Society is in the process of moving away from fossil fuels towards renewable energy sources. But that is not enough. Society also needs to switch to more sustainable production and consumption patterns. A circular economy will play an important role here.
Material flows are mostly linear in society today. This can be clearly seen if we look at how society uses oil. Crude oil is pumped up, refined and mostly combusted as fuel that generates carbon dioxide emissions. This, in turn, contributes to climate changes and ocean acidification. Some of the oil is used to make different materials, such as plastic products for example. However, in the case of Sweden, only around 10 percent of plastics used is recycled. Most of it is sent for combustion to turn waste into energy instead, primarily for heat and electricity, but this also generates emissions of carbon dioxide.
A circular economy is being promoted as an alternative to this linear model. This means that materials and products are used in ways that enable the products to be re-used and the materials to be recycled. And in so doing, minimise the amount of waste. Substantial environmental benefits are often associated with this. For example, recycling 1 kg of plastic (instead of it going to combustion and new plastic being manufactured from oil) would cut emissions by several kilos of carbon dioxide. Recycling metals such as aluminium and steel can also save many kg of carbon dioxide emissions.
Reusing products is another example. When KTH neighbour IVL renovated their offices in Stockholm, they resolved to reuse furniture and interior design materials wherever possible. In so doing, they not only reduced the amount of waste by 12 tons and emissions of greenhouse gases by around 40 tons, but the final cost was cheaper.
A circular economy needs to be combined with the elimination of fossil fuels. If electric cars are to be sustainable, the batteries must be able to be recycled and vehicle materials recovered. If the steel industry is to become climate-neutral by 2045, neither the development of fossil fuel free production nor circular business models with increased recycling will be sufficient on their own, only by combining the two will this be a possibility.
A circular economy is not simply about recycling more, reusing more and using renewable materials. It also calls for new product designs, new business models, new product systems, new consumption patterns and new instruments of control that support a circular economy. KTH is pursuing research in all these areas, such as here, here and here.
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