A technology-oriented optimization model of the world energy system is used to analyze sulfur and carbon mitigation strategies with respect to potential synergies and conflicts. A parametric approach with a stepwise reduction of maximum carbon dioxide (CO2) concentrations down to 400 ppmv in 2100, combined with stringent limits on sulfur dioxide (SO2) emissions, shows positive synergetic effects. Moreover, potential conflicts due to the negative contribution of sulfate aerosols to the climate change problem do not reach significant levels under the conditions investigated.