Building new homes is the biggest chunk of cement-related carbon emissions in China, shows work led by Dr. Yuli Shan of the Tyndall Centre for Climate Change Research and newly published in the Journal of Industrial Economy.
Globally, China produces the most cement and therefore the most cement-related CO2 emissions. China used more cement in 2011-2013than the US did in the entire 20thcentury.
Residential buildings account for 40% of cement emissions followed by infrastructures at 25% and factories at 10%. This is the first study to look at cement demands of different building types in China. The cement industry is responsible for 15% of China’s total GHG emissions.
The cement industry contributes to 8% of total global carbon emissions, more than the emissions of any other country other than the US and China. If cement manufacture was a country, it would be the third highest emitter after China and the US. Cement emissions will need to fall at least 16% by 2030 in order to meet the Paris Agreement goal.
Cement is the basic ingredient of concrete; it is durable and cheap. More than half of cement related emissions come from making clinker, a major cement component that acts as a binder. The process involves the calcination of limestone to produce lime, leading to the release of waste CO2. Cement production is also very energy intensive.
Key strategies to cut carbon emissions in cement productioninclude improving energy and cement-mix efficiency, switching to lower-carbon fuels, reducing the clinker-to-cement ratio and advancing process and technology innovations.
China is the largest producer of cement, accounting for close to 60% of global production, followed by India at 7%. Cement production is likely to decline in China in the long term, but increases are anticipated in India and other developing Asian and African countries.
“The cement industry is the major source of emissions in China, and more attention should be paid to the cement industry, especially as new buildings are a consequence of economic growth,” said Shan.
China has proposed policies to reduce energy consumption and CO2 emissions from the cement industry. It aims to achieve a 30% reduction of air pollutant emissions of the cement industry in 2020 compared to the 2015 level.
“Accurate accounts of the cement-related emissions and understanding the driving forces of the changes in emissions is valuable, and is significant for policymaking,” Shan said.
Shan’s work is the first to shed light on emissions specific to buildings in China, giving national policymakers a new set of data for better informing emissions analysis.
Read Shan’s paper here.