Carbon dioxide emissions from cement production have doubled in the last 20 years, according to emissions scientist Robbie Andrew of Norway’s Centre for International Climate and Environmental Research (CICERO).
Global emissions from making cement for buildings, roads, and other infrastructure reached almost 2.9 billion tonnes of carbon dioxide in 2021, accounting for more than 7% of global carbon emissions. Back in 2002, cement emissions only totaled 1.4 billion tonnes.
Driven by China, global cement emissions have more than tripled since 1992, and are currently expanding at a pace of 2.6% per year. According to the International Energy Agency, the increase is not only fueled by the production growth, but also by the carbon intensity which rose 9.3% from 2015 to 2020, going in the opposite direction at a time when all sectors are asked to clean up their operations.
Cement emissions have expanded faster than most other carbon sources, said Rob Jackson, a Stanford University climate scientist, adding that cement emissions did not decrease during the COVID-19 pandemic. “They did not expand as much, but they did not drop as much as oil, gas, and coal did.”
Unlike other key materials like steel, cement not only requires large amount of heat to produce, but the chemical process of producing cement itself creates a lot of carbon dioxide, making it difficult for the industry to decarbonize.
Steve Davis, an Earth system expert at the University of California remarked that on average, each individual on the earth consumes more than a kilogram of cement every day. Even though there are cleaner ways to create cement, it’s still complicated for the sector to cut emissions since it will require significant change in infrastructure and business practices. Instead, emissions from hard-to-abate sectors such as cement, steel, and aircraft will need to be offset by negative emissions elsewhere, according to IEA researchers.
Andrew estimates that China is critical since it produced more than half of the worlds cement emissions in 2021, with India a distant second at just 9%. The United States accounted for 2.5% of cement emissions, ranking fifth behind Vietnam and Turkey.