Our total greenhouse gas emissions in 2008/2009 added up to 2,228,561 tonnes of carbon dioxide equivalent (CO2e). Owned emissions, those for which we are directly responsible, were 551,830 tonnes. Influenced emissions, those from contracts we operate on behalf of third parties, were 1,676,731 tonnes. Our emission split is shown in the graph below showing the trend over the last three years.
Our total emissions have increased by just over 170,000 tonnes CO2e compared to last year. This is mainly due to some changes in the way we are required to report on our emissions.
Significantly, we can no longer claim carbon savings on our use of renewable energy that we generate where we sell the renewable obligation certificates or on our purchase of certified renewable energy which resulted in over 360,000 tCO2e coming back on to our footprint. In previous years, these would have counted as reductions to our owned emissions.
In addition, the emission factor recommended for use by the government to convert grid electricity use into carbon emissions has been increased by 3% to reflect the change in the fuel mix of UK electricity generation. This also contributes to the increase in emissions in comparison to 2007/08.Our influenced emissions have increased very slightly (1%) due to improved standards for estimating gas network leakage coupled with the emission factor increase as discussed above.
Of the electricity we purchased in 2008/09 for our regulated business, 83% was certified renewable energy, up from 27% the previous year. This is the equivalent of 308,685 tCO2e. We also used just over 96GWh of renewable electricity generated ourselves from combined heat and power (CHP) plants, sludge incineration and hydropower plants, equivalent to just over 51,500 tCO2e. For more information please see our Energy section.
We recognise that the field of carbon accounting is constantly evolving and it’s important for us to ensure that our data is robust. Our greenhouse gas inventory, for the financial year 2008/2009 is undergoing independent third party verification by Achilles Group, to the requirements of the Landcare Research Certified Emissions Measurement and Reduction Scheme (CEMARS) including compliance with ISO14064 Part 1.