Exposing ‘Cowspirarcy’: a documentary that transforms cows into ‘Escape cows’ (1)

Recently I have watched a highly controversial documentary called 'Cowspiracy' in which it labels animal agriculture as the leading cause of ALL environmental problems e.g. deforestation, GHG emissions, biodiversity loss. Throughout the video, it consistently refers to the figure that animal agriculture contributes to 51% of global GHG emission. The narrator and co-producer Kip Andersen at the start of the documentary expresses deep concerns of limited impact an individuals can make to help the environment. Rather than challenging the failed politics of individual lifestyle change, he accuses the governments and environmental NGOs of hiding the 'truth' and not addressing the issue due to alleged financial linkages between them and the animal and dairy industries. It offers 'becoming vegan' as the ultimate solution to climate change. 

In the next series of posts, I will critically analyse the validity of its claims. Today, I will focus on the most astonishing claim in the film - 51% of the GHGs are created by livestock based on figures provided in a Worldwatch Institute report written by Goodland and Anhang in 2009.

Before unpacking this figure, let’s look at how the Cowspiracists have responded to criticisms on their official website. They stated:

‘The Goodland/Anhang analysis was peer-reviewed. In order for employees of the World Bank to do any press or have articles published they must have it cleared by the World Bank first. Goodland and Anhang used the global standard for measuring GHGs http://www.ghgprotocol.org/city-accounting, something that the FAO report did not even do.’

Firstly, just to be clear, the report was non-peer reviewed (Herrero et al2011) and in the documentary it simply brushes off the issue by stating ‘two advisors from the World Bank’ wrote this report. Secondly, the approach that Goodland and Anhang used has been regarded as oversimplifying the carbon cycle of animal agriculture and fundamentally flawed with insufficient information on its methodologies and evidences.  From the information available in Goodland and Anhang (2009), Herrero et al (2011) have usefully outlined and examined the difference in the approaches used to examine the impact of livestock farming on GHGs emission.

Difference 1: inclusion of carbon produced by livestock respiration

Goodland and Anhang (2009) included the carbon emitted by livestock respiration. This approach is not adopted by the Intergovernmental Panel on Climate Change (IPCC) inventory guidelines (IPCC, 2006) because the amount of carbon in the feed consumed by livestock is considered roughly the same as those carbon sequestered from photosynthesis. Therefore, if the carbon respired by cows are included, the amount of carbon sequestered during photosynthesis should also be taken into account.

In addition, researches have shown that grassland could be a significant carbon sink, given appropriate management is in place. For example, Liebig et al (2010) suggests that the grassland in the northern Great Plains (NGP) of North America are all carbon sinks for soil organic carbon, with sequestering rates ranging from 0.39 to 0.46 Mg C ha−1 yr−1 under different grazing management systems. There are other factors to contribute to global warming potential as well: CO2 emissions associated with N fertilizer production and application and CH4 released from enteric fermentation. The results show that heavily grazed pasture (HGP) and moderately grazed pasture (MGP) were found to serve as net CO2equiv. sinks, while heavily grazed crested wheatgrass pasture (CWP) was a net CO2equiv. source. This shows that under approximate management practice, more carbon could be locked up and help compensate for the GHG emission of animal farming.

Difference 2: use of a consequential approach in calculating emission resulted from land use and land use change

They calculated the foregone carbon loss had the forest not been converted and attribute this to livestock farming. However, the same practice was not done for land use change such as urbanisation and cropland. As a result, the proportion of livestock farming was raised significantly in comparison to other sources.

Difference 3: methane’s warming potential threefold higher than consensus

Goodland and Anhang (2009) proposes the 20yr global warming potential (GWP) of CH4 to be 72. Although the actual GWP is still debated in the scientific community (Shindell et al 2009), the values range from 23 to 25 for a time scale of 100 years. The time scale matters for the GWP because CH4 and its warming potential only lasts for around 12 years and diminishes afterwards. With a shorter time period, the GWP increases. What should be noted is that GWP is used to prioritise mitigation for a time scale of 100 years, although the appropriateness of this timeframe is also under debate. This becomes a political issue of how long we think mitigation should be. The catch with using a 20-year time frame is that they did not apply the same tripling effect on methane produced by other anthropogenic sources e.g. mining, natural gas production, reservoir construction and so on. Consequently, the significance of livestock GHG emission increases in comparison to other sources.

   

From the 3 methodological differences we may see why Goodland and Anhang (2009) have arrived at such an erroneous figure. What do other peer-reviewed scientific journal say then? According to FAO (2006), livestock alone accounts for 18% of GMG emission. The figure is revised down to 14.5% in 2013 (FAO, 2013). IPCC’s estimates of agriculture’s direct impact on GHG emissions range from 10-12%, however, this figure does not take into account of the use of fossil fuel in transport, fertiliser production and land use change (Smith et al 2007). According to Bellaby et al (2008), the figure increases up to 30% when the aforementioned processes are included. In Garnettet al (2011), its review reveals that food consumption contributes from 15% to 28% of overall national emission in developed nations. In the report published by United Nations, the agricultural sector takes up 10.32% of overall GHG emissions, of which 31.4% is caused by enteric fermentation. So overall the percentages vary, however, none have reached more than half of global GHG emission.

Therefore with all the evidence above, it is safe to say the 51% figure is an exaggeration. However, they also suggest that agricultural sector is still a key driver of GHG emission and should not be ignored.