4 ms·

Then came the first instance of catastrophic human steered overgrazing

by singularity2001 4y ago

lettergram 4y ago
That’s not true at all lol, complete BS. For one, the amount of grazing required for that is absolutely larger than anything we have today. We exited an ice age, which created conditions which helped to create pastures. Climate change has been happening far longer than humans have impacted it (not saying humans aren’t impacting it). Further, grazing makes fields more robust if done property. Grasses will grow faster to compensate and the poop enhances the conditions to create fields.
- deleted 4y ago
  [deleted]
- nerdponx 4y ago
  > 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 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 https://youtu.be/nAGHUkby2Is
  - towaway15463 4y ago
    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.
    - nerdponx 4y ago
      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.
      - towaway15463 4y ago
        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.
        ncmncm 4y ago
        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.
        towaway15463 4y ago
        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.
        ncmncm 4y ago
  - gpapilion 4y ago
    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.
nerdponx 4y ago
How much desertification in Africa is caused by humans? My impression has been that the Sahara, North Africa, the Middle East, and eastern Mediterranean were all gradually becoming dryer anyway. Is that wrong?
- juunpp 4y ago
  Yes, that was my understanding too. I don't have a solid ref for this now, but as far as I can tell, the entry here should be relatively accurate: https://en.wikipedia.org/wiki/African_humid_period https://en.wikipedia.org/wiki/African_humid_period It is true that the Holocene extinction and other events are caused by humans, and that, in the larger scheme of things, life on Earth would thrive better without us. But it is a fallacy to pretend everything is caused by us, and such claims only make conversations about real change caused by us more muddy than they need to be. At any rate, don't take "facts" from a magazine.
ch4s3 4y ago
All of the comments supporting this are by people who have failed to so much as google this topic. The Sahara used to get monsoon rains until about 11kya to 5kya[1] when the axis of the earth shifted a bit. [1] https://www.smithsonianmag.com/science-nature/what-really-turned-sahara-desert-green-oasis-wasteland-180962668/ https://www.smithsonianmag.com/science-nature/what-really-tu...

Then came the first instance of catastrophic human steered overgrazing

That’s not true at all lol, complete BS. For one, the amount of grazing required for that is absolutely larger than anything we have today. We exited an ice age, which created conditions which helped to create pastures. Climate change has been happening far longer than humans have impacted it (not saying humans aren’t impacting it). Further, grazing makes fields more robust if done property. Grasses will grow faster to compensate and the poop enhances the conditions to create fields.

deleted 4y ago
[deleted]
nerdponx 4y ago
> 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 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 https://youtu.be/nAGHUkby2Is
- towaway15463 4y ago
  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.
  - nerdponx 4y ago
    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.
    - towaway15463 4y ago
      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.
      - ncmncm 4y ago
        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.
        towaway15463 4y ago
        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.
        ncmncm 4y ago
- gpapilion 4y ago
  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.

nerdponx 4y ago

How much desertification in Africa is caused by humans? My impression has been that the Sahara, North Africa, the Middle East, and eastern Mediterranean were all gradually becoming dryer anyway. Is that wrong?

juunpp 4y ago
Yes, that was my understanding too. I don't have a solid ref for this now, but as far as I can tell, the entry here should be relatively accurate: https://en.wikipedia.org/wiki/African_humid_period https://en.wikipedia.org/wiki/African_humid_period It is true that the Holocene extinction and other events are caused by humans, and that, in the larger scheme of things, life on Earth would thrive better without us. But it is a fallacy to pretend everything is caused by us, and such claims only make conversations about real change caused by us more muddy than they need to be. At any rate, don't take "facts" from a magazine.

ch4s3 4y ago

All of the comments supporting this are by people who have failed to so much as google this topic. The Sahara used to get monsoon rains until about 11kya to 5kya[1] when the axis of the earth shifted a bit. [1] https://www.smithsonianmag.com/science-nature/what-really-turned-sahara-desert-green-oasis-wasteland-180962668/ https://www.smithsonianmag.com/science-nature/what-really-tu...