My perspective on Cowspiracy and final words

If you have read my previous blogpost, you have probably gathered that I do not like this film. Here is a summary of why.

The film through cherry-picking and exaggerating figures hijacked the voice of both climate scientists and environmental groups. It twisted the words of many interviewees and discredited many good work that have been done by the environmental groups. Its over-simplisitic and divisive narrative masked the complexity of environmental issues and dismissed the impacts brought by the fossil fuel industry.


Hijacking the voice of environmentalists and scientists

Cowspiracy accused the environmental organisations of being bribed by the meat and diary industry despite having no specific information that can be proved or refuted. It questioned the scientific consensus of the impact of animal agriculture on the environment. 

Luckily, both the environmental groups and scientists have fought back, albeit their limited power in public discourse.

Greenpeace published a blogpost stating that they declined Kip’s interview because ‘they felt sure our position would be misrepresented (as it has been for several other organisations featured in the film)’. They lamented that their decline has been ‘misrepresented as well, in an attempt to create a sensationalist conspiracy where none exists.’ 

Through a podcast interview, those being misrepresented finally had a chance to confront Kip Andersen personally. 

The Director of Food and Agriculture Program from Natural Resources Defense Council, Jonathan Kaplan, said the accusation is ‘very upsetting’, ‘completely without merits’ and felt like ‘being backstabbed by their environmental ally’. Same sentiments were shared by those who were interviewed by Kip Anderson in the documentary. 

Nicolette Hahn Niman, despite being a critic of the industrial production of meat, was very angry at Kip as he ‘had no idea what he is talking about’ in the film (with reference to the role of ruminant animal play in soil microbiology and carbon foot print and their relation to sustainability). She suggested that the whole documentary was ‘garbage’ as the whole premise of the film was based on statistics provided by a vegan dentist, Dr.Richard Oppenlander, who had no expertise in sustainability. 

There are also many scientists debunking the 51% figure in peer-reviewed journals. (Click here and here to see my two previous posts for a summary of why his figure is unscientific and false.)

Us vs them, the goodies and baddies?

Cowspiracy successfully capitalised the viewer’s sentiment of ‘anti-establishment’ against the so-called ‘expert’. 

This is the strongest message that I get from the documentary personally, ‘It is us against the world, against the powerful meat and dairy industry, against the ineffective and money-grabbing environmental non-profits. It is upto us to change the world.’ This effectively undermined the images of mainstream environmental groups and scientists, at least for those who are persuaded by the documentary. 

Additionally, the film in this way then frames both the root cause of and solution to environmental problems as one that stems from individuals, rather than the wider socio-economic structure. Kip Andersen in an interview with realnews.com said 'The solution ... doesn’t even take necessarily widespread transformation with the legal system and our politics. It’s basically just switching our diet.' Not only does this ignore the role of fossil fuel industry and capitalist neoliberal economy in the resource exploitation, it simply denies the variety of methods for environmental governance like Jones (2014) suggested, 'Diversity of incentives is the key to environmental resilience.' 

Another message it expresses strongly is that ''Meat-eating environmentalists are hypocrites.' The binary division of vegan versus meat-eaters is not helpful at all! It limits the the reach of environmentalism and masks the complexity and vast array of environmental issues. A one-size-fit-all solution is not realistic and may have great unintended environmental, social, economic, and health impacts. I believe to make an visible impact and change to current policies, the movement must be inclusive and accessible to all, one that incorporates social and economic aspects and the spatial-temporal dimension of environmental issues. Further, going vegan does not necessarily mean that your personal carbon footprint is lower than the omnivores if you leave your heater on 24-7 or takes cheap flights frequently. There are a whole lot of things you could do to make the environment better: not driving a car or taking an airplane, reduce unnecessary shopping, finish all your food, advocating for more environmental policies etc 

So how should we deal with this? 

• Educate people about the uncertainty of climate science and concept of precautionary principle. Personally, I don’t think the public are well-versed with the complexity of the issue, one that is environmental, social, economic and political. 
• Educate people about the linakge between fossil fuel and agricultural industry. See them as inter-related rather than two separate entities. 
• Encourage greater participation among scientists in the public discourse. I understand people are busy with their lives and all. We don’t all have time to argue with people online but in my opinion it could be the most effective way to empower the scientific community and not let its voice hijacked by some click-baits-manufacturing, low-quality journalism.
• Adopt a different policy framework to combat climate change. One that holds the government, the fossil fuel and its related industry and the wider social structure accountable, not one that sees individuals as both the only 'mean' and 'end' to climate change (Barr et al 2011).

Final words

As both an environmentalist and a food enthusiast, I truly appreciate the choice of food available at my dinner table. Now that I have covered a range of topics (carbon footprint, water usage, food waste) with regards to food and vegan/vegetarian food, I realised how complicated and politicised the issue can be. There is indeed no simple solution to environmental problems. Nothing is quite as simple as it seems. The best practice could vary geographically because of different environmental, social and economic background. 

But hey, I guess I will do what I can, by eating more veggies, less meat, producing no or very little food waste on an individual basis. I will also continue with advocacy of more sustainable lifestyle through do nation, campaign for a wider political change.

5 facts about food waste and consumption you should think about when having dinner today

All the talks about dietary choices aside, here are some much less controversial methodd of reducing personal food-related carbon emission—eat all the food you buy and in an appropriate amount. Below are some astonishing facts about global food waste: 

1. Using data of food waste volumes and emissions factors from the 2011 Life Cycle assessment, the associated carbon footprint approximates 3.6GtCO2 (4.4GtCO2 if land use change included).
2. According to the 2011 FAO assessment, the food wastage arising from all stages of food supply chains is equivalent to a third of the total food production. 
   
3. Consumers on average are responsible for 37% of waste occurred.(Source: Food and Agriculture Organization of the United Nations, Food Wastage Footprint Impacts on Natural Resources, 2013.)
   
   
   
4. Hall et al (2009) modelled the calories wasted for people in the US and suggested that it has risen by 50% within 35 years. Interestingly, the average body weight also increased by nearly 14% in the same period.
5. Among all food types, surprisingly fresh vegetables and salads and fruits are among the highest on the rank for weight of food waste. But personally, I have to admit it could be a bit challenging to finish a whole package of salad. Sometimes I even forgot about its existence or I am just not in the mood for salad.
   
   Note.
   

I will make sure I finish all food in my plate! I promise!

Cowspiracy: politics of climate science. Some thoughts from the academics (2)

Following on from the previous post, here is the second question that I asked:

Question 2: What do you think the scientific community should do in response to the unscientific and misleading claim of Cowspiracy or any other similar contents in general?

Dr.S:

Within the scientific community, most people would simply just ignore it. It’s like telling people movies such as ‘The day after tomorrow’ and ‘2012’ do not make scientific sense.

Professor V:

Statistics are often conflicting. However, IPCC should serve as a good starting point for cross-referencing as its one of its main goal is to establish a consensus (despite often being criticized to be conservative).

We know that methane has increased dramatically in the atmosphere in the past few hundred year due to land use change, natural sources, and intensification of agricultural activity. However, some details are still debate. It is not realistic to expect scientist to come up with one single answer such as one proposed by the documentary. As we all know that there is no one single answer for ways of approaching climate change, I’d imagine the scientific community would most likely discredit the idea that by simply going vegan, climate change will be mitigated.

Dr.R:

The scientific community attention to the impact of livestock farming and lobby government on it. However, they should also condemn the over exaggeration in the statistics used by the documentary.

Professor Anson Mackay:

Uncertainty is an area which the scientific community needs to target. Scientists have duties to not exaggerate but to report on the accurate and reliable finding.

My thoughts:

It is again very interesting to see a diversity of views being expressed. Dr.S thinks most scientists will not be bothered with such issues while the others implied that scientists should put efforts into debunking unscientific claims. This led me to think about whether it is true that most scientists do not actively speak out against these controversial subjects as suggested by Dr.S.

Conservatism among scientists?

According to Brysse et al (2012), it suggested that most scientists are quite conservative in terms of the projected impact of climate change, unlike the ‘alarmist’ image some media opinion pieces portrays (See the text box below for an example). It suggested that many key aspects of global warming (such as rising surface temperature, carbon emission and sea level), have been under-estimated in the IPCC report. For instance, despite the important role of permafrost and its potential melting in the global carbon cycle, it was not included in the IPCC projections (Allison et al, 2009), potentially leading to significant underestimation of climate change. Brysse et al (2012) concluded that there is a systematic conservatism in the prediction of climate change.

(Despite some news articles often labelled climate scientists as ‘alarmist’, they are actually rather conservative in their claims. For example, this news article criticised the legitimacy of climate scientists by claiming that scientists in 1970s were warning the public of global cooling. It stated ‘Man was blamed for global cooling as he is blamed today for global warming’. Media coverage like the one above not only oversimplified the science but also discredited the legitimacy of the mounting scientific evidences supporting anthropogenic climate change.)

BUT is the previous analogy applicable to Cowspiracy? On one hand, based on the conversation that I had with Dr.S (who is an expert on politics of climate science) and the fact that 3/4 interviewees would like to remain anonymous, they suggested an degree of conservatism. On the other hand, this is partly due to the fact that they are not expert on the subject of food sustainability nor have they watched the documentary. Additionally, although very few papers/ blogposts/ responses have been published with regards to the false statistics used in Cowspiracy, this could be attributed to the limited viewership of this documentary and its associated literature. Therefore, the answer remains inconclusive.

The scientists seem to lack power in influencing the public discourse and their opinion on climate change. They are often misrepresented and taken out of context (as the example above illustrated and also in Cowspiracy). This is especially true in the realm of post-normal science where ‘facts are uncertain, values are in dispute, stake are high, decisions are urgent’ (Funtowicz andRavetz 1993). People who have different values and stakes from the scientists and environmentalists will naturally reject or distort the idea of anthropogenic climate change in the public discourse. For example, Boykoff’s(2008) analysis of the discourse of UK’s tabloid on climate change showed there has been increasing number of sensational and exaggerated reports and more ‘opinion-driven’ pieces with ‘satirical tones’. Both served to undermine the legitimacy of scientific assertions. 

Cowspiracy: politics of climate science. Some thoughts from the academics (1)

Cowspiracy, as its names implies, is a film about conspiracies. It alleges that major environmental non-profits like Greenpeace and Natural Resources Defense Council are ‘hiding’ the truth to climate change to us, the public as they secretly take money from the powerful meat and dairy industry. The co-found and co-producer of this documentary, Kip Anderson, describes the actions of the environmental groups as ‘fixing a leaking faucet or cleaning windows in a house that is burning down’ and ‘not smoking next to asbestos to reduce the chance of getting lung cancer’ in an interview with Climate One, an environmental podcast programme. His accusation was subsequently challenged by many others, including those he interviewed in the documentary.

Towards the end of the interview, one audience even questioned his ethics, whether that be in documentary-making or science in general. This really struck me and led me to think about the ethics of documentary-making and making scientific claims. What discerns right from wrong? At which point do you cross the line? What are the role of politics in environmental science? These were some critical questions that I have thought long and hard. To gain a better understand, I interviewed a few environmental academics at UCL Geography department. (Disclaimer: They have not watched the documentary and were simply asked some general questions after I briefly described the film to them. The statements below have been paraphrased.)

Question 1: What do you think of the wider implication of this documentary on climate science and policy?

Dr.S:

Well as I haven’t heard of this documentary, I’d say its impact is likely very limited. Even if it is popular, I think because the way they portrayed the environmental issue makes it easy to discredit for the following reason:

• Too much control. People do not like being told what to do. An abolitionist approach of going full vegan makes people think ‘well if I am not vegan and if that means I am not an environmentalist, I may as well not be environmental friendly at all.’
• It just seems like another scaremongering documentary. People are normally quite informed of issues like climate change.

Professor V:

I agree with the documentary in the sense that agricultural sector play in terms of its contribution to climate change and environmental impact. There are issues to do with methane produced from ruminant animals. Land use change associated with farming are also important. It may generate more attention within the scientific community and this may translate to some policy action.

Dr.R:

As the public is not well-informed of climate science, they may take the documentary at its face value. And if they think it is solely the duty of environmental groups to combat climate change, it is very likely that they would stop donating to them. However, it is debatable on how this documentary would translate into policy actions

Professor Anson Mackay:

There are similar documentaries in the past as well. For example, the famous ‘The Inconvenient Truth’ documentary by Al gore. There were obviously some scientific inaccuracies and generated some controversies. But it did successfully install environmental awareness in the public.

However, there is likely to be limited impact as there are many social, cultural and economic barrier in terms of changing one’s diet. Additionally, people generally do not think about the production of food source or linking it to animal slaughter.

My thoughts:

It is very interesting to see a diversity of views, even within the scientific community. For example, Dr. S thinks most people are well informed of climate science whereas Dr. R thinks otherwise. Prof V think it ‘may’ lead to some policy action whereas Dr. R thinks it is debateable, contingent on what role do the public perceives themselves, government, environmental groups, and scientists play in combatting climate change.

Although not included in the statement above, during the conversation, all four unanimously agreed that it would be difficult to encourage dietary change among people, especially when Cowspiracy took such an ‘all-or-nothing’ stance.

   

Lombardini and Lankoski (2013) also expressed similar views after assessing the success in promoting plant-based diet through the implementation of mandatory vegetarian day in the Helsink Schools in Finland. They found that in the short-term, most student responded negatively in forms such as decreasing participation in school lunches, decreasing amount of food taken to plate and increasing food waste. However, there were improvement in the medium term. The only non-compliance left was the decreased amount of food taken to plates. The researchers suggested that to encourage dietary change, it is important to understand the causes of non-compliance, as opposed to what Cowspiracy implied (i.e. people who consumes meat are unethical and not environmental friendly). They recommended that providing vegetarian options would be preferable if the cause of non-compliance was due to psychological reactance. Also, menu development could also help reduce friction in dietary transition. Moral suasion and information campaigns work most effectively in cases where people disagree with the objectives and effectiveness of plant-based diet in promoting sustainability.

As an environmental activist, I support the idea of adopting a more sustainable diet, whether that be vegan/ vegetarian diet, or simply reducing food waste. However, I would definitely not side myself with the idea that ‘people who consumes meat are unethical and not environmental friendly’ as I think it could potentially push people into thinking there is no point in doing other environmental-friendly actions, as Dr. S rightly pointed out. Secondly, I think that many people are not that well-educated in terms of climate science (just scroll through the comments on any climate-policy-related posts on facebook, and there are always people who label it as ‘liberal propaganda). They may easily be misinformed, especially the idea of a conspiracy is so eye-catching and sensational. Lastly, I think this is not just a direct attack on environmental NGOs but also one on the scientific community. The scientific community should leverage on their credibility to speak out loud and hard against any misinformation such as Cowspiracy.

To be continued. 

Cowspiracy: fact-checking (2)

With the outlandish statistics and claims made by the documentary Cowspiracy, naturally people would want to know whether the content is scientifically true or a vegan propaganda. This is especially true this year, where the word of the year declared by Oxford dictionary is ‘Post-truth’. Personally, I have to admit nowadays I find it increasingly more difficult to differentiate whether a claim is fuelled with ventured political motives or backed by concrete scientific evidence. However, through deconstructing the so-called 51% GHG emission by agriculture sector statistics, I have partly restored some faith in my ability to critically analyse the validity of the content. Admittedly, have it not been part of an assignment, I would not have the time and effort to look into it and could very well have been persuaded and simply take what the documentary said at face value.

Confronted with the enormity of information and statistics (some of which are contradicting) during my research, whether in mainstream media or peer-reviewed scientific journal articles, I decided to turn to reviews that systematically evaluate the environmental impact of different dietary choices. Particularly I found two papers (Hallstromet al, 2014;) that are very helpful in providing a more systematic assessment of the environmental impact of different dietary choices. They offer a much more holistic view of the impact of different food and their production and consumption cycle and, most importantly, explained the variation of statistics that I have encountered.

Let’s lay down some facts and figures first then. Hallstromet al (2014)’s investigation of 14 peer-reviewed journal articles showed that out of all the different dietary choices, adopting a vegan diet is indeed the best way to reduce carbon footprint. See Figure1 and Table1. According to the researches that are included in this study, there is a potential of reducing the carbon footprint by 20% - 55%. Although huge variation exists, most studies do point into the same direction. In Auestad and Fulgoni (2015), their review also suggested similar result. For example, Berber-Lee et al (2012) suggested that the UK could reduce its food-related emission by almost 25%, along with some potential health benefit if everyone were to adopt a vegetarian or vegan diet. Aston et al (2012) expressed the same view as well. (Phew, I am glad the argument on that is settled, at least in the context of UK.)

However, there are many caveats in the previous paragraph.

Firstly, it is important to note the definition and language used in the studies. For example, the 25% reduction in Berber-Lee et al (2012) is referring to food-related emission, not emission-per-capita and if the two different terms were to used interchangeably, two very different stories would be told. It begs the question of how much carbon emission of each person is attributed to food-related activities. A vegan who overconsumes with many food waste vs an omnivore who eats appropriate amount of calories needed and minimise food waste could make the comparison of carbon footprint a lot more nuance than it first appears. Therefore, it is important to understand the difference in the units used for dietary comparison. 

Secondly, as both reviews rightly pointed out, there are inconsistencies in methods used to determine GHG emission. Although most studies have adopted life cycle assessment (LCA) as the primary method to assess the carbon footprint of different diets, the ‘absence of LCA databases for representative foods in the marketplace’ means methodologic variability exists among different studies. For example, in 22 and 23, their data were extrapolated from other countries as no domestic data available. Additionally, different aspects of food production were included in many studies, leading to different results and interpretation. Should we include the GHGe from only farming itself like in 16, farm-to-retail like in 12 or farm-to-home like in 13 and 27 (i.e. including aspects such as transportation, storage, methods of cooking, and amount of food waste)? Therefore, we have to be very careful when making comparison and not extrapolate one statistic or study done in one geographic location into another.

Thirdly, there are indeed many other aspects that the measure of carbon footprint alone does not encompass. What about land use, water use, chemical pollution, food waste, food miles of different agricultural products? For example, despite Cowspiracy’s claim that cow milk requires more water than almond milk, some argued that as cow milk largely relies on green water (i.e. water from rainfall in the forages that cows are consuming) which cannot be consumed by human directly without treatment, it is actually more sustainable than the former.

Overall, I think it is dangerous to make reductionist assumptions about the benefits or the harm of a particular agricultural product. There are so many different ways of unit representation (which are confusing to geographers/ scientists already, let alone some journalists whose aim is to make sensational headlines and maximise their views as opposed to providing scientifically qualified content), so many aspects of food life cycle and their respective environmental impacts. We ought to be more cautious of the sensational headlines and claims, especially in this day and age where so many fake news prevails. 

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.