CO2 Emissions From Global Cement Production Have Doubled In Past 20 Years
Heat trapping carbon dioxide emissions from making cement, a less talked about but major source of carbon pollution, have doubled in the last 20 years, new global data shows. In 2021, worldwide emissions from making cement for buildings, roads and other infrastructure hit nearly 2.9 billion tons (2.6 billion metric tons) of carbon dioxide, which is more than 7% of the global carbon emissions, according to emissions scientist Robbie Andrew of Norway’s CICERO Center for International Climate Research and the Global Carbon Project. Twenty years ago, in 2002, cement emissions were some 1.4 billion tons (1.2 billion metric tons) of carbon dioxide.
Driven by China, global cement emissions globally have more than tripled since 1992, recently growing at a rate of 2.6% a year. It’s not just that more cement is being made and used. At a time when all industries are supposed to be cleaning up their processes, cement has actually been going in the opposite direction. The carbon intensity of cement — how much pollution is emitted per ton — has increased 9.3% from 2015 to 2020, primarily because of China, according to the International Energy Agency.
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China is not just making and using more cement, but the carbon intensity has been going up a lot lately, IEA’s Voss said. That’s because earlier in its development, China was using cheaper, weaker low-clinker cement and buildings and bridges were collapsing, so now the Chinese government is mandating stronger cement, Norway’s Andrew said. That’s a reasonable conservatism that slows efforts at making greener cement, Davis said. People are not eager to try untested cement recipes because “these are the structural materials of our society,” he said.
For example, Portland limestone cement has 10% less emissions but customers are so worried about strength they often say they are only willing to use it if they use 10% more. Different cement uses have specific needs, such as strength versus longevity but users often just want the strongest and most durable when they don’t need it and this causes unnecessary emissions, Bohan said. And while people talk about curtailing flying, global aviation emissions are less than half of that coming from concrete, according to Global Carbon Project. There’s “flight shaming” among scientists and activists, but no building shaming, Davis said.
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https://apnews.com/article/climate-science-china-pollution-3d97642acbb07fca7540edca38448266
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