Mildly Interesting

Speak for yourself, I bike with a bag on my head to capture my emissions.

bike pollution is slightly more than nil just because of the CO2 we breathe out while riding

Technically, the CO2 animals exhale is carbon neutral because it's from plants you eat (or your food eats). Unless you're eating petroleum derived products of course.

I say technically because while the plants themselves are carbon neutral, modern food production and distribution, especially meat production, still has a large carbon footprint. So your breath is only truly carbon neutral if you foraged for food in the forest on foot.

Don't forget that many small propeller driven aircraft run on leaded gas, and it's a formulation of leaded gas that has 10x the lead that motor fuel used to.

I gave up flying to have kids. Probably worse for pollution

as if rich people care about how much they pollute

But, do that people have light aircrafts or motherfucking Boeings 787?

Walking pollution: ...

That's right, bike pollution is less than walking (or running) pollution in terms of CO2 per mile travelled. Cycling typically burns ~⅓ of the calories compared to making the same journey on foot and there's a direct link between calories burnt and CO2 produced.

Cycling at 12mph takes roughly the same energy as walking at 4mph. You emit the same CO2 per minute, but get there in ⅓ of the time. Running at 12mph takes 3 times the effort of cycling at 12mph. You'll get there in the same amount of time, but breath out 3 times as much CO2. Bicycles are more efficient than our own two legs - how cool is that!

I feel like it should be .. for the amount of gas I release while cycling.

Plane pollution is not that much worse than a car. Depending on what metric you measure it can be better (planes are more fuel efficient and thus less CO2. Small planes like the picture generally use lead fuel and old engine designs that pollute more) on long trips.