If your measuring climate impact, then the "warming equivalent" is the correct metric and pure co2 is the wrong one. Am I misunderstanding what you're saying?

The problem is that we're comparing 2 numbers, one is "warming equivalent" and the other doesn't seem to be. We need to adjust one or the other, but which one we adjust shouldn't matter here.

No, it does matter, we should use Warming Equivalent. "Warming equivalent" is the correct metric. Warming equivalents are typically given in Tons CO2 equivalent. It's a way of converting methane and NO2 and other more powerful greenhouse gases to their CO2 equivalent. It's the standard metric anytime we're examining the climate impacts of actions.

In the case of gasoline powered cars, I believe they just put out CO2, the other components are pretty negligible. So you can directly compare the warming equivalent of planes to the pure CO2 of cars, it's a reasonable comparison.

It's worth double checking that last thing, it's been a minute since I looked at the numbers, but I'm about 85% sure of it.

Interesting... I just learned N2O is 300x worse than CO2. I don't know how to make a better comparison then. Some numbers I can find:

"Aircraft engine emissions are roughly composed of about 70 percent CO2, a little less than 30 percent H2O, and less than 1 percent each of NOx, CO, SOx, VOC, particulates, and other trace components including HAPs." [1]

For gasoline the ratio seems to be 51% CO2, 47% H2O, and 0.9% nitrogen oxides, and 1.3% other stuff (excludes nitrogen). [2]

Water vapor isn't considered to be relevant when calculating CO2 equivalents so we can ignore that. [3]

But I'm not sure how much the difference in NOx contribution is... given ground level emissions aren't the same as high-altitude and such.

On the face of it it seems unlikely to me that the non-CO2 components would tip things in the other direction, but I'd definitely welcome better numbers...

[1] https://www.faa.gov/regulations_policies/policy_guidance/env...

[2] https://en.wikipedia.org/wiki/Exhaust_gas#Spark-ignition_and...

[3] https://climatechangeconnection.org/emissions/co2-equivalent...

Oh wow, interesting. I was looking around and found another estimate that it's 1.4 tons (SFO/NYC round-trip).

I guess this is better (365% vs. 543%), but still looking much worse than driving?

[1] https://co2.myclimate.org/en/flight_calculators/new

I got about 1.3 tons for BOS<->SEA. Close enough I guess. For cars, start with

https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-t...

Look at the third answer down. The figures I cited earlier were based on about half that mileage per year, so that comes out to 2.3t. Lots of unit confusion here, but I think those both end up being metric tons and the daily commute is already worse than monthly air travel. Maybe that's all wrong, but the point I'm trying to focus on is that the need for regular long-distance travel severely erodes the environmental value of letting people work from home.

> that comes out to 2.3t

2.3t per year, not per month, though.

Ah, right you are. Now I'm really sad.

Okay, so to also summarize for anyone else reading, here's what's going on. The assumptions are:

- Using 261 gal gas/year (which 21.5 gal/month, or e.g. driving 2 × 15 mi/day at 41 mi/gal)

- 1 gal gas = 8.9kg CO₂ (resulting in 2.3 tons of CO₂/year)

In your case that's 15.6 tCO₂/year for flying, vs. 2.3 tCO₂/year for driving.

So, yeah... your flying footprint is 678% more than driving. i.e. you need to fly to work less often than once every 7 months in order for it to beat driving the route you had in mind.

Sorry for the bad news :( but yes, you're very much correct that this makes it even harder for remote work to be good, if you have to fly even twice a year.

> this makes it even harder for remote work to be good, if you have to fly even twice a year.

Well, he's working a continent away from his office. There are still infinite possibilities for remote work without having to travel 2500 miles for those occasional visits.