Belite Calcium SulfoAluminate (BCSA) cements, also known as sulfobelite cements, have been developed as OPC substitutes.BCSA cements contain belite as main phase (>50 wt%) and yeelimite as the second content phase (~30 wt%).BCSA are less calcite demanding materials than OPC, with the consequent diminution of carbon dioxide emissions from decarbonation in the kiln.Although BCSA cements have been proposed as a sustainable alternative to OPC, an important technological problem is associated to them: these materials develop low mechanical strengths at intermediate hydration ages (3, 7, and 28 days).One of the proposed solutions to this problem is the activation of BCSA clinkers by preparing clinkers with high percentage of coexisting alite and yeelimite.These clinkers are known Belite-Alite Calcium Sulfoaluminate (BACSA) cements.Their manufacture may produce 15% less CO than OPC.Alite is the main component of OPC and is responsible for early mechanical strengths.The reaction of alite and yeelimite with water will develop cements with high mechanical strengths at early ages, while belite will contribute to later curing times.Moreover, the high alkalinity of BACSA cement pastes/mortars/concretes will facilitate the use of supplementary cementitious materials with pozzolanic activity that also contribute to decrease the CO footorint of these ecocements.