A draft report of the US Environmental Protection Agency’s (EPA) Inventory of US Greenhouse Gas Emissions and Sinks: 1990-2008 indicates that transportation emissions fell by 5.7 per cent – the largest annual fall since 1990.
The report outlines that overall greenhouse has emissions have decreased by 2.9 per cent with CO2 emissions in the transportation sector dropping from 1,893.8Tg CO2 in 2007 to 1,785.3Tg CO2 in 2008. This is the largest annual change in absolute or percentage terms since records began in 1990.
The transportation end-use sector accounted for 1,818.1Tg CO2 in 2008 with 32 per cent of CO2 emissions, 24 per cent of CH4 emissions and 65 per cent of N2O emissions coming from fossil fuel combustion. Light duty vehicles represented 62 per cent of CO2 emissions, with medium and heavy trucks accounting for 22 per cent and commercial aircraft seven per cent.
Overall, from 1990 to 2008 transportation emissions have increased by 22 per cent – largely due to increased demand for travel as well as the stagnation of fuel efficiency across the US vehicle fleet. Vehicle miles travelled have also increased by 37 per cent over the 18year period and there has been a significant increase in air travel and freight transportation.
According to the EPA, the decrease in 2008 is largely due to a decline in economic activity and the increased price of transportation fuels.
