[jmyeet]

The land requirement for cows you refer to is probably the US-centric one. That's not universal. For example, Australian cattle pretty much roams arid land not suitable for crop production. The food is supplemented but still the carbon footprint of Australian cattle is very different to US cattle.

My main point is that if we ignore the tragedy of the commons of land use (which we do), the energy cost of growing a cow is largely free.

Lab grown meat requires probably a sterile environment and you'll be paying for that energy. Where is that energy coming from? What is the footprint of that? Now maybe that density of lab meat production is really high but I'd be surprised. Large herbivores can gain hundresd of pounds a year just grazing.

I do believe in the future of industrial farming. I just don't think it'll be meat. It's more likely automated greenhouses of likely hydroponics. It's entirely feasible that this way can easily support a trillion people on EArth [1].

[1]: https://www.youtube.com/watch?v=OzVxdmC8c-g