Cement Leaves a Huge Carbon Footprint

As the most widely used construction material on the planet and with continually high, though volatile demand, especially in rapidly growing economies such as China, some 30 billion tons of concrete are poured each year to build large buildings, roads, bridges, dams, and a slew of other structures – it is the second most used resource on the planet after potable water.[1] 

While this is an obvious indicator of perpetual expansion of infrastructure and economic growth in the developing world, it’s also bad news for the environment, as the most crucial ingredient in its production, cement, due to an unavoidable chemical process called calcination, currently accounts for 8% of the world’s anthropogenic CO₂ emissions – an impact so large that it is comparable to the number of emissions from the whole of America or China, with the latter nation pouring more concrete in the last two years than the US did in the entire last century.[2] 

Estimates span a wide range, but, based on accounts from the sources used for this article from within the past 12 months, between 11 and 25% of the world’s total carbon emissions come from the construction industry; among the industrial sector, cement production, according to a study by McKinsey & Company, a consulting firm, generated 6.9 kg of CO₂ per revenue dollar, nearly five times of that of iron and steel, taking the top spot for the metric, with a more recent article from the firm noting that cement accounted for 4.5% of global GHG emissions and 7.0% of overall CO₂ emissions in 2019.[3][4] 

Ready-Mix Sustainability Initiatives

Concrete will likely continue to be the preferred construction material used globally for the foreseeable future due to the wide availability of limestone, used in making the cement that is a key element in its production, and its superb durability and performance characteristics – curbing demand will not be easy.  The pandemic, however, did create demand uncertainty by way of large decreases in demand in the US as growth slowed and increases in demand in China as the demand for Chinese manufactured products soared; the volatility did seem to cause pause enough for the industry to begin rethinking its overall cement strategy as investors and stakeholders realigned their own.[5]

Of the 75% reduction in CO₂ emissions reported as a possibility by McKinsey (see Net Zero and Beyond below), it is estimated that only 20% will come from operational advances – with the most viable energy-efficient measures having already been implemented throughout the industry – the rest, the firm asserts, will need to come from technological advances and new growth horizons, solutions very much still in development or having only been implemented in small scale.[6]  That’s not to ignore the importance of continued efficiency gains in current cement manufacturing facilities – again, it is expected that 20% of the overall decarbonization in the industry will come from these operational improvements; McKinsey separately laid out in this article a great strategy for digital improvements that can be implemented in the interim to meet 2030 sustainability goals, but, here, we’re primarily focusing on the more drastic CO₂ reduction efforts to meet 2050 targets.[7]

There are few alternatives to the use of concrete as a building material that are so versatile – with it being the marvelous material that it is and having earned its place as the most common building material for centuries – but as the voice of the customers and global stakeholders become ever louder, the current lack of options won’t stop ESG conscience firms (or those who spot the market potential) from trying to find them: from ‘hempcrete’ to a resurgence in interest in building with wood, particularly in the form of cross-laminated engineered timber, new options are being proposed in rapid succession, but durability, combustibility, and other issues make many possible solutions seem more like novelties than serious contenders – not to mention wood and other less durable construction materials not really being suitable for dense, vertical urbanization projects, lending more toward sprawling, suburban, horizontal building initiatives which also ultimately consume more energy and resources.

As mentioned, it is the unavoidable process of calcination that produces the carbon emissions that are wreaking havoc for the environment and capturing the gas before it can enter the atmosphere and storing it underground or utilizing it for other industrial purposes may be the best way to decarbonize the construction industry – initiatives commonly referred to as carbon capture, utilization, and storage (CCUS), technologies that are largely in development and not market ready.  The stored CO₂, for instance, can be used to make synthetic fuels or can even be injected back into the concrete to aid in the curing process – as CO₂ acts like water in hardening the concrete during the curing process by promoting chemical reactions resulting in the generation of calcium carbonate, a process actually making the concrete stronger and more durable than had it been cured with water alone.[8]  Combining the CO₂ hardening with substitution materials such as calcium silicates with higher ratios of silica to calcium oxide so that they require less heat than traditional calcination, The Economist suggests, would push the benefits further still.  The McKinsey study suggests that, while current methods could sequester some 5% of CO₂ generated during cement production, these newer technologies could net some 25-30%.[9]

There are also efforts to capture the gases directly from kilns – with the heating process from the kilns being one of the primary sources of the generation of carbon emissions.  Calix, an Australian firm, for instance is working on a system to use electricity to heat the limestone indirectly from outside of the kiln rather than inside, to where it is traditionally heated from the inside using carbon emitting energy sources.  The Economist asserts that this could potentially lead to completely green cement production in that the CO₂ that is captured using these alternate heating methods is not mixed with emissions from combustion gases from the fuels burnt inside the kiln and the electric energy used to indirectly heat the limestone could be provided from green sources.[10]

Of course, some would argue that most initiatives focus on controlling the emissions and that not enough attention is being paid to ensuring that they are not generated in the first place, which, from a quality practitioner’s perspective, seems like a fair argument – perhaps we’ve been too keen to accept the argument of the inevitability of the generation of greenhouse gases through the calcination process – advocates of such thinking are causing the conversation to tilt much more toward a decarbonization approach.  Taking the use of electric to heat limestone indirectly from outside of a kiln to a whole new level, then, a more recent report from The Economist highlights a proposal from an American firm in Colorado that is generating energy not from heat but from light, in turn being supplied via renewable electricity.  This process is also contingent on substituting materials in the cement production process, but this time relying on the use of chlorophyll-laden, photosynthesizing organisms called cyanobacteria – that’s correct, the firm is using bacteria as a material to enable energy production without heat to actuate a process called biomineralization to produce a crystal-rich aggregate material known as “bioconcrete”, and the photosynthesis compounds the benefits by subtracting CO₂ from the atmosphere rather than adding to emissions.[11]  You can read more about this process from the URL to the article in the footnotes – it’s worthwhile to do so as the uses get much more wild than this example when it starts exploring DARPA’s proposed uses of biocements.

The Concrete Barriers Blocking Sustainability Efforts

Going green doesn’t come cheap. 

Scalability stands in the forefront of the barriers to transforming the construction industry by adopting cement alternatives or findings carbon neutral or carbon negative ways to cure concrete – or move away from concrete altogether; many are skeptical that it can be done.  In the case of “bioconcrete” explored above, the US firm developing the product hopes to recoup costs by charging consumers a “green premium” for their blocks, and the article also notes that some jurisdictions, such as the states of California, Oregon, and Washington, are beginning to consider regulations that favor the use of reduced-carbon concretes, which will inevitably shift the burden of the costs to consumers should drastic efforts to reduce costs not quickly prove fruitful – for the firm noted, this cannot happen until they are able to move from producing in a lab to a new dedicated manufacturing facility, a move slated to occur next year, where it will be able to eventually drive down production costs.[12]

There is a need for a shift in mindset as well – many cement producing firms are likely to be content with the status quo, even with increasing scrutiny from the public, investors, and regulators.  Cement producers are not as accustomed to relying on partnerships or within the types of environments that many other industries have adopted causing it to lag behind, but with such a tight timeline for adoption of innovative technologies – with rapid advancement needing to come within the next five to ten years – and the necessity of such a dramatic shift in mentality, the industry is certainly left at a disadvantage and will quickly be playing catch-up.[13]

This is not only a matter of figuring out how to enable culture change in the construction industry; “green premiums” might simply not be viable in the current supply chain and there is currently little incentive to spend.  As the recent Economist article makes clear, it is not likely that the cost of experimental concrete products will be accepted by the industry on goodwill alone, but, with current costs of production, this unknown but assuredly massive premium for such alternate form of concrete will need to be paid for the manufacturers to turn a profit, or even to break even, highlighting the need to improve efficiencies in these experimental production methods to achieve economies of scale and drive down costs throughout the supply chain.[14]

Net Zero and Beyond: Why It’s Crucial for Quality Professionals to Step Up

Since the Paris Agreement in 2015, world governments have called for increasingly stringent greenhouse gas (GSG) emissions targets, setting a goal of keeping the world below + 1.5° C rise from pre-industrial temperatures – a target in which much of the world is today skeptical can be reached but also in which the international community doubled down on during COP27 in Egypt last month.  Research conducted in 2020 during the height of the COVID-19 pandemic from McKinsey & Company suggested that, while reaching the 2050 climate goals would be a massive global challenge, in principle, 2017-level emissions from cement production could be reduced in the industry by three quarters by 2050.[15]  Further, in late 2021, The Economist, suggested that not only could cement production realistically become carbon neutral but, with the proliferation of green technologies, could potentially go from adding CO₂ to the atmosphere to subtracting it.[16]

These results will not come about on their own, they must be tackled through a concerted global effort consisting of public and private enterprise.  The sustainability landscape has long seemed a bit of a free-for-all, but that is changing.  The message is becoming more urgent and more clear.  Two of the most exciting things to come from COP27 were a) the agreement for provision of “loss and damage” funding for vulnerable countries hit hardest by climate disasters, and b) ISO’s path toward standardization by way of IWA 42:2022 Net Zero Guidelines, the latter, I feel, will be of particular interest for experienced and budding quality professionals.

When exploring the challenges that are blocking innovation in this arena – whether it is in building a future that sees carbon neutral (or negative) cement production or any other type of production in any industry that is creating a negative impact on the environment, it should become clear that quality professionals, harnessing tools honed since the Second Industrial Revolution, will become crucial players in guiding us into the Fourth by supporting these emerging and disruptive technologies so that they can achieve economies of scale and offer viable solutions globally at costs that will allow for their adoption. 

Quality engineers and quality managers are formally trained in and regularly put into practice the disciplines needed: aiding and guiding in creating corporate strategy and setting quality objectives; implementing robust management systems and ensuring that their precepts are fully integrated into business operations; taking a systems and process approach to understanding how an organization operates so that its operations can be monitored and controlled; setting and auditing against quality standards, and taking corrective action when they are not met; setting and monitoring KPIs to ensure appropriate levels of efficiency and customer satisfaction; understanding the voice of the customer, to name a few. 

The affinity for those within the quality function to rise to exactly this type of challenge has been widely acknowledged – quality engineers and quality managers are frequently given additional responsibilities, for instance, in implementing and auditing requirements of integrated management systems, moving beyond quality requirements and incorporating elements of EHS, OH&S, etc.  In life sciences, this often manifests in combined QA/RA roles, where the quality professionals incorporate quality system requirements with other regulatory activity, making no distinction since quality requirements are regulated.  In the automotive industry, the quality engineer is often leading continual improvement initiatives using statistical tools such as DOE and SPC to identify where scrap is being generated or what parameters will best improve efficiency or performance.  Examples of how the quality function leads in these initiatives at all levels of the organization are abundant. 

The quality profession has long been a staple in many industries, but it is often misconstrued as being just quality control, metrology, etc. – not that those portions are not crucial elements of the disciple as a whole – and not always seen as a pivotal discipline that can guide an organization at every level to reach any of its strategic goals, ESG goals among them.  Organizations that have utilized these resources to help build robust management systems, conduct risk analysis, be involved in business continuity, etc., however, have reaped the most benefit from their quality department – and the profession is one whose time has come.  Like the organizations that employ them, quality professionals will need to start seeing their positions as more than a job – there is no clocking in in the morning and clocking out in the afternoon to never again think about how they’ve spent their day as if it had no implications outside their factory walls.  Instead, it’s time for quality professionals to take the lead in the international community’s efforts to standardize ESG terminology and metrics, determine best practices, and deploy and monitor results of effective management systems tailored for ESG initiatives and commitments. 

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[1] “How cement may yet help slow global warming,” The Economist, November 5^th, 2021.

[2] “How cement may yet help slow global warming,” The Economist, November 5^th, 2021.

[3] Thomas Czigler, Sebastian Reiter, Patrick Schulze, and Ken Somers, “Laying the foundation for zero-carbon cement,” retrieved on 12/7/2022 from https://www.mckinsey.com/industries/chemicals/our-insights/laying-the-foundation-for-zero-carbon-cement

[4] Thomas Hundertmark, Sebastian Reiter, and Patrick Schulze, “Green growth avenues in the cement ecosystem,” retrieved on  from https://www.mckinsey.com/industries/chemicals/our-insights/green-growth-avenues-in-the-cement-ecosystem

[5] Thomas Czigler, Sebastian Reiter, Patrick Schulze, and Ken Somers, “Laying the foundation for zero-carbon cement,” retrieved on 12/7/2022 from https://www.mckinsey.com/industries/chemicals/our-insights/laying-the-foundation-for-zero-carbon-cement

[6] Thomas Czigler, Sebastian Reiter, Patrick Schulze, and Ken Somers, “Laying the foundation for zero-carbon cement,” retrieved on 12/7/2022 from https://www.mckinsey.com/industries/chemicals/our-insights/laying-the-foundation-for-zero-carbon-cement

[7] Eleftherios Charalambous, Thomas Czigler, Ramez Haddadin, Sebastian Reiter, and Patrick Schulze, “The 21^st-century cement plant: Greener and more connected,” retrieved on  from https://www.mckinsey.com/industries/chemicals/our-insights/the-21st-century-cement-plant-greener-and-more-connected

[8] “How cement may yet help slow global warming,” The Economist, November 5^th, 2021.

[9] Thomas Czigler, Sebastian Reiter, Patrick Schulze, and Ken Somers, “Laying the foundation for zero-carbon cement,” retrieved on 12/7/2022 from https://www.mckinsey.com/industries/chemicals/our-insights/laying-the-foundation-for-zero-carbon-cement

[10] “How cement may yet help slow global warming,” The Economist, November 5^th, 2021.

[11] “Adding bacteria can make concrete greener,” The Economist, November 25^th, 2022.

[12] “Adding bacteria can make concrete greener,” The Economist, November 25^th, 2022.

[13] Thomas Czigler, Sebastian Reiter, Patrick Schulze, and Ken Somers, “Laying the foundation for zero-carbon cement,” retrieved on 12/7/2022 from https://www.mckinsey.com/industries/chemicals/our-insights/laying-the-foundation-for-zero-carbon-cement

[14] “Adding bacteria can make concrete greener,” The Economist, November 25^th, 2022.

[15] Thomas Czigler, Sebastian Reiter, Patrick Schulze, and Ken Somers, “Laying the foundation for zero-carbon cement,” retrieved on 12/7/2022 from https://www.mckinsey.com/industries/chemicals/our-insights/laying-the-foundation-for-zero-carbon-cement

[16] “How cement may yet help slow global warming,” The Economist, November 5^th, 2021.