How to Reduce Emissions from Concrete Production

As the global population continues to swell and economies prosper, concrete is more in-demand than ever before. Unfortunately, its production is not without adverse effects on the environment, in both a local and universal sense. At present, concrete production accounts for around 8% of all greenhouse gas (GHG) emissions around the world.

While industry experts are examining methods of curbing that footprint, some of the most commonly discussed techniques of doing so could actually have detrimental ramifications in other areas, such as local air quality and its subsequent effect on human health. Those are the findings of a new study from the University of California in the US, which highlights a handful of ways in which GHG emissions can be reduced without compromising on air pollution.

The real cost of concrete

Priced at almost a half-a-trillion-dollar industry, concrete production is big business. However, a research paper published in the journal Nature Climate Change last month found that the damages caused by the practice – in the form of healthcare bills from air pollution and climate change consequences – amounted to approximately $335 billion per year, which is over 75% of the total income of the industry.

Concrete is comprised of three main components: water, cement and aggregate. Water is a precious resource in itself, while production of cement accounts for the largest chunk of costs associated with the industry, responsible for 32% of climate impacts and 18% of health costs. Making aggregate also contributed to both expenses (4% for climate and 34% for healthcare), while batching the concrete (mixing all of the ingredients together) also negatively impacted upon healthcare costs to the tune of 11%.

Analysing the options

What interested the researchers most of all was how to go about reducing these harmful effects. After evaluating the efficacy of eight different methods of reducing emissions from the industry, the paper concluded that some of the them sacrificed air quality in their immediate environment in order to avoid releasing large amounts of GHGs into the wider atmosphere.

Carbon capture and storage (CCS), for example, promises to remove carbon from the emissions stream before it can escape into the atmosphere, thereby bringing down a company’s CO2 footprint overall. However, while our ability to monitor concentrations of black carbon has advanced impressively, the technology to implement CCS on a commercial scale does not yet exist. What’s more, the practice could actually be counterproductive unless it is powered by renewable energy.

Identifying the most effective techniques

“As the cement and concrete industries make large efforts to reduce greenhouse gas emissions, it is critical that they remain mindful of the impacts decisions have on other environmental burdens to avoid undesired side effects,” commented Sabbie Miller, who served as the lead author on this project. “We clearly care a great deal about greenhouse gas emissions. But we haven't paid as much attention to health burdens, which are also are driven in large part by this demand.”

As a result, Miller and her colleagues identified the three most effective methods of reducing GHGs, which wouldn’t have a concurrently negative impact on local air quality. These included using cleaner kiln fuel in the production of the ingredients, replacing a percentage of the cement with more environmentally friendly alternatives and utilising clean sources of energy as much as possible. The research recommends investigating these avenues as a matter of priority, both in terms of helping the environment and reducing expenses incurred by the production of this commodity.