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> Are you intentionally clowning me here? Let's assume good faith on both sides, otherwise this discussion will go nowhere. Agreed? > They’re not the total bi

by esarbe 5y ago

> Are you intentionally clowning me here? Let's assume good faith on both sides, otherwise this discussion will go nowhere. Agreed? > They’re not the total biomass No, they're not. I never claimed that. My claim was that >> Of course fish and insects are part of the biomass. Anyway. That out of the way, let's have a look at > Just because a couple species types have declined by X%, It's not a couple of species. It's whole ecosystems that are being emptied. The Zoological Society of London report [0] monitors 4392 vertebrate species. There's a consistent and dramatic reduction. > This paper tries to measure the thing you claimed Thanks for the research and for taking it serious enough to do some data hunting. I'll happily dig into the report. Since it's from 2011, I wonder if there's an updated version that includes more recent data. I honestly don't have a better source that aggregates the loss globally over all species. I would be interested in more exact numbers. (Ask HN?!) >>>> but at least might not be off by orders of magnitude. I think we have established that the 75% is not "off by orders of magnitude". Could it be 60% reduction? Or 50%? Sure. Absent more data this could be possible, certainly. Given that it's only been a few decades, I don't think that matter too much - it's devastating in any case. But I think we can agree that it's definitively above 7.5% or 0.75%. I honestly think that 75% is not too far off. [0] https://www.zsl.org/sites/default/files/LPR%202020%20Full%20report.pdf https://www.zsl.org/sites/default/files/LPR%202020%20Full%20...

wyager 5y ago
> Let's assume good faith on both sides… I never claimed that. It’s hard to assume good faith when you keep saying nonsense and then acting like you didn’t. You said: > Since the middle of the 20th century, we've lost about 75% of biomass and roundabout the same in biodiversity. That’s obviously untrue, so now you’re acting like you were only talking about fish? > I think we have established that the 75% is not "off by orders of magnitude". Could it be 60% reduction? Or 50%? Sure. Did you notice that the 45% reduction was over five thousand years, not ~75 years as you claimed? Once again, you are saying totally whack stuff to the point where I have to assume you are trolling me somehow.
- esarbe 5y ago
  >> Since the middle of the 20th century, we've lost about 75% of biomass and roundabout the same in biodiversity. > That’s obviously untrue, I've provided quite a bit of material for your research. Here are some highlights: - birds: reduced by 29% (north america) since 1970 - birds: reduced by 20% (europe) since 1980 - ocean fishes: 80% lost in the last 100 years (global) - insects: 82% lost in the last 27 years (Europe) - freshwater fishes: 80% lost since 1970 - non-livestock mammals: 78% lost since 1960 I freely admit that the 75% since 1950 number is a ballpark guess. Given the data I refer to above, I reckon it's not far off. Certainly not orders of magnitude and it is certainly not "obviously untrue". We can debate if we lost 75% or 65% or 55%, but given the consequences in any case it doesn't really matter[0]. > so now you’re acting like you were only talking about fish? What? No. I'm talking about global, total biomass. Every species, every habitat. I'm sorry if that wasn't clear. (Why would you think that I was talking only about fish? Are you trolling me?) With regards to fish I wrote > The most visible I think it is for fish. There alone we've lost an approximate 80% since the 1950ies. To rephrase; the decline of fish is easily observed by the ever diminishing returns of fishery fleets and there's a lot of data about development of the fish population. > Did you notice that the 45% reduction was over five thousand years, not ~75 years as you claimed? That's one paper that makes some assumptions and comes up with a model. I have to check it in detail and it looks interesting. But that does not in any way refute the data in the papers I already provided or the very comprehensive report by ZSL[1]. This is a very thorough study that compiles data for 21,000 populations of animals from 4392 species. To quote: "The population sizes of mammals, birds, fish, amphibians and reptiles have seen an alarming average drop of 68% since 1970. > Once again, you are saying totally whack stuff to the point where I have to assume you are trolling me somehow. I'm sorry if you got that impression, because it's not my intention. I thought that I'd made a good case by quoting the research and various papers. I'm not sure why you say that this is "totally whack"; everything is sourced pretty well. [0] We're staring into the abyss and the abyss is winking back. [1] https://www.zsl.org/sites/default/files/LPR%202020%20Full%20report.pdf https://www.zsl.org/sites/default/files/LPR%202020%20Full%20...

by esarbe 5y ago

wyager 5y ago

> Let's assume good faith on both sides… I never claimed that. It’s hard to assume good faith when you keep saying nonsense and then acting like you didn’t. You said: > Since the middle of the 20th century, we've lost about 75% of biomass and roundabout the same in biodiversity. That’s obviously untrue, so now you’re acting like you were only talking about fish? > I think we have established that the 75% is not "off by orders of magnitude". Could it be 60% reduction? Or 50%? Sure. Did you notice that the 45% reduction was over five thousand years, not ~75 years as you claimed? Once again, you are saying totally whack stuff to the point where I have to assume you are trolling me somehow.

esarbe 5y ago
>> Since the middle of the 20th century, we've lost about 75% of biomass and roundabout the same in biodiversity. > That’s obviously untrue, I've provided quite a bit of material for your research. Here are some highlights: - birds: reduced by 29% (north america) since 1970 - birds: reduced by 20% (europe) since 1980 - ocean fishes: 80% lost in the last 100 years (global) - insects: 82% lost in the last 27 years (Europe) - freshwater fishes: 80% lost since 1970 - non-livestock mammals: 78% lost since 1960 I freely admit that the 75% since 1950 number is a ballpark guess. Given the data I refer to above, I reckon it's not far off. Certainly not orders of magnitude and it is certainly not "obviously untrue". We can debate if we lost 75% or 65% or 55%, but given the consequences in any case it doesn't really matter[0]. > so now you’re acting like you were only talking about fish? What? No. I'm talking about global, total biomass. Every species, every habitat. I'm sorry if that wasn't clear. (Why would you think that I was talking only about fish? Are you trolling me?) With regards to fish I wrote > The most visible I think it is for fish. There alone we've lost an approximate 80% since the 1950ies. To rephrase; the decline of fish is easily observed by the ever diminishing returns of fishery fleets and there's a lot of data about development of the fish population. > Did you notice that the 45% reduction was over five thousand years, not ~75 years as you claimed? That's one paper that makes some assumptions and comes up with a model. I have to check it in detail and it looks interesting. But that does not in any way refute the data in the papers I already provided or the very comprehensive report by ZSL[1]. This is a very thorough study that compiles data for 21,000 populations of animals from 4392 species. To quote: "The population sizes of mammals, birds, fish, amphibians and reptiles have seen an alarming average drop of 68% since 1970. > Once again, you are saying totally whack stuff to the point where I have to assume you are trolling me somehow. I'm sorry if you got that impression, because it's not my intention. I thought that I'd made a good case by quoting the research and various papers. I'm not sure why you say that this is "totally whack"; everything is sourced pretty well. [0] We're staring into the abyss and the abyss is winking back. [1] https://www.zsl.org/sites/default/files/LPR%202020%20Full%20report.pdf https://www.zsl.org/sites/default/files/LPR%202020%20Full%20...