Practice what you preach!

So far I have made quite a few blog posts on how dietary choice affects your carbon emissions. It’s all nice and good to talk about it, but no difference will be made unless action is taken! Therefore I took it upon myself since the beginning of the blog to become a part time vegetarian! Alongside cutting down my meat consumption, I also discovered a few other ways to cut down my personal carbon emissions.

I discovered this website where you can make pledges to save carbon emissions by changing little things in your daily life. Most actions are fairly achievable!

According to the calculation of the website, I will be able to save 200kg of CO2 over the next 2 month. This is achievable by doing the following:

• Having 3 vegetarian meals a week (24kg)
• Reduce food waste by finishing all the food cooked or bought (22kg)
• Only boil the right amount of water needed (2kg)
• Only eating sustainably sourced fish (7kg)
• Reducing the thermostats down by 3C (114kg)
• Putting my laptop on battery saving mode and turning it off when not used (7kg)
• Doing all my recycling correctly (21kg)
• Washing my clothes at 30C (2kg)
• Turning lights off when not used (1kg)

Assuming that average UK residents emit 9.66 tonnes of carbon every year, these actions collectively will reduce my emission by 2.7%! Of the 200kg carbon reduction made, 27.5% came from changing food practices. However, if I become completely vegetarian, I will be able to reduce my emission by near 4%. (Note: the calculation itself is an rough estimate! I will explain why this figure differs from my previous claim that going vegetarian or vegan could reduce emission by 10% roughly.)

This is the building in which I live and collectively we have pledged this much as shown below! 

Check it out and see how much you can save personally. This campaign is brought to you by Do Nation, which champions reducing our environmental impact through adopting more sustainable yet achievable behaviours. 

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.

British People Can Make It Happen!

Feeling defeated from the findings from the last post, I have decided to look at the situation for the Europeans and see what difference it makes if dietary changes are made to reduce meat consumption. Also, I will again try to put the findings into context when compared to the overall carbon emission and other forms of carbon mitigation strategy.

The results from this review of many studies show that the potential to reduce GHG emissions from food consumption through dietary change can be substantial in regions with affluent diet. The reduction potential seems mainly to depend on the amount and type of meat and animal products included in the diet. Diets in which all animal products (vegan), meat (vegetarian) or ruminant meat are removed have the lowest GHG emissions. See figure 1. This confirms the general consensus that going vegan is good. But how effective is this in reality? 

Percentage wise, going vegan in EU has a greater impact on its overall GHG emission than the US. The review shows that food consumption accounts for 15-35% of European climate impact whereas in the US it is less than 10%. (This is based on the following figures. The CO2 emissions per capita per year is around 0.9-1.7 for processes of production and 1.4-3.2 tons if including transport and retail. According to EEA (2012), each EU citizen is responsible for 9 tons of CO2 emission every year). If the whole of EU undergoes dietary change to adopt either vegetarian or vegan diet or even just avoid eating beef and lamb, there could be a 4-20% reduction in GHG emissions per capita. This is very exciting and promising indeed!

For example, according to the committee on climate change in the UK, we have done extremely well so far. Not only has the first carbon budget target been met, the reduction rate currently also means we may deliver even more reduction in the second and third phase. However, the projection shows that we are not on track to meet the fourth, which covers the period 2023-27. 

To be able to meet the target of fourth carbon budget, there needs to be a reduction of 594m tons of CO2 in total, which is equivalent to an annual reduction of 118.8m tons. Given the population will increase to around 70m in 2025, a reduction of 4-20% of GHG emissions per capita means dietary change could help meet 21%- 106% of the required reduction! Therefore, at least for the UK alone, dietary change is indeed very promising!

Meat Free Monday in the US! Feel good or bad?

During my last post, I promised to explore some of the dark side of switching from an omnivorous diet to ones that are either vegetarian or vegan. I have to admit, as the majority of the research articles do generally conclude that reducing meat, particularly red meat, is more environmental-friendly, that it was a bit difficult to find counter arguments. Luckily, I came across some research papers that provide a different point of view. Notably, the researches published by Dr. Capper Jude are pro-meat and her arguments do raise some interesting aspects that I have not thought of. Click here to see her series of lectures on meat and sustainability (http://wsu.academia.edu/JudeCapper). Over the next few post, I will examine critically her comments and against a wholesale change to plant-based diets. This post will focus on whether reducing meat consumption will have a significant or negligible effect upon greenhouse gas emission in the US.

According to Dr. Capper Jude in this study, she claims that movements such as ‘Meat free Monday’ will do nothing to help the environment as the reduction in US national GHG emission will only be as low as 0.3%. Let’s give her the benefit of doubt and suppose her statistics are correct, what does the reduction of 0.3% in US national GHG emission mean when put into context? The US commitment to reduce GHG emissions under President Obama's administration targeted to reduce emissions by 2020 to 17 percent below 2005 levels. Given the emission level in 2005 was 6,741 million tons, the emission would have to be decreased to 5595 million tons in 2020. Therefore, the rate of reduction will have to be 67.5 m tons of CO2 reduction roughly every year from 2005 to 2020.  In contrast, a reduction of 0.3% in annual US national GHG emission means that 20.2m tons of CO2 reduction every year. Note that the former statement is focusing on the rate of decrease while the latter is simply a reduction of constant. Therefore, from this point of view, it does seem that by going meat free Monday, there will be limited effect on reducing GHG emissions. Nonetheless, it is some progress. If the whole of US stop producing meat, following her statistics, around 141m tons of CO2 equivalent would be saved each year. This is equivalent to 63 % of the amount of GHG emissions saved by a constant increase in fuel efficiency of 5% each year from 2017 to 2025, which is kind of impressive.

Personally I find her statistics somewhat questionable, partly due to her affiliation with many meat industries and organisations, and partly because the figure she quoted from US Environmental Protection Agency (EPA 2012) only includes limited aspects through which livestock farming could contribute to GHG emissions.

Her figure is likely to be underestimated for two reasons. Firstly, as it only includes the GHG emissions from US national meat production and does not include meat that are imported from other countries such as Brazil. Not only would this increase the carbon footprint of meat consumption through increasing mileage, it also shifts environmental burden e.g. eutraphication, pollution, and land conversion to other country. However, it is known that carbon footprint weighs less significantly for meat product. Buying local meatonly reduces carbon footprint by 1-3%. Secondly, the analysis of agriculture GHG emissions only include aspects such as agricultural soil management, enteric fermentation, manure management and rice cultivation. It does not include aspects such as process of land conversion to croplands and grasslands. They amount to 5.9 and 23.9 Tg CO2 equivalent annually respectively, which are around 30m tons collectively every year. This figure pushes the CO2 saving upto 170 tons roughly, however dwarfed shyly in comparison to other sectors in the US.

So overall, with the information that I have researched so far, it does seem that going vegan has somewhat limited effect in reducing CO2 emission. 

To be honest, I am fairly disappointed by the findings so far, as much as I’d like to convince myself that eating more vegetables and less meat is helping the environment. However, it must be noted that this is partly due to the fact that the carbon emissions per capita in the US is significantly larger than other countries and the food industry does not take up as much proportion of the carbon emission in comparison. The saving in carbon emissions through having less meat is still comparable to carbon emissions in other countries. Additionally, in the UK and other countries whether developed or developing, there might be a different story to be told!