Study assesses climate cost of US manufacturing

Producing materials such as steel and plastics in the US causes $79bn a year in climate-related damage around the world, a study by engineers and economists has found.

The study assessed the climate costs of emissions using the Environmental Protection Agency’s Social Cost of Carbon standard
The study assessed the climate costs of emissions using the Environmental Protection Agency’s Social Cost of Carbon standard - AdobeStock

According to the team at the University of California, Davis, accounting for these costs in market prices could encourage progress toward climate-friendly alternatives. Their findings are detailed in Environmental Research Letters

“We wanted to look at the cost to society to produce these materials,” said Elisabeth Van Roijen, lead author and recent Ph.D. graduate from the UC Davis Department of Civil and Environmental Engineering.

Van Roijen, undergraduate researcher Paikea Colligan and postdoctoral researcher Seth Kane set out to calculate the missing climate costs for producing aluminium, iron and steel, brick, cement, lime, gypsum, asphalt, glass and plastics. 

They gathered data on the amounts of these materials produced in the US, the energy used to make them and the greenhouse gas emissions from the manufacturing process. They assessed the climate costs of emissions using the Environmental Protection Agency’s Social Cost of Carbon standard. This is an estimate of the costs of carbon dioxide emissions, such as preventing, mitigating and recovering from climate-related natural disasters. 

The team calculated that 370 million tons of these nine materials were manufactured in the US in 2018, resulting in 427 million tons of carbon dioxide emissions. This resulted in $79bn of climate costs that are not included in the market prices of these materials. 

Climate costs are affected by material demand. For example, manufacturing aluminium generates quite a lot of carbon dioxide per weight of product, while making the same amount of brick generates much less. But the tonnage of bricks produced every year is far higher than that of aluminium, so making bricks contributes more to climate costs overall than making aluminium. 

Steel and plastics have the highest overall contribution due to the very large demand for these materials.

In total, 42 per cent came from manufacturing processes, rather than energy use; making cement produces carbon dioxide because of the chemical reactions involved, in addition to any energy consumed. 

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According to the team, this is important because while climate costs of energy can be reduced by switching to renewable sources, process costs are fixed unless new processes or substitute materials are developed. 

“Alternative materials are a really important research area,” Van Roijen said in a statement. These could include supplements to partly replace cement in concrete and biomass-based plastics. 

Incorporating climate costs shows that the real cost of manufacturing these materials is much higher than current market prices. Adopting policies that reflect these costs can create incentives to develop new, climate-friendly processes and materials.

“When considering new technologies, such as biomass-based plastics, if we can account for the benefit of carbon storage in the material, we can make them more cost-effective in the market,” said Van Roijen. 

The manufacturing dataset will inform practical and policy work, Kane said. The same methods could also be replicated for other sectors of the economy.