I hate to be that guy, but this is true. Before you pull out your pitchforks, read this explanation.

I take a bicycle to essentially all of my local errands, so I thought it would be cool to write an app that calculates how much CO2 emissions you've saved based on the number of errands you've run by bike (by distance). I wanted to consider everything, like food intake, emissions associated with manufacturing, etc. To be clear, the exact emissions varies wildly depending on what numbers you plug in, but it almost always comes out in favor of a passenger car. This only considers CO2 emissions, and ignores noise pollution, microplastics, and other potential environmental issues.

Long story short, if the following things are true, you'll probably release less CO2 by taking a car:

• You drive a reasonably efficient car (30 mpg+)
• You drive your cars for a long time (150,000+ miles)
• You get most of your food from the grocery store (not local, like a farmers market)
• You are not vegan

These assumptions do make quite a few concessions, but I think it's fair to say the majority of Americans fit these criteria.

In order of CO2 emissions per mile using the same assumptions as above (lowest to highest):

• E-bike
• E-scooter
• Bus (divided across all passengers)
• Gas passenger car
• Electric passenger car (again, considering manufacturing, ~150k miles of ownership)
• Bicycle
• Truck
• Walking

This is not me suggesting cars are better for the environment overall, but it's an uncomfortable fact that humans are wildly inefficient at converting chemical energy into kinetic energy. Just think about the fact that when you burn 1000 extra calories per day, a significant portion of those calories had to be driven hundreds of miles on a diesel truck after spending months/years being grown on a farm.

Here's the factors I considered. Let me know if you can think of anything I missed and I'll re-run the numbers:

• Calories above baseline for driving/cycling, and the associated food production
• Emissions associated with use (tailpipe emissions, cyclist exhaling)
• Emissions associated with manufacturing
• Emissions associated with maintenance

Here's some things I did not consider:

• Emissions associated with building/maintaining infrastructure
• Emissions associated with car dependency sprawl (i.e. everything is farther apart to accommodate cars)
• Proximity of air pollution (cycling has practically zero air pollution locally, which is good for cities)
• Tire microplastics, disposing of vehicle parts, etc.
• The benefits for the environment, healthcare, and public resources associated with reduced obesity from cycling
• The increased tendency to shop locally with improved micro-mobility from walkable/bikeable cities

I guess the moral of the story is that being vegetarian is significantly more impactful than cycling to work (I say as a non-vegetarian cyclist).