"Big Carb" is what allowed human population to grow to billions.

Okay, and you can argue we were naturally never supposed to be in the billions. You can argue if global warming wipes out our farms, we can only blame ourselves, and demographic crashes are a given, not a crysis.

I'm not particularly religious, so I don't know about "supposed to be", but I see no ethical way of significantly reducing human population quickly enough for it to matter for climate change. It is much easier to change our behavior to reduce environmental impact. Switching everyone to a carnivore diet to spite "Big Carb" is certainly not the right direction.

I'm not suggesting a change in diet at all, I'll continue to be omnivore as will my kids. This will lead to catastrophe but that's life.

There were two billion humans on the planet before "big carb". People used to eat things like butter without fear of cholesterol and they didn't even suffer the heart attacks that avoiding cholesterol was supposed to prevent.

Humans have been getting most of their calories from grains essentially since we invented agriculture, thousands of years before the population reached even one billion.

What's "Big Carb"? Even everything you've derided as "experimental food" is mainly fats and proteins, not carbohydrates?

I gave an example of experimental foods being pushed as cheap substitutes for the real thing, and how quickly society accepted them. I'm postulating that's what's happening with the trend of veganism.