in the main text. Specifically, a small amount of heat is released directly from the
oxidation of organic matter during combustion. Assuming fuels at Donnelly Flats had a
heat of formation of 20.9 KJ/g and that organic matter was comprised of 50% carbon, the
fire emissions pulse would have been accompanied by 65 MJ of heat released into the
atmosphere. Averaged over year 1, this corresponds to 2 W m-2, but not all of this would
correspond to radiative forcing; some infrared radiation would be lost to space and would
not contribute to atmospheric heating. Further, over 80 years, the net effect of this
oxidation flux would be nearly zero because this is the time for biomass (and chemical
energy) accumulation within the ecosystem to equal that lost during the initial fire event.
We also did not consider aerosol indirect effects, including a reduction in cloud droplet
size and extended cloud lifetimes. Although uncertain, the sum of all aerosol indirect
effects are thought to contribute to a negative radiative forcing (1, 3, 45).