Millionaire Bill Gates published a text on the blog Gate Notes, almost a decade ago, which caused data on cement consumption in China and the United States (USA) to become “viral”. In the article, the founder of Microsoft mentioned that China had used more cement in three years than the US had used in an entire century.
Now, a researcher from the University of Oxford, in the United Kingdom, decided to do the math and realized that the scenario is even more surprising: the Asian country needed only two years – and not three – to spend the equivalent of the cement used in the USA when over 100 years.
“I’m skeptical of most stats going viral, so I wanted to double-check these numbers and do mine and calculations. This value [referido por Gates] is still close to being true, except for the fact that China consumes as much cement every two years as the US did during the entire 20th century”, he writes the scientist Hannah Ritchie on the page that maintains the platform substack.
The comparison between China and the United States is mentioned on Bill Gates’ blog about the book Making the Modern World: Materials and Dematerialization, by historian Vaclav Smil. After quoting Gates, the comparison motivated different news in reference media such as magazine forbesthe British newspaper The Independent or the american washington post.
The researcher used data published by the US Geological Survey, the US entity that monitors seismic and geological data, to account for the manufacture and use of cement from 1900 to 1999 in the US. During this period, 4.2 billion tons of cement were produced and 4.4 billion tons were consumed.
China, in turn, produced 2.4 billion tons in 2020 and 2.5 billion tons in 2021, totaling 4.9 billion in just two years.
“This is production (not consumption), but based on the trade numbers I could find, China exports very little cement – only around 5 million tonnes. This means that production and consumption are basically the same”, says Ritchie, who, in addition to being a researcher at Oxford, works as a sub-editor of the publication Our World in Data.
China dominates the sector
The researcher adds that the data show that, for more than a decade, China has been calling the shots in this sector. In 2014, for example, the country manufactured 60% of the world’s cement. And she underlines that these numbers are not only socio-economically relevant – industrialization will have allowed for an improvement in the quality of life and the decline of poverty –, but also an environmental one.
After water, cement is the Most used substance on Earth. This despite the fact that, unlike water, it does not occur naturally in nature. Around 8% of global CO2 emissions are linked to cement production and trade, according to data from the Intergovernmental Panel on Climate change (IPCC).
Indeed, cement is one of the biggest challenges in the fight against the climate crisis. In cement plants, it is not enough to electrify processes or bet on renewable energy for more environmentally friendly processes. Most of the emissions that the sector generates are not linked to fossil fuelsbut to crucial chemical processes during the manufacture of the product.
To obtain clinker – the key ingredient in cement – it is necessary to calcine limestone and, in smaller quantities, clay and elements such as aluminum and iron. This calcination is a process that involves very high temperatures (something close to 1500 degrees Celsius) and promotes the release of carbon dioxide into the atmosphere. It is estimated that around half of the sector’s emissions are linked precisely to these chemical processes that take place in cement plants.
“Unsurprisingly, given the amount of cement it produces, China dominates global cement emissions. It emits around 852 million tonnes, which is nearly double South Africa’s total fossil emissions. The problem with cement is that it’s an industry that we can’t just decarbonize by switching to renewable or nuclear energy. We need innovations to eliminate the production of CO2 from the direct process itself”, says the researcher Hannah Ritchie in your page.