A new study shows that if you aren’t ready to go vegan to save the world, then you should quit riding your bike and take a car.

An article in the Journal of Insufferable Busybodies (official title: Sustainable Production and Consumption) calculates the carbon footprint for a variety of sandwiches. These carbon footprints include carbon dioxide emissions from things such as farming, transportation, and refrigeration.

In the article, researchers at the University of Manchester offer helpful tips on Earth-friendly sandwich making. Among them: Avoid using lettuce, tomatoes, cheese, and meat.

If you’re like me, though, every sandwich you’ve eaten since middle school includes at least two of those ingredients.

However, don’t despair, you still can alter your behavior to reduce your carbon footprint. In particular, make sure you don’t ride a bike when you could drive a car.

How’s that? Well, the people at Phyics.org thought the sandwich-climate topic was important enough to get access to the full text of the original article.

They pass on this particularly interesting tidbit: A bacon, sausage, and egg sandwich (the whole Hampton Inn breakfast buffet in one tidy package) has a carbon footprint “equivalent to CO2 emissions from driving a car for 12 miles.”

Driving a car uses energy that comes from gasoline. Riding a bike uses energy that comes from the bicyclist’s food. Both sources of energy have carbon footprints.

We are told CO2 emissions from the life-cycle process of producing a sandwich is equal to that of driving a car 12 miles. The question, then, is how far will the calories in that sandwich take you on a bike?

It isn’t clear that anybody in the U.S. has the courage to sell the cardiologist’s delight described above, which means the total caloric content of the sandwich doesn’t show up on the first page of a Google search. Fortunately, my calorie-counting app (no evidence of use since 2015, hmm …) can do the job:

According to this calculator, a 180-pound bicycle rider going 15 mph for 51 minutes will travel 11.9 miles, but expend 729 calories.  So, this bacon, sausage, and egg sandwich doesn’t have enough food energy to power the cyclist for the full 12 miles.

The bicyclist would need to eat 1.3 sandwiches to go 12 miles. That is, the CO2 footprint of riding a sandwich-fueled bike would be 30 percent higher than driving a car.

Since it takes more energy to move bigger people, the imperative to drive instead of ride is even greater for those who shop in the Big & Tall section.

A 222-pound blogger, for instance, would burn 899 calories for the same time and distance, requiring 60 percent more sandwich and, therefore, 60 percent more CO2 from riding a bike than driving a car.

Of course, smaller people need less energy to propel themselves on a bike. The break-even weight for the ride-or-drive decision is around 140 pounds. Going more slowly helps, too.

If CO2-induced climate change is the existential threat some claim, and if people are still going to eat sandwiches that might include sausage, bacon, egg, tomato, lettuce, meat, or cheese, perhaps we need a prohibition against bike riding. Just sayin’.