Engineers must find ways to use less material when designing buildings and products in order to cut carbon emissions, according to a new report.
Developing low-carbon energy supplies and increasing recycling will not be enough if the world wants to meet its climate-change targets while maintaining economic growth and so materials must be used more efficiently, a group of researchers has said in an article produced for the Royal Society.
This could be done by creating products for longer and more intense use, by reducing waste, by reusing more components or through lightweight design, said the report. But policy changes will also be needed, it added, because the economy currently encourages inefficient material use.
‘With a growing population and increasing wealth, demand for material extraction and processing is likely to double in the next 40 years,’ said the article, written by researchers from Cambridge and Utrecht universities and the Massachusetts Institute of Technology (MIT).
‘The environmental impacts of the required processing will become critical. In particular, the industrial sector drives nearly one third of global energy demand, with most of this energy used to produce bulk materials.
‘However, there will be significant limits to future improvements in process efficiency, because energy costs have already driven key processes near to their technical limits. Therefore, a key component of mankind’s response to global warming must be to produce less new material.’
The report noted that there may be conflicts between the different solutions proposed for increasing material efficiency. For example, making a product more lightweight may not help increase its lifespan.
The writers also argued that the goal must be physical efficiency rather than economic efficiency — in other words, reducing the overall use of materials while maintaining levels of service, rather than making individual products cheaper in a way that means more of them are manufactured and total material use goes up.
Solutions would therefore have to take into account economic factors such as the relatively low cost of materials compared with labour, which means it can cost more to employ someone to build a product in a more innovative way with less material than it is to produce a simpler design with more material.
Political changes would also be needed to make sure material efficiency didn’t destroy jobs or prevent economic growth. The researchers argued that adjusting existing policies, such as building regulations or vehicle standards, could be more effective than the very difficult tasks of setting up an international carbon pricing system or taxing materials instead of labour.
The report, entitled ‘Material efficiency: providing material services with less material production’, is the introduction to the latest issue of Philosophical Transactions of the Royal Society A, which features a series of articles on the topic of material efficiency.