Meta, Holcim, and other major firms are investing heavily in startups working to reduce carbon emissions in cement production, a critical step for combating climate change. Cement, a key material in concrete, accounts for massive CO2 emissions, and startups like CarbonBuilt, Sublime Systems, Cocoon, and Carbon Limit are leading the charge with innovative solutions. From Meta's collaboration with CarbonBuilt to Holcim's backing of Sublime, these partnerships aim to make low-carbon cement mainstream, reducing the environmental impact of global infrastructure.