This report summarises the main conclusions of an inventory and analysis on low-CO2, eco-efficient cement-based materials, carried out by a multi-stakeholder working group initiated by the United Nations Environment Program Sustainable Building and Climate Initiative (UNEP-SBCI). The cement industry has already achieved significant reductions in the CO2 emissions associated with cement production, mainly through increased energy efficiency, use of alternative fuels including a wide range of wastes, as well as through clinker substitution. In addition to these traditional solutions, carbon capture and storage (CCS) has been identified as necessary to achieve the remaining reductions needed to keep global warming to below 2°C vs. pre-industrial levels.