No, it's not sustainable. But that's because we are too many humans in this planet, more than what this planet can naturally sustain. In other words, it's US who aren't sustainable, not the Paleo diet.

We'll soon be able to "replicate" food via food synthesizer, so don't worry about it. "Beam me up some steak, bro"! Oh, wait, no, I'm still waiting for my frakken hoverboard...

Unsustainable? I don't think so. Maybe the meat-centric, one-size-fits-all version is. But take a paleo diet based upon what can be grown locally and sustainably. A sustainable paleo diet in the American midwest is going to be very different than a paleo diet in equatorial Africa or a paleo diet in Japan. Just because the whole world won't be able to gorge on beef and coconut oil, doesn't make it unsustainable.

Personally, I would email Joel Salatin. He's the only person you mentioned who actually farms. He speaks on this topic, among others.

The arguments are meaningless. We need real food. If no one else makes real food, I will try to make it myself, for myself and my loved ones. This is the human level view. The sustainability arguments tend to get lost in a faux god's eye view. Sometimes we can tell something isn't sustainable, like the stupidity of putting bees on trucks and driving them up and down California- of course they are dying! But often, the sustainable argument is made by someone blithely assuming they are omniscient and powerful enough to make global level decisions. Just as fancy, multi-variant computer models lead to bad science, this sort of arrogance leads to bad policy.

I think it can be done.

Will it be done? Not likely.

It would take radical change along several high-impact powers that be. In the US alone, you would have the USDA, the food lobbies, the land developers, the subsidies, etc... that are concerned with a solution that provides more food - cheaper, not more food - better. They will latch onto Government recommendations for food, and the Government's recommendations for food always follows the science of the lobbies.

The Locavore movement, even with it's oft-hated hipster majority, is part of the resistance.

Sustainability Farming such as Polyface - is part of the resistance (we just need a few more highly visible farms than one in Rural Virginia to make it appear viable to the masses).

Many celeb chefs have been stressing local, fresh - and to that end, Farmer's Markets have been springing up. Some of them are pretty lame, with 1-2 actual farms represented and the rest a mis-mash of shit you'd find at a fair or gun show (you listening, Saint Petersburg Farmer's Market?) - but it's still a step in the right direction.

So yeah, we need more than yuppies, hipsters, and hippies seeking out local food. The world can find a solution (although frankly, the world is overpopulated - as Eugenia said, it's a problem of humanity - not of any particular diet or way to eat).

The most honest answer might be that we simply don't know. There are an awful lot of variables when you're talking about billions of people and tens of billions of acres. For a long time, soil has been looked at as fairly static: you have a certain amount of clay, sand, etc., plus N, P, and K, and that produces a certain amount of food. If you want more food, you add more nutrients. But we're learning all the time about the significance of microbes in the soil, and we're just starting to understand the symbiotic relationship between animals and soil and how much the soil benefits from animals grazing on it. It's a lot more complex than, "cow eats grass and leaves behind manure which grows more grass," but we're just starting to get back to that much understanding.

There are also political complications. Large areas of formerly productive land have been turned to deserts by poor farming practices. The stereotype is of the poor goat farmer letting his animals wipe out all the vegetation, which has been used as another black mark against meat, but desertification is also caused by irrigation lowering the water table and leaching away nutrients and quality soil from the surface. Over-cultivation of row crops increases soil runoff and loss to wind. Whatever the many reasons, how do you go into numerous countries and tell people they have to give up the farming practices that are barely keeping them alive as it is? They don't have the luxury of worrying about whether their land will still be productive in 50 years; they're trying to get a meal right now. Unless you posit some sort of one-world benevolent Star Trek-style government, much land has to be considered unavailable for sustainable production in the near term.

As someone else said, it depends on what people are willing to eat. If 'paleo' means buying specialty oils and other items shipped halfway around the world, that may not be very sustainable. The globalist, corporate farming paradigm pushes the same few monocultures for everyone, as that's the most efficient and profitable model for the corporations and governments that run things. But if it means growing animals and plants that are suited to your local conditions, it may be possible to grow a lot more. But that's not something that can be organized on a global scale by large, top-down NGOs; people just have to do it (and have the freedom and property rights to do it).

Yes to the lifestyle. Hunt-and-gather is the most important part. In terms of what it does for lowering stress, CV health and stabilizing metabolism it's the cure for the greatest Neolithic disease Sedentism. It can be practiced anywhere and the cost is measured in shoes.

I don't consider the diet as sustainable as the lifestyle. I worry about the loss of meat for multiple reasons, both political and economic.

Who cares if it's sustainable? The bottom line is I'm going to buy the best food for me that is within my budget, and I hope everyone else does to. If that means that farms and corporations start to produce more nutritious healthier food, I'm sure they'll find the most efficient way to go about it. Just because we aren't sure it's sustainable or not doesn't mean everyone should eat poison. That's stupid!