Suppose households increase the efficiency with which they use gas so that they can heat their homes to the same degree for the same time each day, but using less physical gas. This will reduce carbon emissions directly emitted by households. However, where households demand less gas, this will also reduce output requirements in the energy supply chain(see figure below). Thus, further reductions in emissions may be expected in the utility sectors themselves (gas, electricity and water supply) but also further up the supply chain, including the extraction of oil and gas and other sectors (service and industrial) within UK and overseas supply chains. Reflecting this argument, our project proposes use of a metric called a Carbon Saving Multiplier (CSM)that reports the total kg (or tonne) of carbon saved throughout the energy supply chain per kg (or tonne) directly saved within the household sector.