This dissertation comprises three essays on carbon dioxide (CO2) pricing policies focusing on its relationship with two key societal goals: environmental justice (EJ) and the clean energy transition. Traditionally, CO2 controls often apply uniform prices without accounting for their impact on the spatial distribution of co-pollutants, raising equity concerns. The first essay theoretically examines CO2 pricing under EJ constraints that limit the worsening of the existing inequities in co-pollutant exposure. The analysis shows that uniform CO2 pricing is optimal if and only if co-pollutant regulation is also optimal, conditional on satisfying EJ constraints. Otherwise, optimal CO2 prices deviate from the standard uniform pricing approach. The second essay empirically investigates whether regional carbon markets affect disparities in sulfur dioxide (SO2) exposure, particularly in low-income and racially marginalized communities. Focusing on the Regional Greenhouse Gas Initiative (RGGI), a CO2 cap-and-trade program launched in 2009 in the northeastern and mid-Atlantic United States, this essay finds that, while overall SO2 exposure declined in regulated areas due to RGGI, counties with higher Black populations and counties with lower incomes experienced relatively smaller reductions. Similar disparities in SO2 exposure co-benefits, based on race, were also observed in neighboring unregulated regions. The third essay evaluates whether, in RGGI participating states, the CO2 market has accelerated the shift away from fossil fuels toward renewable energy. Findings suggest that RGGI significantly reduced fossil fuel-based electricity generation, primarily through declines in coal-fired generation. However, the program’s effect on renewable generation was positive but statistically insignificant. Together, these three essays contribute to the environmental economics literature on CO2 prices by highlighting how uniform pricing intersects with EJ and clean energy transition goals.