Reducing our carbon emissions
We generate direct carbon dioxide emissions predominantly from our vehicles (see diagram below) but also from heating and lighting of buildings and from business travel.
The carbon dioxide emissions from our buses are directly related to fuel consumption. A wide range of factors influence this such as age and weight of vehicle, engine type, average speed, driving technique, nature of route and the number of passengers on the bus. Buses have in general become less fuel-efficient in recent years due to requirements for additional abatement technology that reduces other pollutants such as nitrogen oxides and particulates.
A key part of our Climate Change Strategy is to seek to reverse this trend through our vehicle procurement policy where we are working with our vehicle suppliers to provide more fuel-efficient vehicles.
Achieving emission reductions
Key developments
- We have achieved a 4% reduction in our total carbon dioxide emissions since 05/06. This equates to 28,749 tonnes of carbon dioxide.
- Further savings of 13,909 tonnes of carbon dioxide have been achieved through the use of 5% biodiesel (calculated on a lifecycle basis). This would account for a further 1.9% saving.
- We have reduced the energy usage in our buildings by 7.4% over the past twelve months. This equates to 1,796 tonne reduction in our carbon dioxide emissions.
- All our bus drivers will receive training in the Smith System Defensive Driving technique by June 2008, which promotes more fuel-efficient driving.
- We are rolling out a point of issue fuel management system. This captures fuel issue and mileage data at source vehicle-by-vehicle that will significantly increase our ability to understand the factors that influence fuel efficiency in order to secure further fuel efficiency improvements.
- We are working with our suppliers to improve the fuel efficiency of new EURO IV engines.
We have exceeded our emissions reduction target of 5% on 05/06 levels by 0.9%, achieving a total saving of 42,658 tonnes of carbon dioxide. This results from reductions in fuel consumption, reduction in energy use in buildings and the introduction of biodiesel.
Improving fuel efficiency will be our focus going forward. Our newer vehicles are now more fuel-efficient than their predecessors but not the far older vehicles they replace. The impacts of fleet replacement will therefore take some time to realise.
Our carbon footprint is calculated in accordance with the Greenhouse Gas Reporting Protocol. The UK Bus total emissions figures include fuel usage, gas and electricity usage in properties and business travel covering rail and flights.
In addition to the emission reductions shown opposite we have also reduced emissions by 13,909 tonnes CO2e through the use of a 5% biodiesel blend. When calculating emission reductions associated with the use of biofuel, it is important that they be calculated on a lifecycle basis so that the additional emissions associated with biofuel manufacture compared to fossil fuel manufacture can be taken into account. Current international standards on reporting annual GHG emissions (such as the WBCSD's GHG Protocol used in this assessment) do not currently allow for this level of analysis so the reduction has been calculated separately from the annual GHG assessment. The emission factors used in the calculations have been selected on the basis of current best available evidence.
