Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Wild mammal biomass has declined by 85% since the rise of humans

ourworldindata.org

Post reply on HN
Print view View original

51–60 of 447 posts

Re: Wild mammal biomass has declined by 85% since the rise of humans

#51

Post by nicoburns »

JoeAltmaier wrote: post #27

You have any prepper ideas about surviving an apocalypse and living off the land, forget about meat. It'll be crickets or some such. All the wild meat in the world will be gone in like 4 days due to massive over-hunting.

I'd guess that depends greatly upon where you live. Some places are sparsely populated, and I suspect it's these rural people who would have the best chance of surviving in an apocalypse. The earth is a big place. There's a non-trivial chance that some people wouldn't be affected at all.

Re: Wild mammal biomass has declined by 85% since the rise of humans

#52

Post by JoeAltmaier »

nicoburns wrote: post #51
JoeAltmaier wrote: post #27

You have any prepper ideas about surviving an apocalypse and living off the land, forget about meat. It'll be crickets or some such. All the wild meat in the world will be gone in like 4 days due to massive over-hunting.

I'd guess that depends greatly upon where you live. Some places are sparsely populated, and I suspect it's these rural people who would have the best chance of surviving in an apocalypse. The earth is a big place. There's a non-trivial chance that some people wouldn't be affected at all.

There are a LOT of people. Even a small percentage remaining, would quickly deplete all available wildlife.

E.g. 1 deer will feed a family of four for a week. Or somewhere about that.

There are approximately 100 deer per square mile in the US midwest.

If population were depleted to a tiny fraction of what it is now, there could still be about one family per section.

They would deplete the deer population to zero in 2 years.

Re: Wild mammal biomass has declined by 85% since the rise of humans

#53

Post by doliveira »

club_tropical wrote: post #44
pvaldes wrote: post #13

Lets take in mind that there is a problem to compare two groups when one group is much easier to measure than the other. The error interval in the mammal biomass should be much higher. The actual real values are probably not so extreme. ... I see, is just megafauna. The most competitive groups (rodents and bats) are deliberately excluded. The title is incorrect then.

Also, “biomass” is a strange term. Is that literally an estimate of mass? Or count of individuals? Many other context lacking as well. This is clearly written for the 96% statistic shock, not to inform anyone.

Pretty sure that's the estimate of carbon content, but it's a proper scientific concept.

Re: Wild mammal biomass has declined by 85% since the rise of humans

#54

Post by myshpa »

https://ourworldindata.org/biodiversity

Wild mammals:

100.000 years ago ... 20 mil. tonnes of carbon

10.000 years ago ... 15 mil. tonnes of carbon

100 years ago ... 10 mil. tonnes of carbon

now ... 3 mil. tonnes of carbon

https://ourworldindata.org/mammals

"Wild mammal biomass has declined by 85% since the rise of human civilizations. This was mainly driven by overhunting and habitat loss."

"Wild animals only make up 4% of the world’s mammals; humans account for 34%, and our livestock for 62%."

"More than 178 of the world’s largest species went extinct during the Quaternary Extinction. Overhunting was likely the main driver."

"One-quarter of the world’s mammal species are threatened with extinction. Most are in the tropics."

"It is the largest mammals that are at the greatest risk of extinction. Most due to overhunting and poaching."

Cowspiracy [https://www.cowspiracy.com/facts]:

"Ten thousand years ago, 99% of biomass (i.e. zoomass) was wild animals. Today, humans and the animals that we raise as food make up 98% of the zoomass."

Postgrowth [https://medium.com/postgrowth/the-bomb-is-still-ticking-2810...]:

""Research by Professor Vaclav Smil from the University of Manitoba in Canada shows that as a percentage of mammalian zoomass, human beings and our domesticated mammalian animals (for food, beasts of burden and as pets) have gone from <0.1% 10,000 years ago, to 10–12% at the start of the industrial revolution to between 96–98% today."

Re: Wild mammal biomass has declined by 85% since the rise of humans

#55

Post by JumpCrisscross »

Retric wrote: post #42
giantg2 wrote: post #39

Earlier quoted context omitted.

"Every single tonne of steel manufactured by humans from prehistory until about a century ago -- the entire output of the industrial revolution -- amounts to less than one year at current production." The real questions are: Does that include recycling? If not, how do we see this being sustainable?

Walk around and pick up a random rock. On average it’s 5% iron which combined with just a little carbon makes steel, so no we aren’t running out. This is also why the Iron Age was such a big deal. The bronze age required both copper and tin which where rare and didn’t generally show up near each other while you could operate a shitty iron mine just about anywhere.

Is there a reason the Bronze Age had to precede the Iron Age? At least in the Mediterranean, the only continuous civilisation I’m aware of was Egypt.

Re: Wild mammal biomass has declined by 85% since the rise of humans

#56

Post by freedude »

docmechanic wrote: post #2

This statistic always takes the top of my head right off: "The dominance of humans today is clear: us and our livestock account for 96% of global mammal biomass. Wild land mammals make up just 2%." If you, like me, wondered about poultry ... "Here we focus on mammal populations, so neither wild birds or poultry are included. But for birds the story is similar: our poultry biomass is more than twice that of wild birds…

Good point about birds. Add them to amphibians, fish and insects and it would make this look less impressive.

Re: Wild mammal biomass has declined by 85% since the rise of humans

#57

Post by akiselev »

giantg2 wrote: post #39
retrac wrote: post #25

Going off on a tangent, but the scale of production is very hard to grasp. I'm probably not the first person to observe this, but I once did some napkin math about steel production, and what I realized kind of blew me away. About 1.9 billion tonnes in 2020. Like with billions of dollars, I have no intuition for such numbers. Context is needed. Global steel production just before WW I was about 70 million tonnes. So p…

"Every single tonne of steel manufactured by humans from prehistory until about a century ago -- the entire output of the industrial revolution -- amounts to less than one year at current production." The real questions are: Does that include recycling? If not, how do we see this being sustainable?

Yes, it does. About 40% of steel produced globally is recycled and the number for some other metals like aluminum are even higher. IIRC almost 80% of steel production in the US is from recycled stock.

Processing ore is very energy intensive. Problem is the world needs a lot of steel

Re: Wild mammal biomass has declined by 85% since the rise of humans

#59

Post by myshpa »

The sad thing is that 100 years ago humans and livestock accounted for around 5% of the biomass (all zoomass, not land mammals only), 95% being the wildlife. Now the numbers are reversed.

We've stolen the land from the wildlife and dedicated it to a few species we consider edible (agriland is more than forests now, and 75% of it for animal agriculture).

Is anybody surprised that we're living in the anthropocene, defined by massive die off of wild species?

We have to (as a species) return the land to wildlife and let it repopulate the earth, otherwise we'll lose them. We don't even know what gems we're losing. I'm not talking about some bugs, but about dna - those are millions of years of (computer) code generated by nature, code so precious we don't even have an idea how to simulate it, let alone understand it (at this point in our evolution).

If we lose it, goodbye new medicines, new regenerative dna techniques, new technologies, and who knows what. We simply cannot know what we're stealing from future humans (this point was made for the selfish humans we are, better arguments could be made).

Re: Wild mammal biomass has declined by 85% since the rise of humans

#60

Post by nicoburns »

JoeAltmaier wrote: post #52
nicoburns wrote: post #51

Earlier quoted context omitted.

I'd guess that depends greatly upon where you live. Some places are sparsely populated, and I suspect it's these rural people who would have the best chance of surviving in an apocalypse. The earth is a big place. There's a non-trivial chance that some people wouldn't be affected at all.

There are a LOT of people. Even a small percentage remaining, would quickly deplete all available wildlife. E.g. 1 deer will feed a family of four for a week. Or somewhere about that. There are approximately 100 deer per square mile in the US midwest. If population were depleted to a tiny fraction of what it is now, there could still be about one family per section. They would deplete the deer population to zero in 2…

There are a lot of people. But not everywhere. What you say will true for the US. But in more sparsely populated and less accessible parts of the world it may not be.
Post reply on HN