To determine emissions from the fossil carbon fraction of the
waste burned in the incinerator, we used CO2 emissions detected by
continuous site-specific measures (SIENA AMBIENTE S.p.A, 2012);
the CO2 generated by the combustion of the non-fossil carbon
fraction was subtracted (Table S.10 in the Supplementary on-line
material). Anthropogenic emissions from natural gas used to
maintain the combustion temperature in furnaces was also subtracted
from the measured tons of CO2 released by incineration
(Nate S.4 in the Supplementary on-line material). Emissions due to
natural gas combustion in the incinerator must be calculated
separately in order to avoid double-accounting