Each year, the United States spends almost a trillion dollars attempting to combat metallic corrosion, an electrochemical reaction which occurs when metals oxidize and begin to rust. Now, a team of researchers led by the Ohio State University (OSU) has estimated how much corrosion is gradually worsening global carbon emissions.
Although previous research has already estimated the economic cost of corrosion to be about three to four percent of United States’ gross domestic product, this is the first study to quantify the environmental impact associated with steel corrosion.
Global steel production has increased steadily for decades and, since steel has poor resistance to corrosion, part of that demand is to replace steel from construction materials that have become corroded over time. According to the experts, reducing the amount of steel which needs to be replaced due to corrosion could have significant effects on the amount of greenhouse gases produced to make steel.
“Given society’s reliance on coal fuel, iron and steel production is one of the largest greenhouse gases emitters of any industry. But most of the costs associated with the industry actually stem from the energy that goes into creating steel, and that energy is lost as the steel reverts to rust, which is similar to its original form of iron ore,” explained study senior author Gerald Frankel, a professor of Materials Science and Engineering at OSU.
By using historical carbon dioxide intensity data in order to estimate CO2 levels per year starting from 1960, the scientists found that, in 2021, steel production accounted for 27 percent of the carbon emissions of the global manufacturing sector, and approximately 10.5 percent of the total carbon emissions worldwide, while corroded steel emissions accounted for about 1.6 to 3.4 percent of emissions.
Fortunately, due to regulations placed on the steel industry, technological advancements in the steel industry have resulted in a 61 percent reduction in energy consumption over the past half a century. Nonetheless, policy makers and industry officials should still act urgently to amend and coordinate international policy concerning steel production and corrosion management.
“Coordinated international strategies, as well as decreasing global steel demand, by using best practices for corrosion mitigation, could better improve global corrosion management strategies and drastically reduce the rise in greenhouse gas emissions we’re seeing due to repeatedly replacing corroded steel,” Frankel said.
If such actions are not undertaken soon, greenhouse emissions caused by the steel industry could spike to 27.5 percent of the global carbon emissions by as early as 2030, with corroded steel representing four to nine percent of that number. This could have dire impacts on the Earth’s climate.
“Global warming is a societal challenge that takes coordination of a lot of multidisciplinary approaches. Our work is bringing to light an issue that seems to have gone under the radar in terms of the importance of adding to the problem,” Frankel concluded.
The study is published in the journal npj Materials Degradation.
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