The US Environmental Protection Agency suggests a yield of 8.887 kilos of Co2 per gallon of petrol burnt. Those are US gallons.
Another site, using larger UK gallons and factoring in the extraction/production and transport costs incurred in delivering the petrol to the car, that it might then be burned by the car on our streets, gives a per gallon yield of 14.3 kilos of Co2. I'll write that again: 14.3 kilos. That's astonishing. It looks like generating Co2 is the thing fossil fuels do best when burned in air; the heat and light generated mere side effects, accidents, feeble epiphenomena.
We'll stick with 14.3 kilos per gallon as a yardstick. The internet suggests a UK national average car commute distance of 10 miles. I suspect it could be fractionally higher in Northumberland, but we'll stick with 10 miles, or 20 miles round trip. There are nearly 700 parking spaces at Northumberland County Council's HQ, County Hall, regularly filled such that overspill spaces are used on the approach road, verges have been grasscreted and formerly pedestrian block paved precincts surrendered to add capacity. (As an aside, a little hands on research/direct observation suggests a single occupancy rate of vehicles parking up at CH of 98.5%) I doubt anyone knows for sure how many spaces there are. I've tried totting them up from Google maps satellite view but invariably lose count. A bit like Galleon's Lap in Winnie the Pooh's Hundred Acre Wood, that mysterious stand of fir trees no-one has been able definitively to count; are there 63 or 64? Except these are dead slabs of oily concrete and tarmac to store idle heavy machinery, and not fir trees. Last time I tried I blacked out at 687, overwhelmed by the sheer scale of the weeping tarmac wound. Let's, conservatively settle on 700.
700 x twenty miles x 5 days a week x 50 weeks a year (there are 8 bank holidays) = 3,500,000 car miles a year. I'll write that again: County Hall generates 3,500,000 car miles - almost exclusively single occupant car miles - a year.
We need an average miles per gallon figure to proceed. Car manufacturers are notoriously dishonest about the environmental hazard their product represents. The industry in the UK claims 50mpg, but these figures are widely understood not to translate to real world driving conditions. A US site offers 24.9mpg or something, but US gallons are smaller. Scaling up proportionately gives a UK figure of 29.9mpg. I don't know how authoritative this site - https://www.nimblefins.co.uk/average-mpg - is but I'm persuaded to proceed with their 38.8mpg. 3,400,000 car miles divided by 38.8mpg = 87,629 gallons, times 14.3 kilos Co2 per gallon = 1,289,000 kilos Co2, or 1,289 metric tonnes of Co2 a year.
There are 8,760 hours in a calendar year. That's 147 kilos each and every hour of the day, 7 days a week, 52 weeks a year. Co2 emissions of 147 kilos per hour sit beyond higher end estimates of the hourly yield of a jumbo jet at cruising speed.
The DfT's 2008 [yes, it was that long ago] Essential Guide to Travel Planning gives the national average annual cost to the provider of a single car parking space to be around £400. See other posts for a play with this. Parking at CH is offered free to staff.
Conclusion: at County Hall alone, something like £272,000 of public money are spent subsidising the emission, by single occupant car commuters, of something like 1,289 metric tonnes of Co2 every year, comfortably equivalent to keeping a Jumbo jet airborne perpetually. For a visual sense of NCC's Green Workplace Travel Planning commitment at its own HQ, picture a Jumbo flying in circles above the battlements of County Hall, day and night, ceaselessly, never landing.
It's been up there 40 years already.
