Making Concrete Change Innovation in Low-carbon Cement and Concrete (original) (raw)

Each year, more than 4 billion tonnes of cement are produced, accounting for around 8 per cent of global CO2 emissions Making Concrete Change: Innovation in Low-carbon Cement and Concrete Executive Summary vi | #ConcreteChange all will need to be deployed at scale to meet the decarbonization challenge. Some of these solutions are well recognized and common to other sectors: for instance, the energy efficiency of cement plants can be increased, fossil fuels can be replaced with alternatives, and CO2 emitted can be captured and stored. The main focus of this report, however, is on those emissions mitigation solutions that require the transformation of cement and concrete and are thus unique to the sector. More than 50 per cent of cement sector emissions are intrinsically linked to the process for producing clinker, one of the main ingredients in cement. As the by-product of a chemical reaction, such emissions cannot be reduced simply by changing fuel sources or increasing the efficiency of cement plants. This report therefore focuses on the potential to blend clinker with alternative materials, and on the use of 'novel cements'-two levers that can reduce the need for clinker itself by lowering the proportion of clinker required in particular cement mixtures. Despite widespread acceptance among experts that these are critical, they have received far less policy focus. Well-known barriers stand in the way of deep decarbonization of cement. The sector is dominated by a handful of major producers, which are cautious about pioneering new products that challenge their existing business models. In the absence of a strong carbon-pricing signal, there is little short-term economic incentive to make changes. Alternative materials are often not readily available at the scale required. Meanwhile, architects, engineers, contractors and clients are understandably cautious about novel building materials. Implementing new practices also implies a critical role for millions of workers involved in using concrete across the urban landscape. Low expectations around the prospects for a radical breakthrough in cement production are reflected in the limited attention given to the sector in key assessments of low-carbon pathways in recent years. 5 As one recent report notes, 'When cement emissions are mentioned at all in public debate, it is typically to note that little can be done about them.' 6 There is, however, a growing sense not only of the urgency of the need to decarbonize cement production, but also of the expanding range of technological and policy solutions. The range of major organizations now working on relevant strategies includes the UN Environment Programme (UNEP), the International Energy Agency (IEA)-working with the industry-led Cement Sustainability Initiative (CSI)-and the Energy Transitions Commission, an initiative involving high-level energy experts and stakeholders aimed at accelerating the transition to low-carbon energy systems. For decision-makers, more insight is needed into the potential for scalable, sustainable alternatives to traditional carbon-intensive cement and concrete. For this report Chatham House worked with CambridgeIP, an innovation and intellectual 5 The New Climate Economy's Seizing the Global Opportunity report mentions energy-intensive sectors such as cement, chemicals and iron and steel 'where emissions are large and significant reduction poses undeniable challenges', without spelling out a potential pathway for reduction of those emissions.