Companies must reduce the amount of materials used to manufacture products and construct buildings to cut carbon emissions in line with climate change goals, say academics
With one-sixth of the world’s energy used to manufacture just five key materials – aluminium, steel, cement, plastic and paper – producing fewer new materials will be crucial in lowering carbon emissions sufficiently to halt global warming, according to researchers from Cambridge University and MIT.
In a paper published by the Royal Society, the academics conclude that in order to reduce global carbon emissions to limit temperature rises to 2°C in 2050, products need to use less materials.
Optimising product designs for material efficiency rather than cost saves around one-third of the materials, according to the paper, saving energy and reducing carbon emissions.
More efficient design should be adopted alongside increased recycling of resources, substitution of energy-intensive materials and a shift towards renewable energy supplies, say the authors. However, they point out that current business models mean that it is cheaper to overbuy materials than to invest in designing more efficient products.
“We’re caught in an economic trap in that labour is expensive and that materials are very cheap,” explains the report’s co-author Julian Alwood, from Cambridge University’s engineering department. “Unfortunately, it’s completely rational at the moment to use more material if we can use less labour. So in designing buildings it’s cheaper to approximate and use more material, than to pay for the design time to make the building exactly conform to Eurocode standards.”
As well as designing products in a way that uses fewer materials initially, companies should also design products with longer life cycles and to enable individual components to be replaced or reused. The academics cite research suggesting that around 30% of components in steel and aluminium products could be reused at the end of the product’s life.
Manufacturers could also do more to improve waste in production, says the paper, particularly those working with sheet metal. Half of all liquid metal becomes scrap en route to the final product, it says, and while the majority of the waste is recycled, the process is energy-intensive, expelling carbon emissions that could have been avoided.
Furthermore, instead of being melted down, manufacturing scrap could be used as the source for other smaller blanks, it suggests.
“The strategies of material efficiency – delivering material services with less overall material production – must form part of the portfolio of mitigation options for industrial CO2 emissions,” states the report.
The academic paper followed a report from the Ellen MacArthur Foundation, which concluded that the adoption of a circular economy approach in the consumer goods sector could generate savings of $700 billion.
The research found that increasing rates of reuse and recycling in the textiles sector could save more than $70 billion and that switching to re-usable glass bottles could reduce drinks manufacturers’ packaging costs by 20%.
