Earth is a vernacular construction material with low environmental impact. Nonetheless, stabilisation is often used to increase the durability of the earthen construction, susceptible to water, abrasion and erosion. The most common stabilisers of modern times, such as hydraulic lime and ordinary Portland cement (OPC), have a significant impact on the carbon footprint of earthen construction. Therefore, alternative solutions for stabilisation must be attempted, such as recycled cement (RC). Indeed, RC allows to avoid CO2 emissions from clinker production, reduces the consumption of natural resources, and promotes the recycling of concrete and cement wastes. The study presents the savings in carbon emissions to produce compressed earth blocks (CEB) stabilised with RC rather than OPC. For comparison purposes, unstabilised blocks (UCEB) were also included. CEB stabilised with OPC or RC, have better mechanical behaviour and water resistance than UCEB. The modelling considered two scenarios: S1 with CEB produced at the same cement plant of the stabilisers; S2 with CEB produced at the construction site with soil retrieved from excavation and stabilisers produced in any Portuguese cement plant. In terms of carbon emissions, the substitution of OPC with RC allowed a reduction of about 2/3 of carbon emissions from CEB manufacture, consistent with the phase-out of clinker calcination. The carbon emissions for UCEB were estimated about 1/2 and 1/5 of the emissions from blocks stabilised with RC, ranging 0.027–0.113 kgCO2/CEB for different scenarios. The lowest carbon emissions were found for UCEB under S2, the closest to traditional construction practice.