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What we eat, and meeting our climate change commitments

What we eat, and meeting our climate change commitments

We are pleased that Jennie Macdiarmid, the Rowett Institute is able to discuss the links between what we eat and our climate change commitments. This post was originally published by the Scottish Parliament’s Information Centre (SPICe), who commissioned SEFARI to write a series of blogs to stimulate debate on this issue. SEFARI research takes a collaborative approach and looks at this complex and challenging issue from multiple perspectives, including improving animal health, as well as the role of precision agriculture and cropping systems in reducing greenhouse gas emissions. 


The dietary choices and habits of a person cannot be divorced from climate change, biodiversity and ecosystems, or the more common focus, the prevalence of diet-related diseases (e.g. obesity, type 2 diabetes, heart disease and cancer).

As regards climate change, it has been estimated that the food system (including e.g. agricultural production, processing, distribution, retail, cooking and waste) accounts for 20-30% of all UK greenhouse gas emissions (GHG).

Scotland has ambitious climate change targets, and these are set to increase through the Bill, and in the context of the 2015 Paris Agreement which aims to limit the increase in global temperatures to less than 1.5°C.


Emissions reductions

Historically, the focus on how we reduce emissions has been in other areas, such as the energy sector. Changing what we eat, now has to be one of the priority areas for reducing emissions. Action across the food and agricultural sector has predominantly been around finding technological solutions to cut emissions, and to decrease food waste. Studies, however, have shown that technological solutions alone will not be sufficient to meet our targets. Adopting “low GHG-intensive foods” and changing diets to those that are “less resource-intense” are some of the mitigation actions proposed in the most recent IPCC report.

The most GHG-intensive foods are animal products because of the high emissions associated with livestock production. A large amount of Scottish Government funded research is being carried out by SEFARI and others to find ways to reduce emissions in livestock production, including huge innovation in livestock management, breeding and on disease control. Nevertheless, this does not get away from the need to look at our meat consumption. Interestingly, a number of countries, including the Netherlands, Sweden and Brazil have revised their dietary guidelines to incorporate advice on reducing the environmental impact of diets (i.e. reduce meat consumption).

It is understandable that this may be an unpalatable option for many in society, because it has economic implications and goes against the tradition of having meat in the diet, as explored by Quality Meat Scotland (QMS), the National Farmers Union Scotland, and the National Sheep Association in their written submissions on the Bill. QMS states:

"It is far too easy to forget that agriculture is about food production and that food production is a non-discretionary activity. It is also important to recognise the role of food production in sustaining employment in rural areas, and its contribution to the wider Scottish economy and balance of trade. […] The risk of landscape degradation that would accompany the end, or even the substantial reduction, of livestock production in Scotland similarly cannot be ignored."

Knowing the environmental pressure and health implications, however, does not seem to be sufficient to convince a lot of people to eat less meat. Many people simply enjoy eating meat, but some also have a wider concern about the impact of eating less meat on their health, namely whether they would have enough protein in their diet. Empirical evidence shows that there would not be insufficient protein in the diet as a result of eating less meat. Is there, therefore, a misconception among the public and others of the need to find protein replacements for meat, whether plant-based foods or novel foods such as insects and laboratory-produced meat?


Protein intake

The fact is that people in the UK, including vegetarians, consume significantly more protein than they need. A recent study that showed the quantity of protein available to eat in the UK is about double the amount required to meet the population’s dietary requirements, and even if all meat were removed the supply would still be about 120% of requirements. This suggests that protein is the wrong nutrient on which to focus in terms of shifting to healthy and climate friendly diets. In the UK many people do not eat sufficient fibre and therefore replacing meat with plant-based and wholegrain foods would be beneficial for health as well as reducing emissions. Meat is a good source of iron and zinc and although these are also found in plant-based foods, should more attention be paid to these nutrients?

The proposal to eat insects as an alternative to meat is an interesting example of where this option has been considered from a narrow perspective. Insects have been described as a convenient, sustainable, economic and healthy alternative source of protein. While the impact of scaling up to commercialisation of insect production sounds to some like a viable alternative to livestock production, little is known about how much this would really reduce emissions since it would depend on the production system and the amount needed to feed the population. More importantly, insects are bio-accumulators and depending on what they are fed, they can accumulate a range of heavy metals and contaminants, such as cadmium, lead and arsenic. The quantity in which insects would need to be eaten questions the health impact of potentially ingesting such toxins. People would also need to be persuaded to eat them. Any alternative needs to be looked at from multiple perspectives.


Dietary change

What we choose to eat can have multiple consequences and therefore there is the risk of unintended consequences if action is taken with only one driver in mind (whether that be climate change or health). A simple climate compliant diet would miss all the other aspects of sustainable diets, such as health, affordability, accessibility, social and cultural acceptability and other environmental impacts (e.g. land use, water, biodiversity). If the sole aim was to reduce emissions then a diet with energy intake predominantly from sugar would be effective since, relative to other commodities, its production has lower emissions. This may be acceptable to some people, but it is not something recommended for a healthy lifestyle. It is true that a healthy diet can be a low GHG diet, but equally a healthy diet can have high GHG or a diet low in GHG can be unhealthy. So, there is no doubt that diets need to change but this can only be achieved if a holistic approach is taken. No one denies that this will be challenging, especially reducing meat consumption, but doing nothing to change dietary intakes is not an option if our ambitious targets for reducing emissions are to be met.


Professor Jennie Macdiarmid, The Rowett Institute, University of Aberdeen.