According to preliminary estimates from the Energy Information Administration, US carbon dioxide (CO2) emissions from fossil fuels decreased by 2.8 per cent in 2008 with transportation related emissions decreasing by around 5.2 per cent.
This represents the largest yearly decline in the transportation sector since 1990 – the next largest yearly decline since 1990 was in 1991 when the drop was 1.3 per cent.
Transportation however, remains the largest emitter of the end-use sectors with motor gasoline accounting for 58.7 per cent of the sector’s CO2 emissions followed by diesel fuel at 23.2 per cent.
Factors believed to have influenced the decrease include record-high oil prices as well as a decline in economic activity. Oil-related emissions dropped by six per cent – which accounts for the bulk of the overall reduction in energy related CO2 emissions.
However, there is a stark warning for those hoping that electric cars will represent an immediate solution to transportation emissions. When electric power sector emissions are considered as a whole rather than being allocated to end-use sectors they remain the single largest source of US CO2 emissions – they represent 41 per cent of the total emissions.
Yet there are some encouraging signs as in 2008, emissions from the electric power sector decreased by about 2.1 per cent, while power generation decreased by 1.0 per cent. The decrease in the emissions intensity of generation of 1.1% is partly due to an increase in wind-powered generation.
