opportunities for mitigation. According to the FAO, there are large differences in emissions between different producers, depending on agro-ecological conditions, farming practices and supply chains. GLEAM does not analyse the impact of a reduction in consumption, but estimates that if all farms were to adjust to the levels of the lowest emitters, this footprint could be reduced by 33% without reducing overall production.
Specifically, the FAO points to farm efficiency and animal husbandry and health as areas for improvement, including better feeding to reduce methane generation— which accounts for 44% of livestock emissions—along with energy saving, manure recycling and more effective management of grazing land to help harness its potential as a carbon sink. The FAO therefore urges the relevant agencies to encourage and support these changes in the sector, and calls for research to find new and more sustainable feeding solutions.
It is these opportunities that the livestock sector and some experts are using to suggest that it is not about eliminating meat and milk, but about producing them better, especially when there does not seem to be agreement on how much benefit can be gained from reducing livestock farming. For example, the recent report from Greenpeace claimed that a 50% cut in livestock farming would save a similar share of GHG emissions, but a US study estimated that eliminating all livestock farming would only reduce emissions by 2.6%, a conclusion that in turn elicited conflicting responses from other scientists.
The problem of erasing meat overnight
Indeed, it is difficult to find a dispassionate debate on livestock, especially when so many interests are involved; a recent New York University study accused certain meat and dairy companies of having “contributed to efforts to undermine climate-related policies,” just as the oil giants did before them. As in the Mitloehner case, other livestock advocacy initiatives have come under fire from certain organisations for relying on scientists whose work deals with animal feed. But can it be considered a conflict of interest for a scientist to provide substantiated arguments in support of their area of expertise?
Yet even the FAO’s own experts have taken care to stress that livestock is the essential livelihood and main source of protein for half of the nearly 800 million people living in extreme poverty, and that its elimination would increase food insecurity and malnutrition. According to a recent European Commission (EC) report on the future of livestock farming in Europe, “livestock, especially ruminants, can have a positive impact on biodiversity and soil carbon via the maintenance of permanent grassland and hedges and optimised use of manure.” The EC adds that not all livestock farming can be lumped together, and that in order to “avoid oversimplification in the debate on the livestock sector and its impact,” the focus should be on promoting sustainable livestock farming and animal welfare.
Ultimately, eating less meat by those with the desire to do so and with access to alternative food sources is certainly a personal choice that benefits the climate. Meanwhile, science and industry are moving towards another no less controversial goal: lab-grown meat, a solution for some and an aberration for others. But as is often the case in the environmental debate, the key to a united effort may lie rather in turning the energies sometimes lost in confrontation towards a more productive goal: enhancing pathways to sustainability.