Biochar (BC) is a carbon-dense substance produced via the pyrolysis process of biomass. It has since been touted for its significant capacity to detox soils and pollutants while increasing ecosystem services. This chapter pulls together the evidence that BC is effective at enhancing soil microbial biomass, retention of moisture, reduction of emissions of the greenhouse gas, and enhancement of crop productivity. The environmental benefits of BC are variable and context-dependent such as feedstock to be used, pyrolysis process, temperature, application rate, soil type and climatic conditions. Crucially, the biggest gains in yield and soil health have been on already disturbed soils or those lacking key nutrients. This chapter investigates the further uses of BC beyond soil quality amelioration, its inclusion in wastewater treatment plants, heavy metal adsorption processes, and renewable energy storage systems. While this chapter seeks to demonstrate the promise of BC, it does so through a discerning lens, examining the constraints and ecological implications of widespread BC implementation. Collectively, this offers a comprehensive, in-depth view of BC’s potential to further dual aims of more productive, sustainable agriculture and environmental protection, and recognition and debate of significant limitations that deserve focused research.