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

ourworldindata.org

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

#111

Post by epicureanideal »

patrec wrote: post #98
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…

So modern civilization currently requires the average human to consume roughly 3-4 times his body weight in steel per year. And given that steel production has roughly doubled in the last 20 years, this will probably still go up a fair deal.

If population levels off I would imagine the need for steel would mostly level off also?

I assume the main use is in construction?

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

#112

Post by myshpa »

jonnycomputer wrote: post #104
myshpa wrote: post #54

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…

Has total biomass (not just wild biomass) declined? I would expect it has, because most modern farming tries very hard to make sure the only thing growing is the thing that makes the farmer profit. A lot of farms are ecological wastelands; or rather, they sustain less biomass than they could.

I suppose it has. Farm land has 2% of a forest biomass (iirc). Agriculture (meat/dairy/sea-food) is worse than most want to acknowledge.

Land and marine ecosystems are decimated (70-90% die off, incl. soil & plankton). We've killed off almost everything.

The change has to come, there is nothing more important imho, or we'll be heading directly into blade-runner like future. Personally I would prefer star trek.

[thinking about internet minus points]

Learn to cook vegan, people ;)

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

#113

Post by [deleted] »

adamrezich wrote: post #97
agalunar wrote: post #83

Earlier quoted context omitted.

> I don't know about you but I'm quite happy to be alive and reasonably healthy I think the important thing to contemplate is that this might be at the expense of other people, living or yet to be born. Not that we've done anything wrong – just that the circumstances that make this possible for us might preclude it for others. > nihilistic platitudes like "how is there still an ecosystem?" are completely baffling to…

> I think the important thing to contemplate is that [being happy to be alive and reasonably healthy] might be at the expense of other people, living or yet to be born. Not that we've done anything wrong – just that the circumstances that make this possible for us might preclude it for others this is called the natural order of things. nature is competition. this is all self-evident. all of our ancestors innately und…

[deleted]

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

#114

Post by club_tropical »

jonnycomputer wrote: post #101
club_tropical wrote: post #44

Earlier quoted context omitted.

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.

Biomass is probably exactly the right measure, when we are talking ecology. A lot of mice to weigh up to one cow, it is true, but then, you could feed a lot of mice on the grain with which you feed your cow.

I understand that each animal group has a different weight range and that, if you reduce animal groups to “total weight” metric, you can compare cows with mice on that metric.

I do not agree that this is some kind of meaningful unit, especially in percentage terms, for anything that ecologists might be interested in, like population health, or whatever else.

The fact that ecologists think in terms of biomass while putting on a lab coat and getting a PhD does not make this metric make more sense.

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

#115

Post by pvaldes »

club_tropical wrote: post #105
pvaldes wrote: post #73

Earlier quoted context omitted.

Biomass is the whole mass of life beings, a standard and common measure that represents the energy contained in a particular group. Talking in terms of biomass is very common in Ecology.

I think it is an unclear and bizarre term. “The energy contained in one group” - what energy? Is a lean cheetah “less-energy” than an elephant? Why? Or do you literally mean energy like calories (which, IIRC means “how much heat if burned”). What a bizarre metric, nobody thinks like this, I don’t even think “ecologists” understand why they should think in terms of mass. I, too, can have a metric: number of decibels o…

> “The energy contained in one group” - what energy?

The chemical energy contained in the links of the molecules

> Is a lean cheetah “less-energy” than an elephant?

Yes, of course. One cheetah, has less biomass than one elephant. But -the- rats, have more biomass than -the- elephants. Is the beauty of the ecology.

> What a bizarre metric, nobody thinks like this, I don’t even think “ecologists” understand why they should think in terms of mass.

Well, this sounds a little arrogant. The professionals that use it, obviously, know their job. They aren't stupid.

Would be like claiming that programmers don't understand why they use an if loop. Biomass is a measure as widespread in ecology as Megabytes is in computers.

And there is not need to use quotes around the word ecologists, in the same way as you wouldn't wrote: the "engineers" or the "programmers".

> I, too, can have a metric: number of decibels of sound you can produce; maybe humans make up a SHOCKING 3% on that- doesn’t mean it’s a sensible metric.

Well, the difference is that nobody uses your metric.

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

#116

Post by jvm___ »

slashdev wrote: post #30
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…

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 c…

This is from a 2014 Forbes article.

"According to his blog, between 2011 and 2013, China consumed 6.6 gigatons of concrete – that’s more than the U.S. used in the entire 20th century. Look at what the U.S. built between 1901 and 2000: all those skyscrapers, the Interstate, the Hoover Dam, the list goes on and on but all that concrete only amounted to 4.5 gigatons."

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

#117

Post by club_tropical »

doliveira wrote: post #53
club_tropical wrote: post #44

Earlier quoted context omitted.

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.

The number of decibels they can produce is a “proper scientific concept”- metrics can be arbitrary and useless.

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

#118

Post by mrosett »

AtlasBarfed wrote: post #36
deathanatos wrote: post #21

Earlier quoted context omitted.

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.

But has their resource consumption per capita leveled off? Population numbers aren't the scary thing about our CURRENT population. What's scary is that China and India, which is almost 3 billion people, want US-levels of resource consumption, and they are full steam ahead in doing so. Oh, so the curve will tail off around 11 or 15 billion? Who cares. Each billion is 3x the population of the US, and they all want our…

> But has their resource consumption per capita leveled off?

Largely yes:

https://www.sciencedirect.com/topics/engineering/demateriali...

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

#120

Post by _-david-_ »

chinchilla2020 wrote: post #50
adamrezich wrote: post #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…

It isn't a skewed perspective. Our civilization passed the carrying capacity of the planet half a century ago. Resources are being consumed at a far greater rate, despite advances in technology. You don't need to be depressed or nihilistic about it. You can still live a great life and so can your children. The reality is that we need to start reducing consumption over the long term to prepare for the inevitable. Bein…

>Our civilization passed the carrying capacity of the planet half a century ago.

Can you provide some evidence of this?

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