The potential of carbon storage in bio-based solutions to mitigate the climate impact of social housing development in Brazil

The increasing demand of housing in the Global South requires effective solutions to cover the corresponding deficit in the next decades. In Latin America, Brazil is the most populated Nation, which accounts for one-third of the total population and is the main contributor to carbon emissions. This study estimates how bio-based construction solutions, implemented in the Brazilian housing stock as alternative to conventional systems, can contribute to limiting the carbon emissions. Five different construction archetypes were considered, and a Material Flow Analysis model developed to estimate the demand of construction materials by 2050 under multiple scenarios. A carbon footprint assessment, which considers the dynamic effect of biogenic carbon sequestration and uptake, was finally performed to estimate the net Global Warming Potential. The results indicate that, if fast implemented, bio-concrete solutions with short-rotation vegetal species as bamboo, coupled with the lowest material intensity scenario, can reduce the cumulative carbon emissions by 65%, equal to 118 Mt of cumulative CO2-eq savings. Considering bamboo's widespread availability in Brazil's different climate zones, and in the Global South in general, such material presents a significant impact to mitigate the climate impact of social housing. However, the carbon saving intensity is largely affected by uncertainties on population growth and the type of biomass used in the concrete mixture. Therefore, further development of standards for the safe use of bio -concrete in construction is urgently needed, as well as the implementation of environmental policies to facilitate the market penetration of bio-based solutions in emerging economies.