Holcim has announced today that it has concluded the sale of its 75% stake of its Zambian business to Huaxin Cement. Meanwhile, in Tanzania last week, Huaxin Cement officially commissioned a cement grinding line at its Tanzanian Maweni Limestone plant. China produces about half the world’s cement and some its producers are expanding overseas as domestic growth dwindles. These actions and others place increased scrutiny on sustainability issues for Chinese cement producers. Readers therefore may be interested to note the publication last week of a list of the 100 largest Chinese corporate emitters of CO₂ in 2020.

The Chinese Cement Association (CCA) website carries some highlights on the work by from the cement sector’s perspective. China Venture Carbon and Caixin compiled the list of publicly listed companies using a mixture of freely available data such as sustainability reports, by adjusting public data or by making estimates. The companies covered released 4.42Bnt of CO₂ in 2020 or 45% of the Chinese total. The 15 cement firms in the top 100 were responsible for 893Mt of CO₂ or around 9% of the national total. This ratio is in keeping with the usual 5 – 10% share of global CO₂ emissions attributed to cement production.

Graph 1: Global gross CO₂ emissions by large cement companies in 2020. Source: China Venture Carbon/ Caixin, corporate sustainability reports. Note: Includes all reported direct and indirect emissions for all company business lines.

Many of the Chinese cement companies already release sustainability data each year so this data isn’t exactly new. Yet seeing it all in one place like this is illuminating. Unsurprisingly, on the cement side the ranking is a list of producers ordered roughly by production capacity. The world’s biggest cement producer CNBM is also the cement company that emits the most CO₂. It released 255Mt of CO₂ in 2020. If it were a country, for example, it would be around the 20th largest emitter in the world with a similar output to France or Thailand. In China CNBM is then followed by Anhui Conch, BBMG, Tangshan Jidong Cement and China Resources Cement (CRC).

Graph 1 above also includes the total gross CO₂ emissions for other large cement producers outside of China in 2020 for comparison. These figures are estimates compiled from company sustainability reports and they attempt to cover all direct and indirect emissions across all business lines not just cement. Similar to the Chinese list, generally, the less CO₂ a cement company emits on this graph the less cement it produces. It is also worth noting that 2020 was an unusual year given the outbreak of the coronavirus pandemic. Generally this reduced global manufacturing output but there was wide regional variation.

The other interesting point to note from the China Venture Carbon-Caixin project is that they re-ranked their list by carbon emission intensity, measured as emissions as a proportion of revenue. This totally changes the ordering. Where before the 15 cement companies were fairly evenly spaced out amongst power generators, coal producers and petrochemical companies, now all of them are in the top 50. As the CCA notes in its commentary, “The emission intensity of electricity and cement is much higher than that of other industries. The top 30 companies in terms of carbon emission intensity are almost all power and cement companies.” Whilst most of these companies are probably safe for the time being, given their size, what this might mean for smaller Chinese cement companies with high emission intensity in light of the Chinese government’s energy efficiency drives might be seen as worrying.

Promoting gross CO₂ emissions by cement producers is generally avoided by cement producers because it makes them look bad! It prompts an argument with the environmental lobby and doesn’t recognise the essential nature of cementitious building products to society. However, to their credit producers are publishing the data. The preferred metric for the non-Chinese multinationals is specific emissions per tonne of cement as this better shows the hard-work made to reduce emissions. However, this risks a credibility gap from the outside world, if specific emissions go down but total emissions keep rising each year. In the meantime though the more data the better from China and everywhere else.