Remember when Expedia.com offered the opportunity to offset the carbon emissions of your flight with some sort of e-carbon credit? For about $15 you could negate the CO2 from your flight by paying for like new trees or something. I'm sure they simply calculated the average fuel usage for a trip of XX miles, and multiplied by the carbon intensity of the fuel used for the flight. What I'd love to be a part of is looking at the real footprint of a plane ticket (while being exempted from having to partake in the necessary regressions).
The difference b/t what I want to do, what's probably done: that plane is flying with or without you - it's not like a car's carbon footprint which is entirely dependent on your driving habits. You'd actually have to calculate the likelihood that your ticket creates a tipping point, wherein a bigger plane is needed to transport everyone. Multiply that probability by the additional intensity of a larger plane, and you've got the carbon footprint of a plane ticket.
I don't know how this would work with the standby system, but it probably further diminishes the probability of you being of consequence. Additionally, I'm making a strong assumption that airlines react to demand by allocating larger or smaller planes to each trip. i really have no idea if this is the case, as the capacity to be responsive would take on an additional burden (i.e. having to store additional planes in the hanger). Predictive modeling would ballpark it pretty well, which I'm sure already occurs, but I'd like to know the extent. Then I could extort carbon offset companies by demonstrating how much the market signal of a single ticket really is, the carbon cost it really incurs, and get paid not to tell anyone else.
Willing to go in 50/50 with someone possessing in-depth knowledge and personnel access in the airline industry. Immediate proceeds will go towards paying for the ticket I just purchased, as I missed my plane and am sitting in the airport waiting for a second flight I definitely didn't budget for.