Climate impact of circularity

When can recycling reduce emissions?

The key goal of circularity is to optimise the way we use materials in our economies. Rather than being an end in itself, it allows us to reach more sustainable ways of producing and consuming products and materials.

‘’A circular economy aims to maximise the added value of products and services in the economic value chain, both to minimise residual waste and to ensure that resources can stay longer within the economy. ‘’ [i]

Using materials more efficiently is complementary to direct reduction of emissions in the economy. In other words, circularity can help societies in maximizing the use of the resources extracted and produced, and give a ‘bigger bang’ for ‘a buck’ of the materials produced. Circularity has an important role to play in slowing down the growth of primary production by enabling societies to use materials multiple times and retain the value of products that are already being produced and used in the economy.

Separating Waste

A good example of circularity is the recycling of simple materials such as metals or glass, which can be sorted after use and recycled back into production of the same products. A glass bottle can, in theory, be infinitely recycled and not lose any of its physical properties that make it suitable for its use. Due to this consistency in quality and the cost-effectiveness of glass recycling, an old glass bottle can actually replace a new glass bottle on the market. The purer the material, the easier it will be sorted, recycled and used for its original purpose. While glass and metals, provided that they’re separated well from other materials, can be recycled multiple times, some materials such as plastics degrade and change their physical properties already after one cycle, making circularity difficult to achieve.  

The main obstacle to material circularity is the complexity of the products and the economy.

Manufactured items with many components and materials, particularly electrical and electronic equipment, are becoming more complex and are not designed to accommodate perfect separation of materials after their disposal.

Cycling materials in a complex economy is not a simple task. For instance, there are 7 major types of plastics alone, each of which is classified into more subtypes and combined with a different set of chemicals for a certain product. This means that each time a plastic product is recycled, it will change its chemical composition and is therefore not likely to be used for the same purpose, commonly known as downcycling. The issues that comes with such complexity of products mean that circularity cannot always be used to replace the primary (virgin) production of materials. In addition, it often means that material losses are incurred along the way and additional energy is brought into the system [ii]. 

‘’Recovery and recycling of materials that have been dispersed through pollution, waste and end-of-life product disposal require energy and resources, which increase in a nonlinear manner as the percentage of recycled material rises (owing to the second law of thermodynamics: entropy causing dispersion). Recovery can never be 100% [iii]. The level of recycling that is appropriate may differ between materials.’’ [i].

The reality of circularity is far from theory and products often cannot be in an infinitely closed loop. The deviations from this perfect loop are majorly due to the fact that not all materials can be collected and recycled in the current waste management system. The process of collection and separation is inherently leaky and the collection, sorting and recycling processes require the additional use of energy and in some cases, additional materials. Beyond all this, the recycled products may not be up to standard, failing to replace the product they were derived from. Despite the lack of a perfect loop, circularity can still have positive climate impacts.

How can circularity contribute to climate change?

The extent to which the benefits of circular economy measures can be quantified is still not completely clear, as processes such as recycling does not automatically translate to overall reduction in CO2 emissions. Climate benefits of circularity measures hinge on a multitude of factors, overall recycling rates, emissions in processing and end of life treatment and energy requirement for collection and sorting. Simplifications in these models inevitably affect the validity of the outcomes [i].   

Ultimately it is the increasing concentrations of CO2 in the atmosphere that drive the changing climate. Accounting for these emissions and hence reflecting the physical changes to the system is key to transparent and robust climate action.



Circular economy measures may contribute to climate action based on two assumptions:

   1. Slowing the growth of primary production of materials  

Primary production of materials brings with it emissions due to the extraction of materials. Global resource extraction has tripled since 1970 and by 2060, global material use could double from current levels to 190 billion tonnes [iv]. Slowing down this growth is vital to climate action as this would lead to an increase in GHG emissions by 43%.


Circular economy measures contribute to climate action as recycled products potentially displace virgin products, displacing often more carbon intensive primary production. This would help in climate action by reducing emissions due to the extraction of raw materials. Circularity measures may only affect the rate of primary production, slowing its growth, but will never fully halt it.

   2. Permanent storage of carbon in the material

Carbon can be kept away from the atmosphere if the products that contain it can persist in a circular loop. This would then be permanent storage if the product stays in a ‘perfect’ circular loop. Thus, for circularity to be a permanent carbon store, a 100% collection rate is necessary with zero leakage or losses. In addition, the cycle must be maintained in perpetuity for this assumption to hold. From a climate perspective, circularity can reduce emissions in this way only when the cycle is perpetual, keeping carbon permanently locked away from the atmosphere.

Who takes credit when circularity reduces emissions?

Circularity measures involve multiple stakeholders across the value chain; producers, consumers and recyclers all have a role to play. Incentivising such measures needs to yield benefits to these stakeholders, and who takes credit for positive environmental impacts requires clarity. Lack of such clarity would allow greenwashing and exaggerated claims, for example, both virgin plastic producers and recyclers claiming emissions reduction for the same circularity measure. Allocation of emissions reductions credits needs to avoid such double counting.

Increasing circularity measures comes with significant costs and technological barriers that need to be addressed in policies. Products (e.g., plastics) are sometimes claimed to be decarbonised in the future via reuse and recycling further down the value chain, but their producers have no incentive to ensure that the products are reuse or recycled at the end of their life.

  • That primary/virgin products will be decarbonised with circularity measures require an obligation for the producer to have their products recycled and reused.

  • Plastic product producers can only claim benefit for circularity if they ensure their product is recycled at the end-of-life, and retain liability for emissions on disposal (e.g., incineration).  

  • Alternatively, primary producers cannot make any climate claims as a result of circularity. Climate benefits that may arise go solely to the industry that is performing the recycling/reuse. 

Targeting barriers to for circularity

Three major components form the base of a truly circular value chain; products designed to be recycled, effective collection and sorting and adequate recycling capacity. Barriers to circularity can be found within these components; primary producers do not have the incentive to develop such a circular system. For example, production and conversion of fossil based plastic products accounts for 91% of GHG emissions, the remaining 9% due to end of life handling [v], usually resulting in carbon being released into the atmosphere. Despite this share, the responsibility for building a circular economy lies with end of life stakeholders. As a result the current structure does not place any responsibility on plastic producers to create more recyclable products.     

Clear allocation of responsibilities is needed

A basic tenet of the circular economy is that the resource flow systems that underpin design models need to be re-engineered. There is no point designing a product for disassembly if take-back mechanisms are lacking to recover component parts effectively.

New waste management systems are needed

The importance of the role of the waste management regime - a critical issue is how to set the regulations and criteria for determining when recycled waste ceases to be treated as waste and becomes a resource, raw material or product

Key measures and enablers needed

Overall, several key policy measures are needed to ensure a robust legislative framework for circularity:

1. Accounting for all emissions and ‘leaks’ of CO2 to the atmosphere, regardless of circularity measures.

2. Identifying false circularity and related carbon neutrality claims.

3. Overcoming sector-specific challenges and focusing both on circularity and emission reductions in primary production. Circularity measures are complementary to emission reductions in primary production of materials and their contribution needs to be based on realistic assumptions of what happens to materials in the waste management sector.

4.  Clearly allocating responsibility and incentives for circularity measures.

6. Durability and long lifetimes of products need to be rewarded to encourage products with longer lifecycles 

7. The difference between different circularity measures needs to be recognised. For example, reduction and reuse should be clearly preferred to recycling and downcycling.


[i] EASAC 2015. Available at:

[ii] Castro, M.B.G., J.A.M. Remmerswaal, J.C. Brezet, M.A. Reuter. 2007. Exergy losses during recycling and the resource efficiency of product systems, Resources, Conservation and Recycling 52 (2): 219-233. Available at:

[iii] Faber, Ronald J., Thomas C. O'Guinn, and Raymond Krych. "Compulsive consumption." ACR North American Advances (1987). Available at:

[iv] UNEP 2019, GRO. Available at:

[v] Zheng, Jiajia & Suh, Sangwon. (2019). Strategies to reduce the global carbon footprint of plastics. Nature Climate Change. 10.1038/s41558-019-0459-z.