lol all good - I posted some napkin math above - https://lemmy.ca/comment/7747680

Long story short this figure is just all around bad because it's conflating energy efficiency with environmental friendliness.

Electric vehicles, despite being greener, are probably less efficient (which is why ICEs are mysteriously absent from this figure), it takes a lot more watts of power to move a 5000 pound car than it does a 2000 pound one). Similar story with biking - based on my Garmin figures, biking is about 22x more energy efficient than driving an ICE car, but the carbon footprint of that energy source is much higher watt-for-watt, so if you eat a meat heavy diet, the bike is barely greener than driving (caveat: I didn't amortize the footprint of constructing the car, which is a probably a huge deal - if cycling is actually an option for you, your mileage probably isn't that high).

Granted - you are spot on with oats, if you pick a greener crop like corn you are down to 0.5kg carbon per 1L of gasoline equivalent - as the guy below wrote, biking is a "greener choice" if you are vegan (3-6x less carbon footprint), but at the end of the day, manual transportation is a thing people choose for health or pleasure reasons, or when the distance is so low that other methods don't make sense. if you are going to try and shame people into doing it out of a sense of environmental responsibility, you shouldn't need to use dubious math to accomplish that end