in both cases large uncertainties remain sometimes they are due to methodological differences or different estimations for the value of a statistical life the metastudy by burtraw et al as far as air pollution is concerned power sources can largely be split into two groups i carbonbased electricity sources including fossil fuels and biomass with coalfired plants causing damages that are considerably higher than those from natural gas oil or biomass ii sources that have impacts on air pollution from lowcarbon electricity sources nuclear wind solar hydro geothermal and tidal are either negligible or zero although some indirect emissions could arise during production