This graph shows the CO₂ produced as a result of electricity and gas usage in the first half of 2007. Note the increasing use of gas for heating as the temperature drops. Also note that in the last week of the graph how the consumption of electricity jumps. This was the week that very low temperatures coincided with the failure of our gas central heating. The oil filled (Dimplex style) heaters we borrowed kept us warm, but at quite a cost.