Does it take into account the farming and supply chain costs of that food it's about 15% efficiency by calorie, compared with gasoline which is close to 90% efficient IIRC. Or is it just food/fuel energy -> work?
Common gasoline engines have an efficiency around 30-40%, assuming modern high-efficiency designs. For older designs this is closer to 20%.
The lifecycle emissions of an EV depend on how the electricity was generated, and the total emissions of cycling depends on the diet of the cyclist - even though the energy per distance is the same regardless.
Yes, that might be true, but it's the "coal" that's the issue, not the recycling. It says so little useful about recycling that it's basically a lie. But it does suggest we should phase out coal, not just to make recycling cleaner, but for everyone that uses electricity.
Similarly, I assume this study looked at red-meat reared in a GHG callous manner. Which says basically nothing about bicycles, but does tell us that we should take the obvious steps we're already aware of to decarbonize food. Not because it helps cyclists be more efficient, but because it's a smart thing to do for everyone who eats.
> Indeed, the use of fertilizers, methane gas released from livestock like cattle and massive food waste all contribute to the vast carbon footprint of food production. Since land is both a source and a sink of CO2, land-clearing for new agricultural terrain in tandem with deforestation drives harmful emissions, equating to approximately 26% of the global total.
It doesn't count the manufacturing of each. It's still a valid comparison without it, cause most Americans who have a bike probably also have a car that they need for trips that aren't bike-able, and also cause it helps to separate fixed and marginal costs anyway.
They also picked a car that is twice as efficient as the average car for comparison and the most meat-heavy fiery possible (essentially meat only). That’s interesting as a though experiment, but not as a basis for policy- which is exactly what they state in their preface.
Also, you'll still need the roads for logistics.
My point about maintenance also still stands.