514.8 kg of CO2 TweetYour own mileage may vary. See information below.
Data used for emission per mile traveled is based upon official UK data from the Department of Environment, Food and Rural Affairs, originally published in 2001. Emissions for other fuels can be found on Defra's Environmental Reporting page.
The car mileage figure is based upon an average UK family car returning 29mpg. If your car fleet returns better figures on average, (or you driving a smaller car achieving (say) 40mpg, or regularly share a car) then you could adjust the mileage accordingly to estimate CO2 emissions. In choosing a figure, it's worth bearing in mind that official published fuel consumption figures are calculated under ideal conditions (a warmed up engine, no sharp braking or accelerating) and can be at least 10-15% better than achieved by most drivers in real life.
Aeroplane emissions are very hard to estimate. The figure used here is based upon short-haul (European) flights in economy class - add up to 50% for business class travel with lower seat densities. However there is some evidence that there is at least as much Global Warming effect again from other aircraft emissions in the upper atmosphere, such as ozone created from NOx or condensation trails, than solely from the CO2 emitted on the journey.
Source: National Energy Foundation, UK
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