Significant changes in how cement and concrete are produced and used are urgently needed to achieve deep cuts in emissions in line with the Paris Agreement on climate change.
Chatham House report
Published 13 June 2018
Updated 14 December 2020
ISBN: 978 1 78413 272 9
An ambitious vision for decarbonization of cement and concrete is not only a question of scaling up the use of low-carbon materials and putting the sector on a Paris-compatible pathway. It is also about meeting the vision set out in the SDGs: a more flexible, cleaner living environment for the 100 million people who are expected to move to cities over the next 10 years, and for the almost 4 billion people living in cities today.452
In the coming years, large quantities of concrete will continue to be used, and transforming how it is made to radically reduce the use of Portland cement is essential. As Section 3.3 explains, low-clinker and novel cements that release far fewer emissions in production are capable of matching the performance of Portland cement. Some already perform better than traditional cement in certain applications.
Today, these alternatives are rarely as cost-effective as Portland cement, and they face constraints in terms of raw material supply, resistance from customers and the difficulty of scaling up industry participation. The challenge is to overcome these barriers via a combination of policy mechanisms, enhanced collaboration, a concerted effort on disseminating best practice and targeted R&D. By creating the conditions for a race to the top, the sector could even become a low-carbon leader.
There is no simple formula or silver bullet. Moreover, while this paper focuses on the many exciting opportunities around clinker substitution and novel cements, greater action is also needed on energy efficiency, sustainable fuels and investments in CCS.
Yet it is entirely feasible that the cement and concrete sector can deliver the rapid decarbonization required to keep the rise in global temperature well below 2°C, and as close as possible to 1.5°C above pre-industrial levels. Current models indicate this can be achieved through incremental steps, and can rely to a significant extent on CCS technology. But other, more disruptive pathways could be accelerated by new business models, advances in material science, digital transformation and a revolution in the wider built environment.
Disruptive change in the cement and concrete sector could look quite different to what has been seen in other sectors. In the context of telecommunications or transport, the term ‘disruption’ is usually reserved for transformative changes that radically alter how people think, behave or do business, which often means rethinking from first principles. Such approaches are contrasted with ‘incremental’ or ‘sustaining’ innovations that simply improve existing products and processes.
This understanding of disruption only goes so far in the context of a heavy-industry commodity business such as cement and concrete. The physical importance of construction materials is unlikely to diminish in the same way, for instance, that newspapers have been replaced by news websites. Moreover, a ‘move fast and break things’ approach without safeguards – an approach seen in some sectors, particularly the digital sphere – is far from desirable in the cement and concrete sector, given the importance of maintaining safety and structural performance.
Disruption in the cement and concrete sector will hinge on incremental and transformative solutions alike. On the one hand, smarter approaches are needed to deploy a plethora of already available technologies, while matching solutions to specific locations and the right set of policies to enable such solutions to be scaled up. These individually incremental gains could add up to a step-change in emissions reduction. On the other hand, a much greater push is needed to make tomorrow’s transformative approaches, including the ‘holy grail’ of carbon-negative cements, commercially viable on a wide scale.
The prospect of transformative shifts coming from within the cement and concrete sector should be seen alongside new opportunities – or threats – coming from outside the sector
The prospect of transformative shifts coming from within the cement and concrete sector should be seen alongside new opportunities – or threats – coming from outside the sector. Innovations in connectivity, remote monitoring, predictive analytics, 3D printing and urban design are transforming traditional supply chains within the broader construction sector, with potentially large implications for concrete demand. Some of these technologies may seem to be over the horizon, but it is worth recalling how quickly the power sector changed once providers of renewable energy technologies such as solar and wind shifted from being niche players to disruptive competitors.
As these examples show, digital disruption and advances in manufacturing will play a critical role. Yet disruption in the sector is just as much about enabling people to enhance their skills, make better decisions and collaborate with others.
A global plan for cement sector decarbonization could be rooted in location-specific challenges and opportunities. The availability of a given material, the local climate and soil conditions, access to necessary finance and technology, and material/construction standards all vary across regions and determine the set of options available to cement and concrete producers. Connectivity between regions or cities matters too, not only in terms of infrastructure planning, but also for defining which construction materials can be economically traded.
This is about finding the optimal combination of technology, practice-related and policy solutions for a given location. For instance, while parts of Europe and the US are already feeling the effects of decreasing supplies of traditional clinker substitution materials, such as fly ash and blast furnace slag, China and India are currently producing huge volumes of these. Volcanic rocks and ash will become important in regions such as Italy, Greece and the west coast of North America, where these materials are plentiful.
Several studies suggest that calcined clays present a significant opportunity to increase clinker substitution around the world. These could have particular relevance for emerging and developing countries, especially in locations with existing stockpiles of suitable clays from ceramics industries, notably China and Brazil. Moreover, calcined clays are already being used in reconstruction efforts in Cuba, following damage from Hurricane Irma in 2017. This growing body of experience could lead to the widespread use of alternative materials to accelerate rebuilding after natural disasters.
Trade plays a small but significant and growing role in the availability of clinker substitutes, particularly for countries like Brazil where there is scarcity of key materials. Even within countries, transport is a significant factor. In China, there are underutilized supplies of fly ash in the west of the country, but a scarcity in the east. In Europe, a concentration of well-connected urban areas enhances the viability of concrete recycling.
The availability of construction materials is not just a question of cement and concrete. The viability and sustainability of potential bio-based substitutes for concrete, such as wood and hemp, also depend on local conditions. The environmental benefits could vary significantly, for example, between a well-managed Norwegian forest versus one in a country with weak forest governance.
Major regional infrastructure and connectivity initiatives may shape resource demand for a number of years. China has become a global enabler for infrastructure development through its overseas investments and its growing partnerships with countries involved in its Belt and Road Initiative. Ensuring that mega-initiatives such as these also create the right enabling environment for investment in sustainable infrastructure will require concerted efforts to collaborate and harmonize approaches at the global level.
High-performance building materials will be particularly important for enhancing resilience, including for flood defences and critical-infrastructure protection. Risks to infrastructure and cities posed by extreme weather events are especially serious for those places exposed to flood and hurricane damage, but also where residents need protection from extreme summer temperatures. Traditional concrete can come under strain when exposed to humidity and higher concentrations of atmospheric CO2. While concrete is likely to remain important in applications where the environment is challenging, novel, smarter and more adaptable materials are also needed.
Governments, especially in OECD countries and China, should consider giving a clear market signal by setting a target date for the achievement of net-zero carbon emissions in cement production and/or in the construction sector – recognizing that negative-emissions technologies may need to play a role.
A credible commitment by policymakers to decarbonize the sector could be a major driver of low-carbon innovation.453 In the past, anticipation of a Copenhagen summit deal and expectations of further tightening of the EU ETS led to a surge in innovative activity in research and in industry efforts such as the Cement Sustainability Initiative. However, patenting activity soon faded in the absence of a strong agreement and the lack of a high carbon price in most markets. Following the 2015 Paris Agreement, there is now a critical opportunity to recreate this momentum and to define a climate-compatible pathway for specific industrial sectors, including cement and concrete.
In many countries, governments are the largest procurers of construction products and services. (In the Netherlands, for example, public procurement has already helped increase demand for low-carbon cement.) Sub-national entities, cities, local authorities and housing corporations have a key role to play in exploring such approaches. A growing number of companies in various countries are also setting carbon-intensity targets for their construction projects. More generally, the major companies committed to 100 per cent renewable energy and electric vehicles could demonstrate further commitment to climate action by requiring the use of low-carbon materials in any buildings or infrastructure they choose to build.
New product standards have long been seen as vital for shifting industry practices and stimulating demand for lower-carbon products, but in the short term these are unlikely to provide sufficient incentive to expand the markets for such products or build sustainable supply chains around them. Current standards, in particular for concrete, hold back the deployment of very-low-clinker cements. Yet it can take decades for a new standard to be approved – and even once this exists, it can take a long time for customers to accept a new type of cement. One recent report suggests that there is little prospect of an overhaul of European cement and concrete standards.454 In the short to medium term, standards-setting bodies have a key role to play in developing the technologies needed to make more flexible approaches to standard-setting possible, such as accelerated durability testing.
Cement producers can reasonably expect that regulatory frameworks for reducing greenhouse gas emissions will come under greater scrutiny from civil society and governments
The other widely cited policy approach is carbon pricing. Carbon prices could create the necessary incentive to scale up investment in early-stage low-carbon cements, but sufficiently high price levels are unlikely for at least the next few years in key markets such as the EU, China, India and the US. Moreover, carbon prices alone are unlikely to deliver enough investment in new approaches fast enough to generate the deployment rates needed. 455 Evidence from other sectors suggests that breakthroughs can be made through more innovation-led policymaking. One option that has not yet been fully explored is differentiated carbon pricing on the final product, i.e. consumers would be charged for the carbon embedded in the building materials they procure.
Policymakers will need to consider how to encourage a more open approach to data among existing and future market players. This is not straightforward given the vertical integration of the sector today. Several of the opportunities outlined in this report for digital technologies to unlock the potential of low-carbon innovations rely on access to data so that advanced analytics can play a role.
Cement producers can reasonably expect that regulatory frameworks for reducing greenhouse gas emissions will come under greater scrutiny from civil society and governments, and that growing demand for cleaner air will continue to shape public opinion and policy. As confidence grows around the decarbonization of the energy sector and electric vehicles, other industrial sectors may be next in line. Some companies are better placed than others to move fast on decarbonization, or to profit from opportunities to move up the value chain. The launch of the Global Cement and Concrete Association in 2018 appears to represent a potential new coalition of the willing.
Given the different sectors and groups of actors involved, policymakers might want to adopt a multi-track, multi-level approach. In the context of focused deployment support for low- and alternative-clinker cements, this might look like the following:
1. Implementing and scaling up the use of available technologies and practices.
2. Identifying and developing the next generation of technologies.
1. Working with cement producers and academic institutions to:
2. Working with concrete producers to:
3. Working with clients, architects, structural engineers and contractors to:
Sharing experience and knowledge within and across industries, as well as between different regions around the world, should be encouraged and facilitated. International alignment on embodied-carbon targets and measurement for building materials is important as countries increasingly rely on imported materials. Policies directed solely at domestic material producers are unlikely to achieve sufficient reductions in embodied emissions.
The EU can play a powerful role in sharing lessons from its own attempts to shape innovation in heavy industries. Not only are many of the largest cement producers with the greatest R&D capacity headquartered in Europe, but the EU has also been behind some of the most advanced attempts to develop innovation pathways through its ETS. Exchanging knowledge with other countries and regions, such as China, that might hope to promote low-carbon cements through carbon-pricing schemes will be key. Moreover, a shift to using performance-based standards in Europe would be particularly effective, given that European cement and concrete standards are often followed elsewhere.456
Cities will play a critical role in delivering these decarbonization strategies, but today they rarely have access to all the necessary policy levers or the capacity for implementation. Cooperation between cities, including on shared lessons on the future of the built environment, will be important. Rapid shifts could be delivered through pilot schemes, smart public procurement, and incentives and regulations encouraging the use of waste materials in cements. Cities can work together to build the market for low-carbon cements through C40-type initiatives – a network of the world’s largest cities committed to addressing climate change – and city pledges.
To be effective and truly disruptive, cooperation will need to bring together new combinations of market actors capturing cross-sector opportunities and addressing cross-cutting challenges in the built environment. Long-term planning can be aided by innovative institutional arrangements to engage a new set of actors at national and regional levels and within different sectors. Existing initiatives, such as the National Infrastructure Commission in the UK,457 which acts as an independent body, collecting evidence and engaging stakeholders throughout the country, may play an important role in providing a long-term vision for the built environment.
If we are to achieve deep cuts in greenhouse gas emissions in line with the Paris Agreement, there can be no sectoral exceptions. The cement and concrete sector has to change. There are many potential pathways to lower emissions, and not all are likely to succeed. But as this report argues, there are clear approaches that can help create the conditions for the adoption of low-carbon materials and for private-sector leadership. The nature of the necessary interventions will, of course, differ across geographies and national settings.
Carbon-neutral or -negative construction will need to become the norm everywhere by around 2030.458 For this to be achieved, there needs to be a rapid increase in the use of building materials with zero or negative embodied emissions in the next few years.
Many governments in major economies have big plans for investment in infrastructure. Perhaps the most significant is China’s Belt and Road Initiative, which by some estimates will increase demand for cement by 162 million tonnes annually by 2020.459 Provisional assessments of President Donald Trump’s infrastructure plan for the US suggest it would require approximately 30 million tonnes of cement per year up to 2021.460 A major road-building initiative in India is projected to require 4 million tonnes per year over a five-year period.461
It would be a game-changer if such megaprojects specified the use of lower-carbon cements or alternative products for a large share of their construction. There are many examples of governments already setting ambitious requirements. In the UK, the concrete for London’s Crossrail project must have a minimum cement-replacement content of 50 per cent. Since 2015, the United Arab Emirates has required all major infrastructure projects to use cements that contain at least 60 per cent blast furnace slag or fly ash. Multilateral development banks will have a vital role to play in encouraging or requiring such approaches in the projects they help finance.
Yet while major infrastructure projects are well suited to the introduction of novel products, another test is whether governments start to commit to ambitious sustainability targets for social housing or even all new buildings, which would likely trigger profound changes in market structure.
The ultimate goal here should be material and technology neutrality at the building or city scale. This would guide consumers to choose not only more sustainable solutions but also the most appropriate option for any given project, while allowing suppliers to innovate to meet those demands. Policies and regulations should encourage a shift towards functional or performance-based specifications, rather than prescribing or forbidding the use of a particular material.
In the meantime, targets for embodied carbon in construction materials could be introduced with little risk of carbon leakage,462 helping to align incentives and responsibility for net-zero-emissions construction along the value chain. This matters because concrete often accounts for a small share of the total cost of construction projects, and the end-users in construction may be better able to absorb the costs of mitigation.
As demand for low-carbon materials is ramped up, a host of changes will be needed in material supply chains. Governments will need to find ways to incentivize investment in distribution networks for clinker substitutes, and in the additional processing equipment and storage infrastructure that may be required to scale up the provision of lower-carbon cements. Incentives to use clinker substitutes and novel cements will need to be accompanied by best-practice dissemination and support to make the use of innovative products viable. The use of waste materials and other cement additives, for instance, requires specialist knowledge and equipment that are often lacking in emerging markets.
Technologies take a long time to get from laboratory to market in many sectors, but low-carbon cements seem to face particular challenges in bridging this ‘valley of death’. A considerable push is required to get the next generation of low-carbon cements out of the lab and into the market.
Given the huge scale of cement production, it is not sustainable to provide long-term subsidies for low-carbon alternatives. Instead, the goal should be to identify a suite of materials, technologies and approaches that have the potential to rapidly become more cost-effective once deployed at scale, and to focus support for innovation in these areas.
Not all novel approaches will succeed, but those that do may well have significant decarbonization potential. As well as additional funding for R&D and demonstration, new models of cooperation around innovation between companies and across borders will be important.
The digital revolution will not remove all the physical and economic challenges of decarbonizing cement and concrete, but it can make a dramatic difference – whether via optimizing supply chains, enhancing collaboration, or providing workers in all relevant fields with the data needed to make economically viable and technically appropriate decisions on low-carbon materials. Digital tools, for instance, will play a key role in building the market for novel cement and concrete products by addressing misinformation, enhancing collaboration, disseminating best practice and reducing asymmetries in access to relevant information at different points along the value chain. These tools are especially important for growth markets such as China, India and countries in sub-Saharan Africa.
Industrial sectors also offer some of the most promising near-term opportunities for using machine learning to increase profit margins and reduce emissions. Today, the application of AI in industrial and commercial applications is primarily focused on optimizing logistical operations in the high-tech, relatively controlled environment of industrial plants, or on identifying promising new materials. But many of the recommendations in this report depend on decisions being made based on factors ranging from material availability to expectations of material performance in specific contexts. Machine learning is well suited to this challenge. Where it is not yet capable of producing fully fledged autonomous decisions, it could still have powerful applications in the sector: for instance, by providing a clear set of decisions for workers to select from, drawing on a wealth of historical and real-time data.
Several of the solutions proposed above depend on well-coordinated international efforts, whether on research, best-practice dissemination or procurement. The cement and concrete sector encompasses multiple types of actor, different country contexts and different private-sector interests. Coordinating these and orienting them towards a net-zero-emissions pathway will be key.