carbon footprint calculation

bogwalrus

I have hit a wall with trying to figure the following out.

If I drive 60km in my car with 4 free seats my carbon footprint will be X

If I drive 60km in my car with 4 passengers then technically my carbon footprint should be less but what is my X now and how do I determine each passenger x amount?

My brain hurts thinking about this.

draiochtanois

This post has been deleted.

bogwalrus

But if each of those passengers had driven themselves in their own cars their combined emissions would be 60g x 4 = 240g.

So if I decide to drive those passengers do I not take the above under account also?

bogwalrus

I think I have figured it out.

An average car will burn 10kg CO2 in a 60km trip so i have discovered.


so the drivers CO2 footprint will be + 30kg's if he picks up 4 passengers that would otherwise be driving.

40kg's (4 passengers) - 10kg (driver) = + 30kg's CO2


Is this right?

draiochtanois

This post has been deleted.

Yakuza

Don't overthink the situation.
A simple model to use would be : If you drive alone, your carbon footprint is X, if you drive with 4 passengers, your footprint (and that of each of your passengers) is X/5.

Ignore stuff like having to drive around to pick up the other 4 - assume you all start from the same point.

If the 5 of you would have driven separately then each of your footprints would be X (assuming cars with similar CO2 output)

5 people sharing a car = each person has one fifth of the footprint they would have had.

More realistically (esp. if the car was small and your passengers were heavy) then you might want to break up the CO2 emissions into a function of weight of the car and the passengers. A car with 5 passengers will emit more CO2 than one with 1 for the same journey.

Let's say the car was 1400kg and each of the passengers 100kg (let's say you were driving half the Leinster forwards )

Car + 1 passenger = combined weight of 1500kg, 60g CO2, footprint 60g per passenger.

If 1500kg emits 60g CO2, then it's 4g CO2 per 100kg

#Pax  Weight CO[SIZE="1"]2[/SIZE] Footprint/Pax
  1    1500   60   60
  2    1600   64   32
  3    1700   68   22.7
  4    1800   72   18
  5    1900   76   15.2

As you can see, it's not quite an linear relationship as you have to take the car's weight into account.

Or you could just ignore the above and go with what I first said

bogwalrus

That makes complete sense above.

Just a question though. If my yearly CO2 is lets say 13000kg's and I decide to start carpooling can I subtract the passengers Footprint off mine in an attempt to become more carbon neutral? Of course knowing the exact mileage etc.


I think I know the answer but just had to type it out.