A combination of technology and policy solutions could provide a pathway to reducing direct carbon dioxide emissions from the cement industry by 24% below current levels by 2050, according to a new report by the International Energy Agency (IEA) and the Cement Sustainability Initiative (CSI).
The technology roadmap—Low-Carbon Transition in the Cement Industry—updates the first global sectoral roadmap produced in 2009. It aims to identify and develop international collaborative efforts and provide evidence for public and private sector decision-makers to move towards a more sustainable cement sector that can contribute to long-term climate goals.
The cement sector is the third-largest industrial energy consumer in the world, responsible for 7% of industrial energy use (10.7 EJ), and the second industrial emitter of carbon dioxide, with about 7% of global emissions.
Cement production involves the decomposition of limestone (calcium carbonate), which represents about two-thirds of the total CO2 emissions generated in the process, with the remainder of CO2 emissions being due to combustion of fuels. Thus despite considerable progress on energy efficiency, the use of alternative fuels and clinker replacements, the sector has the second-largest share of total direct industrial CO2 emissions, at 27% (2.2 gigatonnes of carbon dioxide per year [GtCO2/yr]) in 2014.
Cement is the key ingredient of concrete—which is used to build homes, schools, hospitals and infrastructure, all of which are important for quality of life, social and economic wellbeing.
As global population rises and urbanization grows, global cement production is set to increase between 12 to 23% by 2050.
Despite increasing efficiencies, direct carbon emissions from the cement industry are expected to rise by 4% globally by 2050 under the IEA Reference Technology Scenario (RTS), a base case scenario that takes into account existing energy and climate commitments under the Paris Agreement. Realizing the IEA’s more ambitious 2°C Scenario (2DS) by 2050, which seeks to limit average global temperature increases to 2°C, implies significantly greater efforts to reduce emissions from cement makers.
The low-carbon transition of the cement industry can only be reached with a supportive regulatory framework as well as effective and sustained investments. Meeting the RTS already requires additional cumulative investments compared to the status quo. Achieving the transformation described by the 2DS could mean up to a doubling of these investments compared to the RTS. Governments, in collaboration with industry, can play a determinant role in developing policy and regulatory mechanisms that unlock the private finance necessary for such a boost in investment.
As a flagship sectoral project of the World Business Council for Sustainable Development (WBCSD), the CSI is a global effort currently gathering 24 major cement producers having operations in more than 100 countries and who have integrated sustainable development into their business strategies and operations.
The roadmap uses a bottom-up approach to explore a possible transition pathway based on least-cost technology analysis for the cement industry to reduce its direct CO2 emissions in line with the IEA’s 2DS. Reaching this goal would require a combination of technology solutions, supportive policy, public-private collaboration, financing mechanisms and social acceptance.
Improving energy efficiency and switching to alternative fuels, in combination with reducing the clinker content in cement and deploying emerging and innovative technologies like carbon capture and the use of alternative binding materials are the main carbon-mitigation methods available in cement manufacturing.
Further emissions savings can be achieved by taking into account the overall life cycle of cement, concrete and the built environment. This can include optimizing the use of concrete in construction by maximizing design life of buildings and infrastructures, encouraging reuse and recycling, reducing waste and benefiting from concrete’s properties to minimize energy needs for heating and cooling of buildings.
The roadmap outlines policy priorities and regulatory recommendations, discusses investment stimulating mechanisms and describes technical challenges with regard to research, development and demonstration.