Breaking It Down: Aerobic vs. Anaerobic Composting

Hearing the term aerobic might make you think of a cardio session at the gym, but it also applies to the two main methods of composting.

Aerobic refers to the breakdown – known as digestion –  of organic materials with oxygen, and anaerobic is without oxygen. These terms usually refer to large-scale composting at facilities, though smaller, backyard composting can be considered aerobic.

In Canada, aerobic digestion is used in most cities and communities that collect compost; it’s considered the more traditional, common method. With this, at a facility, compostable material is placed into a large pile and left for several months until it breaks down into humus, a substance used to condition soil. This is similar to at-home composting, where a pile of soil, food scraps, and some types of paper is put together and turned regularly until it breaks down.

With anaerobic digestion, organic matter is kept in an oxygen-free environment, and when it starts to digest, methane is produced, which can then be used for energy. The City of Toronto, Canada’s largest municipality with a compost collection program, currently uses anaerobic digestion.

There’s a lot of promise in the anaerobic method, as it can turn composted material into a new fuel source with wide-ranging applications. In fact, the City of Toronto has announced plans to capture the “biogas” (methane) from green bin waste and combine it with natural gas to power some homes and city-owned vehicles.

With this said, it’s important to understand that if the methane from anaerobic digestion is not captured or properly used, it can be problematic, as some of it may release freely into the environment. This is actually why composting is so important to begin with, because when food scraps are disposed of in normal garbage – not the ideal environment for digestion – they release methane, and their usefulness is squandered.

Both aerobic and anaerobic composting have their benefits, drawbacks, and useful applications. It’s not necessarily a matter of which is better, but rather, about aiming for higher diversion rates and better management of compost overall. This goes for both consumer engagement, and improved design of compostable products.

This need was seen in an examination of Toronto’s Disco Road compost facility, which processes up to 40% of the city’s green bin waste. While that number is pretty high, there’s still a sorting process that removes items said to be compostable, but aren’t, such as pieces of diapers, napkins, and cutlery. These things unfortunately end up in landfill, and we know that across Canada and elsewhere, diversion rates with compost are not as high as they could be.

To achieve the potential of both aerobic and anaerobic digestion methods, we need to improve the actual compostability of products, and continue to divert waste from landfill. Every food scrap and compostable item can be used for energy, or for our soil to grow more food – it just has to get there first.

One wooden domino block stop falling ones on white background, panorama

Systems Thinking  

In discussing climate change and other prominent issues, we often hear about ‘systems’, such as the frequent mention of “systemic problems”. This is tied to a concept called ‘systems thinking’, and it’s an important ideological framework for understanding the circular economy. 

What is systems thinking? 

The Ellen MacArthur Foundation, a circular economy advocacy group, defines systems thinking as: “The ability to understand how the parts of a system interact to produce the behaviour of the whole.” The Foundation references systems expert Donella Meadows, who describes it as a “way of thinking that gives us the freedom to identify root causes of problems and see new opportunities.” 

Systems thinking challenges us to look at the whole picture and understand how things are interconnected. It relates to the economy – and subsequently, the circular economy – in that it identifies how our current systems are grounded in linear thinking. Currently, our economy is based on resource extraction and the creation of waste and pollution. It moves in a straight line, without thorough consideration of how to manage and offset issues that arise. The circular economy seeks to overhaul this linear structure, and applies systems thinking by working from an understanding of larger problems, rather than focusing on just one piece. 

The Ellen MacArthur Foundation uses the example of ocean plastics to illustrate this. Plastic pollution in our oceans is a major global issue that relates to a variety of systems: overreliance on plastic, poor consumer education and awareness, lack of regulation, and so on. By seeing all the systems at play and using systems thinking, we can affect change by providing innovative solutions that address each part.  

Technical approach  

In order to facilitate systems thinking, there are a number of tools. The Circular Economy Practitioner Guide identifies a few of the most common ones as: 

  • Behaviour over time – This refers to trends in human behaviour over a certain time frame, as influenced by internal and external factors 
  • Policy structure – The political environment as it relates to a specific system or systems, and how it impacts decisions of individuals and groups 
  • Structure-behaviour relationships – This can be seen as a blend of the two above tools, looking at how behaviour changes in response to or within certain structures 

Many of these tools examine human behaviour and the impact of systems on people, and vice versa. Systems thinking itself requires a mindset shift for many, as our culture and economy has been so pervasively linear for so long. In a paper for Environmental Science and Pollution Research, the authors discuss this potential, stating that a systems thinking approach, “can build up the capabilities required to identify and understand persistent linear trends and, in turn, support forward-thinking and time investment in enabling sustainable transitions.”   

Overall, systems thinking within the circular economy helps us better understand where we are and why, in order to move toward a more sustainable future.

3D illustration of the cycle of manufacturing

Extended Producer Responsibility 

In our current linear economy, more waste is generated than we can handle. With the pace of resource extraction and product manufacturing, we have a seemingly endless stream of waste and pollution that continues to pile up in facilities and the environment. Although many cities and towns have their own forms of waste management, the idea of Extended Producer Responsibility (EPR) has been brought forth as a way to ensure producers shoulder more of the burden for waste management.  

The government of British Columbia defines EPR as “an approach to recycling that requires producers, such as manufacturers, distributors, and retailers to take responsibility for the life cycle of the products they sell.” This may be with collection, (curbside or through collection depots), or recycling of the actual packaging and products collected. Although EPR is a relatively newer concept, the BC government notes that producers have already started to employ it, and have in some cases formed groups that operate recycling programs on their behalf. 

Of course, EPR isn’t just taking place in BC; the Organisation for Economic Co-operation and Development (OECD) has also identified the benefits of the concept, defining it as  “a policy approach under which producers are given a significant responsibility – financial and/or physical – for the treatment or disposal of post-consumer products.” The OECD also describes EPR as something that can be implemented as formal policy, since it has the potential to “provide incentives to prevent wastes at the source, promote product design for the environment and support the achievement of public recycling and materials management goals.” 

The government of Canada has identified EPR as a goal within efforts to combat climate change, and it may continue to grow in popularity as a policy objective. In our article on the controversies with plastics recycling, we pointed out how the concept of responsibility is hotly debated. Many believe those who produce plastic products should take on more when it comes to not just recycling, but improving consumer education by providing accurate information about the recyclability of a product. Not only does EPR target this desire, but it can also encourage producers to better design products to either make them easier to recycle, or even more durable or compostable. 

Of course, EPR goes beyond plastics; every industry has the potential to benefit from taking on more awareness and responsibility for the ultimate life cycle of their products. EPR is a concept that aligns with the circular economy, as it asks producers to innovate and introduce circular strategies into their products, supply chains, and overall impact on consumers and the environment. 

On a white damaged wood board, wooden word cubes are arranged in

Life Cycle Assessment

Life cycle assessment, in short LCA, is a term we use often at 5REDO, and an important part of what we do in our consulting process. While the term seems self explanatory, a life cycle assessment is multifaceted, and its components can shift to address specific cases and situations. It’s a crucial step on the path to the circular economy, as it allows us to see and understand how to better use everyday products and materials.

What does ‘life cycle’ mean?
Just like people, plants, and animals, the products we use every day have a life span, even when we get rid of or no longer want them. A plastic fork, for example, may be used for five minutes, but remain in a landfill for up to 500 years. That’s a long time for a small, throwaway product.

The life cycle of a product means how long it will either take to break down in a landfill, composting center, or how many times it can be recycled or reused in different ways, sometimes after being broken down (different pieces of a product may have varying life cycles).

You may be familiar with the term “cradle to grave”, a popular phrase corporations use to describe the life of a product. A life cycle assessment in relation to the circular economy shifts this idea to “cradle to cradle”, meaning that the goal is to find a way to reuse, remanufacture, or reduce waste and give products new life.

What is a life cycle assessment?
A life cycle assessment is a method used to determine how much value is in a product, by finding out how long it’s typically used for (either by individuals or businesses, or both), if it can be recycled or reused, and how. At 5REDO, in line with circular economy principles, the goal is to both extend the life cycle of products and materials, and ensure everything used in a supply chain has the longest life cycle possible.

An LCA may look different depending on who is conducting it, and for what product or business. In general, there are four broad steps to an LCA, including:

  • Goal and scope definition
  • Inventory analysis
  • Impact assessment
  • Interpretation

Again, these stages may look different depending on the business. One of the most crucial pieces is the impact assessment, which is a breakdown of the current life cycle of an item, and the larger impact that has on the environment. Once the LCA is complete, we can also see how that impact will change when substituted with a more sustainable solution.

When should an LCA be performed?
Usually, an LCA is part of the larger process of analyzing and shifting a product or business to being more sustainable and environmentally responsible. It’s an important measurement tool, and the insights garnered from an LCA can help in the decision making process for businesses and consultants alike. At 5REDO, we are experienced in conducting LCAs for a variety of products and components in manufacturing.

Mountain road between Sarajevo and Tuzla

The 5Rs

Built into our firm’s name, the ‘5R’s — refuse, reduce, reuse, recycle, and remanufacture — are the pillars of the work we do. The very definition of 5REDO means helping businesses adopt the 5Rs; essential ingredients in the circular economy.

The original three
You may be familiar with the commonly known ‘three Rs’: reduce, reuse, recycle. Taken together, it’s a catch-phrase that dates back to the 1990s, when environmental movements began to call for recycling efforts in earnest. At the time, the impacts of human-caused climate change were only starting to become known on a wider level, and environmentally conscious efforts were slowly being introduced in government policies and business practices.

The first three Rs are important, and they’re still part of the broader 5R definition. However, as the climate crisis has become more urgent, environmental activists and innovators have agreed that reducing, reusing and recycling simply doesn’t cover the range of activities needed to combat climate change. From there, the broader definition evolved.

The original three
The 5Rs include: refuse, reduce, reuse, recycle, and remanufacture (some say ‘repurpose’ instead of reuse, though the idea is the same). The two additions are refuse and remanufacture; and it’s not just the addition of these two concepts that’s important, but the order.

Nowadays, we start with refuse because, put simply, the best approach to cutting down waste in all sectors is to not generate it in the first place. Refuse can be interpreted broadly, from opting out of purchasing or using wasteful items like plastic cutlery, or rejecting the pressures of our over-consuming culture by not buying things you don’t really need, like trendy clothing or new furniture. For companies, key decision-makers can refuse to use wasteful materials or practices, opting instead for sustainable methods.

Although ‘reuse’ seems to encompass the idea of repurposing products, remanufacture is a more specific, innovative concept. It calls on businesses and innovators to find a way to extend the life of their products and materials by bringing them back into the supply chain, emulating the circular economy.

For example, pulling fibers from used tires to help create new materials, or finding a way to break down components of items that can be reused in different parts of production. At 5REDO, finding opportunities for remanufacturing is a crucial part of what we do, as the circular economy demands that we make supply chains more regenerative and sustainable.

‘Reuse’ is simple and important; that plastic container we might normally throw away can be turned into a container to grow vegetable seedlings. ‘Remanufacture’, however, asks us to put our brightest ideas forward, and reimagine how we work with materials across all industries.

With the climate crisis more urgent than ever, the 5Rs are the way of the future. Taken together, they encourage individuals, companies, and everyone involved in environmental efforts to adopt more sustainable ways of living.


The Circular Economy

The circular economy is the foundation of everything we do at 5REDO. Our firm is built around this principle, and our core goal is to help move businesses, organizations, and our world toward it. It’s important not only for our clients and partners to understand this concept, but we believe everyone could benefit from learning about the circular economy.

What is the circular economy?

“What will it take to transform our throwaway economy into one where waste is eliminated, resources are circulated, and nature is regenerated?”

This is a question posed by The Ellen MacArthur Foundation, a group that works to accelerate the transition to a circular economy. It captures the essence of the concept on a broad level: to change the way things currently work, and create something better.

To understand the circular economy, we first need to grasp the structure of the current one, which still dictates the majority of businesses and production cycles around the world. The very notion of ‘circular’ indicates regeneration; something that sustains and replenishes, where each piece is connected. The opposite of this would be something linear: a cycle that starts at one point and ends at another. This is the basis on which our economy since the Industrial Age has been formed: an item is produced, used, and thrown away, either becoming garbage, or in some cases recycled or composted (but often not entirely). In any case, waste is generated to some extent. This is commonly referred to as the take-make-dispose system, and it defines many current production and supply chains.

An economy that is circular, then, is based on a sustainable system that prioritizes extending the value and life cycle of products, and reducing or refusing waste. In a circular economy, we produce with value, intent, and innovation, and make decisions based on protecting the environment.

What does the circular economy look like?
There are already many innovators, business owners, and everyday people across the globe incorporating principles of the circular economy into their lives. At 5REDO, we focus on helping businesses adopt and shift to circular economy principles, but you don’t have to be a corporation to take on the values associated with it.

By reusing, repurposing, or extending the life of everyday items you own, you’re participating in the circular economy. Repairing clothing or tools, using scrap materials to build furniture, or reducing the amount of single-use items you own are all examples of how to incorporate the circular economy into your everyday life.

An example of the circular economy on a larger scale looks like restructuring the types of materials used in production, and extending this across the whole supply chain. For example, a company that makes tires may look at using recycled or upcycled materials for new tires, and extending the life of used tires by repurposing the components for construction of new materials (our firm conducted a study about this, showing how it’s been effective in Europe and could translate to the North American market).

What are the impacts of a circular economy?
Transitioning to a circular economy does not have to equal loss of jobs or a dip in economic productivity. Rather, it prioritizes protecting our planet while also fostering innovation and encouraging a more global mindset, where resources are shared and we put more care and thought into our everyday practices.

Canada has explicitly identified the circular economy as a priority, and each day, innovators are finding solutions to outdated, environmentally harmful methods across many industries. The circular economy is the way of the future.

Resources & further reading