Carbon footprint

Our owned and influenced greenhouse gas emissions in 2007/08 totalled 2,059,103 tonnes of carbon dioxide equivalents. Owned emissions are those for which we are directly responsible, influenced emissions are those from contracts we operate on behalf of third parties. Our emissions are shown in the graph opposite.

This year. we are using two methods of recording our carbon footprint. The conversion factor recommended for use by the government to convert grid electricity usage into carbon emissions has been increased* to reflect the change in the fuel mix of UK electricity generation from being less nuclear and more coal. Also the water industry has agreed a new joint approach to measuring its emissions so there have been some minor changes to the calculation methodology.

As a result, we are using both the previous method of calculation to enable comparison of trends and the new method of calculation.

The scope of our emissions counting has also changed with the sale of our Vertex business, our electricity assets and our facilities management company. These organisational changes are included in our carbon accounting and target setting.

As a result of these accounting changes, the headline number for our owned emissions is a decrease of some 76,000 tonnes carbon dioxide equivalent (CO2e) from last year, despite the increase in the electricity conversion factor. This is down to a combination of factors -  we reduced electricity consumption and we also purchased 200GWh of zero emission rated green energy. 

The total emissions figure for 2007/08 is slightly different to that reported in our Annual Report and Accounts 2008 and the paper version of the 2008 Stakeholder Report. This is due to an amendment made to the gas shrinkage figures after publication of the reports. The numbers shown here are the finalised figures and it should be noted that the amendment has not affected the level of our owned emissions upon which our reduction targets are based.

For further information on our greenhouse gas emissions see the performance table

Owned emissions broken down by source for 2007/08 are shown in the graph above. 

Explaining each in turn, grid electricity relates to our use of electricity from the national grid. Process emissions are emissions of methane and nitrous oxide that occur as a result of our water and wastewater operations, such as thickening of sludge and incineration. Transport fuels include our fleet fuel purchase and our business mileage. Other fuel use includes fuel oil, diesel and gas used in heating and back-up generators. Finally, rail and air travel contribute 0.1 per cent of our owned emissions and therefore are not visible on the chart.

 *from 0.43 to 0.523 kg of CO2e per kWh