Emission sources not reported This section of the report details the emission sources on which we have not reported and provides the reasons behind our decisions. Only a minority of the offices we operate directly make use of gas and we have included this in our emissions from combustion of fuel. We do not have distinct data on heat/steam for our other offices as this is most likely embedded in the office service charges that we pay. As a result, we have not currently reported on purchased heat or steam. In future we will devise a methodology to estimate the emissions associated with heating requirements for which we are responsible.