Live data from Hacker News

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

ourworldindata.org

21–30 of 447 posts

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

#21
post #8

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…

Reminds me of the matrix. Agent smith said it so well. https://www.youtube.com/watch?v=mgS1Lwr8gq8

Or perhaps Agent Smith mistook an S-curve that hasn't started to level off yet for unfettered exponential growth.

> Generally, developed nations have seen a decline in their growth rates in recent decades

(https://en.wikipedia.org/wiki/Population_growth#Population_g...)

Or perhaps he was just evil and had a hatred of humanity that he was justifying with whatever reason pleased him.

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

#22
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.

Certainly the article might not be credible, but can you cite the relevant text from the article, so that the rest of us can quickly verify your claim? I'm not seeing where in the article this is stated.

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

#23
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.

Is this true? This source (https://www.pnas.org/doi/10.1073/pnas.1711842115) gives a very similar percentage (95.8% of all wild mammals) and doesn't mention anything about excluding rodents or bats from the categorization of wild mammals. Is it in a footnote somewhere that I'm missing?

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

#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 production has increased about thirty-fold in one century. That wasn't so shocking to me, at first. But 1910 was not the beginning of the industrial era; things had been under way for more than a century then. Railroads. Ocean liners. Factories. Knives and rivets for fabric owned by hundreds of millions of people. Dozens of skyscrapers in New York by then; the Brooklyn Bridge hung on thousands of tonnes of cable. All made out of steel.

Then it struck me. A few million tonnes a year in 1850. 70 million tonnes in 1910. All of it adds up to less than 1900 million tonnes. 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.

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

#29
I can't be the only one who is extremely tired of these semi-frequent utterly nihilistic "I'm sad to be part of the human species, we're killing the planet" posts and comments, especially when the posts themselves are possibly misleading (whales aren't included? come on). I don't know about you but I'm quite happy to be alive and reasonably healthy, and I hope to have many children, I hope mankind doesn't go extinct anytime soon, and I'm not going to eat any bugs or fake meat or any of that.

nihilistic platitudes like "how is there still an ecosystem?" are completely baffling to me—I don't understand what would make someone think that way. what could have caused this level of innate shame felt on behalf of one's species?

the only thing I can think of is that people overestimate the power of mankind and underestimate the power of nature possibly due to living in dense urban environments surrounded by nothing but artificial creations of man all day every day, and this skews their perspective.

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

#30
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…

Wow! Probably similar numbers for concrete. It's exponential growth.

The thing about exponential growth is it can't continue for too long. As observers of Moore's Law will understand, eventually you run out of resources or into other physical limits.

However, I'm quite confident that we can keep innovating and growth will continue in one form or another. I don't think Elon Musk is correct that human population will collapse. All it takes is one subgroup to keep reproducing above the replacement rate, and after enough generations they will come to dominate and overall growth will continue. It's pretty much the law of life - expand to consume all available resources, be that food, space, energy, oxygen, whatever. You see it in bacteria, in fish, in mammals large and small, and of course in humans.

There will be lot's of challenges there, and lots of need for innovation so we can handle growth without destroying our remaining wild spaces and ecosystems on which we depend. Humans haven't figured out how to grow sustainably yet.

Post reply on HN