Study finds Japanese buildings absorb 14% of cement production’s carbon footprint

A crew of Japanese researchers has found that Japan’s concrete constructions—together with buildings and infrastructure—soak up and retailer about 14% of the carbon dioxide (CO₂) emissions generated throughout cement manufacturing.

This analysis offers important information to offset CO₂ emissions from cement manufacturing, a major contributor to international carbon emissions at roughly 8%. The examine is published within the Journal of Cleaner Manufacturing.

With the rising urgency of local weather change, scientists are focusing not solely on decreasing CO₂ emissions but additionally on efficient strategies of capturing and storing atmospheric CO₂ to mitigate international warming.

Concrete naturally absorbs CO₂ all through its lifetime via a course of known as carbonation, also called CO₂ uptake. Whereas this course of can contribute to the corrosion of reinforcing metal bars in concrete structuresit additionally permits concrete constructions to perform as carbon sinks.

Professor Ippei Maruyama of the College of Tokyo, Professor Hiroki Tanikawa of Nagoya College, and their colleagues carried out a complete materials stock-flow evaluation of Japan’s concrete from 1870 (when Japan started producing cement) to 2070.

Materials stock-flow evaluation is an accounting technique that tracks how supplies enter a system (flows), accumulate inside it over time (shares), and finally exit via disposal, recycling, or different means, permitting us to grasp the entire lifecycle of sources in our economic system and atmosphere. Their evaluation aimed to estimate the CO₂ uptake of concrete constructions on a nationwide scale.

The researchers used statistical information to estimate annual home cement manufacturing, the lifespan of varied concrete constructions, and their disposal strategies. They quantified the full quantity of CO₂ captured and saved based mostly on the floor space of concrete constructions all through Japan.

To precisely calculate the full floor space, the researchers included information on the surface-to-volume ratio of various kinds of concrete constructions that replicate Japanese constructing design requirements. As an earthquake-prone nation, Japan has particular earthquake-resistant requirements that wanted to be factored into these calculations.

The examine additionally accounted for native environmental situations, ending supplies, and what occurs to concrete after demolition. “The main objective of our analysis is to improve CO₂ uptake quantification by considering time-series changes and local-specific factors,” Professor Maruyama defined.

The outcomes revealed that the cumulative CO₂ uptake from 1870 to 2020 was estimated at 137.1 million tons, representing 7.5% of the cumulative CO₂ emissions from calcination throughout cement manufacturing. In 2020 alone, annual CO₂ uptake reached 2.6 million tons, accounting for 13.9% of CO₂ emissions from cement calcination that 12 months.

Projections recommend that annual CO₂ uptake will improve barely through the 2020s earlier than dropping to 2.3-2.4 million tons by 2070. “These results could easily be reversed, depending on waste management methods and other conditions,” the researchers famous.

Professor Tanikawa concludes, “Research on the detailed evaluation of the full CO₂ absorbed by concrete constructions on the nationwide scale are of nice significance. Concrete buildings and infrastructure carry on absorbing CO₂ so long as they’re uncovered to the air.

“Concrete structures act as carbon sinks, even though they absorb less CO₂ than forests. With this in mind, we should take good care of buildings and infrastructure around us so that they have a long service life.”