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Comment by nerdponx | Hacker News Reader

> the amount of grazing required for that is absolutely larger than anything we have today

Who's to say that there wasn't more grazing (by area) back then?

> Further, grazing makes fields more robust if done property.

I'm not a farmer, but I know that this depends a lot on what is doing the grazing. Sheep for example apparently graze the grass down really far, and prevent the growth of bushes and tree saplings that are otherwise important for balancing the ecosystem.

In the US in the 1800s, there was outright armed conflict between sheep and cattle ranchers over this issue: https://en.m.wikipedia.org/wiki/Sheep_Wars

And as far as I know, England and Scotland lack trees specifically because overgrazing prevented forests from regenerating after being cut for timber: https://youtu.be/nAGHUkby2Is

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One reason cited for lack of new sequoia growth in the Sierra Nevada is introduction of sheep towards the later period of Spanish colonization, and continued through early 1900s with the US taking over.

You need people to herd animals. There weren’t nearly the same number of people back then. The people who were around would have been largely nomadic especially if they were herding animals since they would need to move their herds to different grazing land depending on the season. Those aren’t conditions that create overgrazing which occurs when you have a lot of people with a lot of animals using limited pasture land that’s broken up by property lines and agriculture.

I would need to see a source for this, because it doesn't sound plausible to me. Populations were lower of course, but look at how much of the population is concentrated in city centers today.

I would hardly be surprised if rural population density was significantly higher than in the past, with more farms as well as more grazing herds, even if they were much smaller than what we have today.

But I also don't really know if this squares with the sheer amount of meat and dairy that modern humans consume. How much does factory farming offset the need for open grazing land?

Basically, this is a subject area where intelligent clever people get themselves into trouble by thinking they know more than they do. I'd rather see what the experts say.

You’d be surprised how small the human population was. Estimates for 1 AD are somewhere between 150 and 300 million people in the entire world. Our historical impact on the surface of the earth is tiny compared to what we do now but even our modern efforts are often lost within the sheer vastness of the earth. The world 5000 years ago was mostly devoid of human life.

That is assumption backed by the most patchy evidence. The fact is that we have no idea what population was in the absence of major construction or seashell middens left behind, in almost all places.

Recent decades have seen population estimates forced to be raised by orders of magnitude in many places.

They were still small especially compared to everything within the last 150 years. You’re going to have to back up your claims if you are going to propose a much higher number.

Which part of "The fact is that we have no idea what population was" are you having trouble with?

Actually, this is not the real problem. It's not the herding of animals that's creates the overgrazing. It's the large scale killing of predators. This creates huge herds of grazers that absolutely destroy the landscape. This is how the savannah and the great plains where created. To protect their herd and children; natives killed the lions, saber tooths, wolves, hyenas, big cats and bears. In effect creating the great grassy plains. Not saying that humans created all the large grassy plains; just saying they have become substantially bigger since humans are around.

That is an assumption.

It did not happen in Africa.

In North America, megafauna (dire wolf, saber-tooth cat, cheetah, horse, camel, mammoth, mastodon, giant sloth, 30+ genera) were killed off not by human activity but by a comet strike c.10818 BCE. It did in the Clovis culture, too. There were simultaneous extinctions in South America and Africa.

In fact we have almost no idea what the human population was, in most areas of the world. And, none at all in the millions of square miles of the Sunda region, now under water from Java to Viet Nam, and connected to more land where the entirety of the South China Sea and Yellow Sea now are.

For many decades anthropologists and archaeologists earnestly insisted the Americas were barely populated, pre-Columbus. Now we have found major earthworks projects in both North and South America that required societies in, at minimum, tens of millions to have built and maintained.

We know appallingly little about the recent history of our species beyond ~6000 ya, with only tiny, isolated digs at older sites.

A major earthwork in Java, Gunung Padang (previously assumed to be a natural feature because of it size), dated to 22 kya has had excavations halted since 2014.

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