Milk Coffee: Oat milk

Dairy milk tends to be the default option for white coffees. However, in 2019, there has been a 37% decrease in dairy milk consumers since the 1970s (Held, 2020), suggesting the rise in awareness of alternative milk options. Specifically, oat milk has been gaining increasing attention in the cafe scene due to its superior taste and texture against other alternatives. Sales of oat milk have risen 71% in just a year, from 2017 to 2018 (Aydar, Tutuncu, & Ozcelik, 2020). This poses the question: are there ramifications as consumers switch from dairy to oat?

Based on Poore and Nemecek's (2018) study conducted in 2013, oat milk uses significantly less land for production as compared to dairy, suggesting that the area for non-point source pollution via fertilizers and greenhouse gas emissions will be lower.

Figure 1: Environmental footprints of dairy and alternative milk. The data is based on Poore and Nemecek's study. Source: Ritchie, 2022.

This was supported by Roos, Patel, and Spangberg (2016), who did a more comprehensive study on oat milk production's impacts on the climate. Their study found that there is a 16-41% lower direct greenhouse gases emissions from energy and fertilizers usage, and the absence of livestock cultivation. However, the risk of eutrophication between oat and dairy milk appears to be similar given the same amount of land cultivated. Additionally, as oats are made of organic matter, the necessary process of digestion of oats by the enzymes produces 21-37% more ammonia emissions than dairy milk productions during storage and distribution. This increases the ecotoxicity impact on the environment. Fortunately, the ecotoxicity impact from oat milk production can be mitigated via the cultivation of grass-clover. This is difficult for dairy production as cows are ungulates and their hooves will compact the vegetation when they graze the fields, and barns limit the amount of space available for vegetation.

Overall, it seems that oat milk production is indeed a better alternative for the environment as compared to dairy milk, as lesser land can be used to produce the same amount of both kinds of milk. This means that oat milk generates fewer emissions and pollution risks than dairy milk. 

Also, those who enjoy specialty coffee, but are constrained by dietary restrictions, should definitely consider oat milk as its flavour is not overpowering, and it does not coagulate as compared to other alternative milk. Giving the coffee a better taste and smoother texture.

Milk Coffee: The heart of pollution in the dairy industry

Regardless if it is a flat white, latte, cappuccino, or a kopi-C, kopi, 3-in-1, what is are the two ingredients that are common in both drinks? Coffee, and milk. As I have drilled on continuously about the causes of pollution in the coffee industry, I would now diverge to a complementary product to coffee. Milk.

According to Dr. Weiss, nitrogen forms bulk of a cow's diet, and only about 33% of the nitrogen intake retains in the cow's system or secreted as milk. The remaining 67% gets excreted as manure. Due to the high nitrogen content emitted, manure was found to be the primary cause of pollution in the dairy industry.

Manure can pollute the atmosphere as it releases ammonia, which can react with other pollutants in the air to form NH4+. NH4+ compounds contain aerosols which are harmful to our respiratory systems, and contributes to global warming. They can also travel long distances, which increases the expands the area of vulnerability to a global scale. (source). However, the volatility of ammonia in the atmosphere depends on the:

-   surface area

-   air movement

-   temperature

-   pH

of the manure (Weiss). Hence, while the ammonia released into the atmosphere via manure is pollutive, complex conditions need to be satisfied for atmospheric pollution via ammonia to be considered as serious.

Besides polluting the atmosphere, manure releases ammonia which pollutes the hydrosphere too. Grossman (2014) quotes the EPA, who found that a cow can generate almost 25 times as much nitrogen form manure as humans can from sewage. This is concerning as the nitrogen either leaches into the soils, which gets incorporated in the waters, or it is directly disposed of in the waters. Nitrogen is a highly potent pollutant in waters as it is a limiting nutrient. In other words, it controls the growth of organisms in water bodies as there are other reactants in the waters that are more abundant. Excess nitrogen in waters can promote the growth of cyanobacteria and algae, which creates anoxic environments in the water bodies, threatening the aquatic life.

Hence, as the dairy industry contributes expansively to pollution, is it perhaps time to consider milk alternatives?

Milk Coffee: Our carbon footprint

There are many ways to prepare coffee at home. Drip bag, capsules, from a packet or pre-packed. They all taste different, but taste is not the only differentiating factor. Each choice has a different carbon footprint as well. 

A study conducted by the Department of Environment Quality in the state of Oregon compiled four different pieces of research that estimated the carbon footprint derived from the different preparations of coffee. The simplified version is of the following:

Image source: Heller, 2017.

From the study, it appears that milk-based coffee contributes the highest carbon footprint of about 0.22 to 0.24 kg of carbon dioxide equivalent per serving. As we know, milk comes from cows, and cultivating them contributes high levels of carbon emissions.

These emissions come from the clearing of land to cultivate the crops needed to feed the cows, and the cows themselves. It was found that cows are responsible for 15% of all anthropogenic greenhouse gas emission (Bryce, 2020)!

As we know, the clearing of land reduces carbon sinks, and the increase in dairy productions increases the carbon emitted and hence trapped in the atmosphere for at least 300 years. Alas, black coffee is not a perfect subtitute for milk coffee. This suggests that dairy production will stay, and if nothing is done, the existing atmospheric pollution will only worsen.

Hence, the question that remains is: how can we reduce our carbon footprint, besides switching from a cafe latte to an americano? 

Ways to Reduce Coffee Pollution: Biogas in Ethiopia

Wet or dry, coffee husks are bound to be removed during the cherry's processing stage. As one of the largest countries generating coffee husks, Ethiopia typically found coffee husks useless and dispose of them in the waterways, thereby introducing toxic substances into the environment, like caffeine and tannin. But are coffee husks really useless?

Du et al. (2021) seemed to suggest otherwise. According to their article, if coffee husks are properly utilised, they are found to have a high potential to produce biogas, which can be used as a renewable energy source. Currently, Ethiopia is highly reliant on biofuel for energy, and wood alone make up 69% of its biofuel source (Benti et al., 2021). While wood was seen as a renewable energy source in the 2000s, it was later found that biofuels may be releasing more carbon instead, due to deforestation and land-use change (Climate Policy Info Hub), signalling that Ethiopia should find a more sustainable source of energy. Du et al.'s findings will hence be important to build the resilience of Ethiopia's energy sector.

As coffee husks are highly organic, the biogases are produced via the anaerobic digestion of the husks. This will generate methane, carbon dioxide, and a trace amount of other gases. While the products of anaerobic digestion sound dangerous for the environment, these gases would be captured in a facility, which can be used to generate electricity instead of escaping into the atmosphere.

However, the efficiency of biogas as an electricity source is rather low (Damyanova & Beschkov, 2020), suggesting that biogas cannot effectively replace the majority of energy generation in Ethiopia. While the lack of efficiency may seem like a put-off, the energy generated by biogases are still adequate to power small appliances and to use as a heat source. This may be more useful and cost-efficient for the rural communities who require less electricity than the urbanites, anchoring its importance in rural Ethiopia.

Coffee at Home: Are coffee pods problematic?

Since the popularisation of Nespresso coffee pods in 1988, coffee consumers have had the luxury and convenience to enjoy a cup of coffee almost instantly and comfortably in their homes. Despite the proliferation of coffee pods from alternative brands following the loss of Nespresso's coffee pod patent, Nespresso pods remain the go-to for coffee pod consumers. However, Nespresso pods are coming under scrutiny in the 21st century, as there has been a growing awareness that the excessive use of coffee pods are polluting the environment, with many of them ending up in landfills instead of proper recycling facilities (Grant, 2020). 

Figure 1: Nespresso pods end up in landfills as they are improperly disposed of. Image source: Huntsdale, 2019.

This is a shame as Moskvitch (2019), who corroborated the finding of different researches, found that coffee pods are made of materials that are highly recyclable. The Nespresso pod, for instance, is made primarily of aluminium, which is a metal that can be easily melted and reused repeated. The catch for Nespresso pods is that they contain a silicon layer, which requires specific technologies to remove before recycling can take place. As such, consumers using Nespresso pods are required to return the pods back to Nespresso's collection points, should they wish to recycle.

Expectedly, recycling rates are low. In 2018, in the UK alone, 42% of coffee pod users throw the pods away after use. This is in spite of Nespresso's efforts to expand its recycling efforts to reach 100% recycling rates by 2020 (the goal was not achieved), by increasing its global capsule recycling points (Grant, 2020). Evidently, besides making the recycling facilities convenient to consumers, awareness of such facilities must also be strengthened. Additionally, while Nespresso wishes to define their capsules through the silicon layer embedded in their capsules (Moskvitch, 2019), removing the silicon would make the capsules more recycle-friendly, as typical recycling plants will then have the capacity to recycle these pods.

In essence, to improve recycling rates and reduce pollution of Nespresso coffee pods, the mindsets of both consumers and the Nespresso company need to change. Consumers have to be more active in recycling, and Nespresso needs to forgo its ego so that its coffee pods can be easily recycled.

Are International Guidelines Useful in Preventing Pollution?

In this special titleless series, we explore the methods suggested by the Food and Agricultural Organisation (FAO) to increase coffee yields through sustainable means. 

The video describes 5 key points:

1. More efficient use of resources 

2. Protect the environment from degradation

3. Achieving more resistant coffee crops

4. Integrate other agricultural activities

5. Governmental facilitation

Coffee farms are usually located in developing countries (figure 1). Without discounting the expansive agricultural knowledge that the natives in these countries have, new farming technologies must be taught to the native farmers in order to cultivate coffee plants that are less pollutive or adopt practices that can reduce their carbon footprint. 

Figure 1: Countries found along the coffee belt. Source: Bean Poet

This is where (4.) comes into play. Intercropping, for example, is found to have a positive impact not only on the farmers themselves but also on the environment. In Vietnam for instance, the founder of a high-quality coffee-bean farm actively promotes intercropping as a way to create more carbon sinks, as monocropping is reported to contribute to 70% of the carbon sources in agriculture (Tartarski, 2019). This is further backed by Liu et al. (2016), whose study agreed that diversifying crops can reduce a farm's carbon footprint by up to 315%.

While "talking" is easy, doing is hard. Governmental facilitation is often needed to enforce regulations to reduce pollution throughout the coffee production network. However, such enforcements are not always effective. Coffee farming units in Karnataka for instance, are found to excrete high amounts of pulps and wastewater that are high in biological oxygen demand. Laws were passed to force these plants into adopting a wastewater treatment facility in order to continue operations. However, such intervention increases the cost of production, which induces farmers to exploit the environment in order to recoup their losses (Damodaran, 2002). While this example shows a poorly executed government regulation, hope is not lost as international pressure seem to be a more viable approach to induce positive change in plantations. For example, the farmers' initiatives to reduce chemical use and maintain good environmental conditions, in light of sanitation requirements set by trade countries (Damodaran, 2002).

To answer the overarching question, international guidelines are useful as a compass as they provide vague directions to reach the ideal destination. However, they are not maps, as they do not provide specific directives. In essence, these guidelines are useful when a country's context is considered.

Coffee to Go: The Disposable Replacement

Takeaway cups provided by cafes are typically made of paper or plastic for practical reasons. Perhaps, the biggest reason being their cost-effectiveness. However, in a cafe's pursuit of cost savings, it brings about a larger opportunity cost: the increasing amount of waste generated that, in the grand scheme of things, pollute the different spheres of the Earth. In the previous series, we explored some alternatives to disposable cups usage (biodegradables, reusables etc.). However, each has its own set of problems, like the differentiated waste treatment required, and the low take-up rate for reusable cups. This begs the question: are there other ways to reduce our reliance on disposables, without the need for new technologies?

The simple answer is yes. Like many other sharing platforms that we are familiar with, cup-sharing has been proposed as an alternative to combat our issue at hand. According to Song, Lee and Jung (2020), countries like Germany, some UK countries and South Korea have attempted cup-sharing services, and these services have shown signs of improving the current plight. The article was based primarily on a South Korean University's '0U Cup' cup-sharing program, and their takeaway from the project is that the coffee-to-go scene has to change in order for people's behaviour to change. In other words, cafes have to initiate cup-sharing as a default method of takeaway, and it must be made a trendy effort for the long term success of such sharing services (Song, Lee, & Jung, 2020).

Having a default option (the shared cup) and making the service trendy have to go hand in hand for the cup-sharing to be effective, as people may be repelled by the notion if they are forced to do something, and this is where societal pressure comes in to keep behaviours in check (Croes & Bartels, 2021). This is evident from the high average return rate of 75%, and the fact that cups were generally returned to the cafes deposit box, despite there being other boxes around the campus. 

Given the right conditions, cup-sharing services thus seem like a viable alternative to disposable cups as it saves the cost of restocking disposable cups whenever they run low, and also reduce wastes littered around public spaces and accumulating in landfills. While the cup-sharing service mentioned was only a mini campus project, it would certainly benefit the environment should it be expanded to a wider scale.

Coffee to Go: Bring your own tumbler

Previously, through James Hoffman's video, we peeked into the impact that paper cups can have on our environment should we dispose of them improperly. In his video, he commented on the different alternatives to paper cups, such as bringing our own tumblers, and using porcelain or biodegradable cups. However, he also implied that it is our habits that must change, should we desire a positive and substantial impact. While that is undoubtedly true, I am curious about the public's willingness to adopt a greener lifestyle by switching to reusable cups instead of paper when they takeaway coffee.

Working in a café, I have served many takeaway coffees. While there are customers who bring their own tumblers on a regular basis, many times, paper cups is the default choice. The café where I worked started selling reusable cups a year ago, and there were some customers who bought it, perhaps in their attempt to go green. I remember that there was this regular customer who asked if she could leave her tumbler in our café and we use it every time she takes out coffee. We agreed, and this positive change happened for at least a month or two. Alas, she came back without her tumbler, and we returned to serving her coffee in paper cups.

This is not a unique case as Lee (2015) behavioral studies found that among the 100 people he surveyed, 84% knew about the pollution that paper cups can bring to the environment, but only 33% bothered to use their own tumblers. The prevailing reasons for not using tumblers are inconvenience and that uneconomical. This suggests that there is a pressing need to change people's perspective of tumblers, as in a circular economy, every paper cup we throw away, comes back to us in a negative way.

How then can we change this reliance on paper cups? Song, Lee and Jung (2020) proposes that strategies can adopt a 'default option' and 'bandwagon effect' approach to change consumers' behaviors. This will be further explored in the next post.

Coffee to Go: Are we really recycling?

Paper cups have been widely used in coffee shops and cafes to take hot drinks away and drink on the go. It is estimated that 16 billion cups are thrown away globally per year, which wastes 6.5 million trees and 4 billion gallons of water annually (from Greenmatch). In the video below, James Hoffman talks about the necessity for paper cups in the coffee industry, while cautioning viewers of the dangers when we over-rely on them.

To summarise the video, some key takeaways are:

• Proper disposal methods are needed to remove the plastic lining within the paper cup before recycling. 
• Recycling companies without the capacity to remove the linings throw the paper cups into landfills.
• The UK government proposes to reduce paper cup usage via a "latte levy", where takeaways coffees are charged an extra 25 pence
• Suggested alternatives to paper cups are porcelain cups, reusable cups (tumblers), and biodegradables. However, these alternatives are plagued with their own problems.

The first two points are the most interesting. Paper cup manufacturers are indirectly contributing to pollution when they print recyclable signs on the cups, as the signs are misleading for consumers, and retarding the recycling system. Paper cup manufacturers seem to be green-washing their cups, as they do not explain the conditions to meet before the cups can be recycled. Consumers then feel environmentally responsible when they throw their used paper cups into the recyling bins. When improperly disposed, the paper cups in the bins, can contaminate the recyclables, stripping away their potential to be recycled. Eventually, these wastes end up in landfills, which generate heaps of methane that pollute the atmosphere. As such, the lack of consumers' knowledge and the lack of manufacturers' initiative to educate results in a positive feedback loop of atmospheric pollution, due to the additional methane produced from waste that could be recycled.

Coffee Farming: Pesticide

Persticides are often used in coffee plantations and unfortunately, the amount of beans produced is directly related to the amount of pesticide used when cultivating the coffee trees (Suoto et al., 2018). de Queiroz et al. (2018) also found that pesticide consumption increased by more than 90% on a global scale, of which is partly derived from coffee. Pesticide use can have detrimental effects on humans and the environment, which we will touch on today.

de Queiroz et al. had did a study on the sustainability of pesticide use in coffee production. Out of the 59 active ingredients that are detected in pesticides, the team found that about 37% of ingredients are toxic to humans and animals, and 47% to the environment. The most common ingredients belong to the organophosphorus class and the pyrethroid class. Poisoning from organophosphorus pesticides are said to cause respiratory failures, seizures, muscle weaknesses, and comas (Vale, 2015), and pyrethroid pesticides are said to cause sore throats, abdominal pain and nausea (Bradberry et al., 2005). Environmental impacts include the acidification of soils and increasing resistance to weed species (Mulla et al., 2019).

Alas, pesticide poisoning is typical in countries producing coffee. In Brazil, the world largest producer for instance, the Human Rights Watch (2019) reported that exposure to pesticides is reponsible for at least 100 deaths in a rural school within the state of Parana alone, causing one to wonder the extent of impact pesticides can have on the whole of Brazil. 

Besides direct exposure, the impacts of pesticide pollution can be felt globally. Due to the trade networks established, chemical laden coffee beans are transported and consumed easily worldwide. Toxins may bioaccumulate within those who consume the coffee made from these beans, which endangers their health in the long run.

While there are detrimental heath impacts brought about by coffee farming, it is difficult for coffee addicts to abstain from coffee. Perhaps supporting organic or sustainbuluty certified beans would be the way to go.

Ways to reduce coffee pollution: Composting

The time to reduce coffee pollution is not confined to its production stage. After brewing a cup of joe, the next likely course of action would be to throw the coffee grounds (CG) away. However, these CG, being organic, releases methane upon decomposition, which has a warming effect 84 times higher than that of carbon dioxide (Vaidyanathan, 2015). So what can we do to prevent such pollution?

A quick Google search would most probably direct us to compost CG as they contain potassium and nitrogen that are essential to plant growth. CG can also aerate soils and improve soil drainage, which can improve the roots ability to uptake water and nutrients. 

Image 1: Some benefits of using CG as fertilizer. Source: The Spruce, 2021

A quick guide to starting composting can be found here. The article in the link basically summarises three different ways to use CG as fertilizers. 

Adding CG:

1. directly to the soil

2. into a compost pile

3. into a compost system

Going with the compost pile method would be the safest and most economical route. However, if one decides to add CG directly to the soil, a note of caution would be to avoid adding excessive grounds. Excessive grounds can cake up and prevent water from infiltrating the soil, thereby dehydrating the plants instead of helping them to grow. One may also decide on a compost system, which generally involves purchasing decomposers, which personally can be a little expensive or repulsive.

While composting helps in recycling CG, some have advised against using CG as fertilizers as they can be acidic, and they contain caffeine, which may be detrimental to plant growth (Besemer, 2021). However, spent CG are almost pH neutral and according to trees.com, the caffeine content is less harmful to mature plants than seedlings. This suggests that with proper knowledge on the dos and don'ts, CG as fertilizers can be largely beneficial to our plants at home, and we can save money on fertilizers while reducing pollution.

Image 2: Plants with (left) and without (right) the use of CG fertilizer. Source: Sacha, 2018

Overall, before we start composting, it is best to read up on the good practices and plan out our composting methods. With the proper techniques and enough support for coffee composting, perhaps pollution levels can dip, even just by a little.

Ways to reduce coffee pollution: Animal feed

Repurposing the waste generated from coffee is nothing new (Donkoh et al., 1988). Owing to heightened sustainability efforts, repurposing coffee pulps has gain more attention in the recent years. One way is by incorporating them into animal feed.

Research are conducted to understand the inclusion of dehydrated coffee pulps (DCP) into animal feed. Jayeola et al. (2020) found promising results, whereby DCP have the potential to replace 20% of commercial feed for dairy cows and 15% for pigs without detrimetnal side effects to these animals. Bouafou et al. (n.d.)  echos similar findings for other animals such as poultry and fishes. However, Bouafou cautions against the overuse of DCP as the caffeine and tannine levels will be too high, causing indigestion, resulting in lower yield of animal products, and may be inpallitable to the animals. 

Additionally, DCP is relatively cheap to incorporate into the animals' diets, providing a low cost solution for farmers in developing countries to produce their animal products. Cost effective ways to incorporate DCP include directly adding the dried coffee pulps into the feed and fermenting the pulps into silage. 

Incorporating coffee pulps into animal feed thus seems to be a feasible approach to prevent pollution, as it is accessible to farmers of different income levels, and it prevents the pollutant from entering into the environment. Having said that, farmers who are incline to give the method a go should understand the mechanisms behind making their animal feed to prevent the unintentional consequences mentioned.