6 ms·

It's amazing to think of how alien the Earth has been in the past. I think we humans tend to fall victim to this idea that the world we first experienced is how

by cletus 5y ago

It's amazing to think of how alien the Earth has been in the past. I think we humans tend to fall victim to this idea that the world we first experienced is how things "are" or "should be" when in reality there's no baseline at all. The EArth has been frozen to the equator (~500M years ago). Sea levels have been higher. They've also been significantly lower and quite recently too (eg there are Neolithic artifacts in the English Channel because that was a land bridge 10-50,000 years ago). My favourite example: for the first 60M years of trees existing, there were no organisms to digest the wood of dead trees. They just sat there or maybe burned. This is where 95% of the coal comes from. I'd really give anything to see some of these periods all the way back to the Cambrian Explosion, which had some truly alien-looking life based on fossil records. It's also why I'm skeptical about doom and gloom predictions of runaway climate change. To be clear, I'm a firm believer that human activity has played and will continue to play a huge part in climate change. This also may be really bad for us. But the Earth will (ultimately) be fine. Something like 99% of the species that have ever existed are extinct now and this will continue to happen with or without human involvement. The article points out that DNA degrades quickly (~500 year half life). That doesn't mean it can't survive for millions of years. It just means very little of it does. Also environmental factors come into play (eg it would probably survive longer in Antarctica, for example). Still, recovering a complete genome from such fragments is all but impossible (also mentioned). Anyway, It's kind of amazing to think that a mosquito bit some creature ~46M years ago and a fossil of it somehow survived until today.

deleted 5y ago
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ahevia 5y ago
While you correctly pointed out that human activity is contributing to climate change. You forgot to mention how unprecedented the rate at which the climate is changing. A process that normally takes tens of thousands of years is happening within a 3-4 human lifetimes. Far too quickly for organisms to adapt. “Doom & gloom” is a defined differently to many people. What exactly do you mean here? Are humans going extinct & Earth is going to become uninhabitable? I certainly don’t think so.
- cletus 5y ago
  Again, to reiterate: I'm not denying human impact on climate change. Let's just get that out of the way. But your claim about rate of change, which is often repeated, is actually wrong [1]: > Unlike the relatively stable climate Earth has experienced over the last 10,000 years, Earth's climate system underwent a series of abrupt oscillations and reorganizations during the last ice age between 18,000 and 80,000 years ago ... There are twenty-five of these distinct warming-cooling oscillations (Dansgaard 1984) which are now commonly referred to as Dansgaard-Oeschger cycles, or D-O cycles. One of the most surprising findings was that the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C (Huber et al. 2006). Furthermore, the cooling occurred much more gradually, giving these events a saw-tooth shape in climate records from most of the Northern Hemisphere (Figure 1). [1]: https://www.nature.com/scitable/knowledge/library/abrupt-climate-change-during-the-last-ice-24288097/ https://www.nature.com/scitable/knowledge/library/abrupt-cli...
  - raffraffraff 5y ago
    Regardless of whether or not high rates of change happened in the past, they're not good for stability of life. That 10,000 years of stability was crucial to the evolution of our species and most food we eat (wheat being a huge example). So I don't think you can shrug it off and say "pah, this all happened before". So did WWII, and I wouldn't like to repeat it just because. We're looking at mass extinctions, loss of whole ecosystems, more wildfires, more storms. Not good things. Worse if you do it to yourself.
    - slavik81 5y ago
      We're looking at mass extinctions either way. The holocene extinction started before anthropogenic climate change began and will continue even after we restabilize the climate. There's a lot more we'll have to do if we want to protect our remaining wildlife.
    - cletus 5y ago
      > Regardless of whether or not high rates of change happened in the past, they're not good for stability of life. Let the moving goalposts begin. If the last 10,000 years of relative climate stability is unusual--and it seems to be at least within the context of the last 100,000 years--then how can you argue it's "bad for life"? This is the point of my comment: people have a warped view of "normal" as being the first thing they experience. For example: sea level changes in the last 20,000 years are massive [1]. Over that time the Sahara was a desert, became tropical and became a desert again (~6200 years ago) [2]. Climate change is viewed by many as a significant factor in the Bronze Age Collapse [3]. > So I don't think you can shrug it off and say "pah, this all happened before". So did WWII Seriously? [1]: https://judithcurry.com/2011/07/12/historic-variations-in-sea-levels-part-1-from-the-holocene-to-romans/ https://judithcurry.com/2011/07/12/historic-variations-in-se... [2]: https://en.wikipedia.org/wiki/Sahara#:~:text=By%20around%204200%20BCE%2C%20however,was%20about%2013%2C000%20years%20ago https://en.wikipedia.org/wiki/Sahara#:~:text=By%20around%204.... [3]: https://www.latimes.com/science/la-xpm-2013-aug-15-la-sci-sn-climate-change-late-bronze-age-civilization-collapse-20130814-story.html https://www.latimes.com/science/la-xpm-2013-aug-15-la-sci-sn...
sooheon 5y ago
> I'm skeptical about doom and gloom predictions of runaway climate change The doom and gloom isn't for the Earth on a planetary scale. It will be just fine as a celestial body, but the biofilm stuck to the surface may be significantly inconvenienced.
- mellavora 5y ago
  Naw, only the multi-celled organisms. Most of us will be just fine.
  - JohnWhigham 5y ago
    Why is this an acceptable sentiment to have? This defeatist "who cares, the planet will be fine!" stance? Who gives a shit if it's happened numerous times in the past? Do you just want to sit by idly and let things get worse in what time you have left on the planet?
    - marcosdumay 5y ago
      It started as an answer to the "restore nature, kill all humans" environmentalist ideologies that appeared at the 70's to 90's. It then became an attack at the "I don't care about Nature" anti-enviromentalism from the 80's to 00's. Nowadays I think this comment has no target, it's just repeated as a joke.
  - sooheon 5y ago
    Yeah, it's too bad multiple functioning neurons wired together seems to be a necessary condition for cognition.
deleted 5y ago
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raducu 5y ago
Earth will be completely unhospitable in the next billion years, at least for aerobic life. That I find fascinating! 200-500 million years after Earth formed, life was there. We witness it now and 1 billion years from now it will all be gone. A bit like "tears in rain", or more like "tears in vacuum/hard radiation".
- eloff 5y ago
  That depends on if we're still around or not by then. That's a long time, so I don't like our chances. But we could well engineer our way out of that predicament if technology and civilization keeps progressing.
thombat 5y ago
> My favourite example: for the first 60M years of trees existing, there were no organisms to digest the wood of dead trees. They just sat there or maybe burned. This is where 95% of the coal comes from. Intuitively that seems almost unbelievable, given how quickly microbes evolve to exploit potential food sources, including novel types of plastics. And Wikipedia says of it: "However, a 2016 study largely refuted this idea, finding extensive evidence of lignin degradation during the Carboniferous, and that shifts in lignin abundance had no impact on coal formation. They suggested that climatic and tectonic factors were a more plausible explanation." https://en.wikipedia.org/wiki/Coal#Formation https://en.wikipedia.org/wiki/Coal#Formation
- jacquesm 5y ago
  If you already have a large variety of microbes capable of digesting a lot of different stuff then that gives a good starting point. Back then that may not have been the case.
  - rlpb 5y ago
    Then publish a paper and cite it from the Wikipedia page? I find it astonishing that you seem to be arguing against the current body of documented research into the topic and without citation. Do you not think that the existing literature has already considered your revelation? What does the existing literature have to say about it? Edit: I mean, what I see here is: <parent> Here's the existing body of research on this topic. <jacquesm> I disagree. How does this add to the discussion?
    - jacquesm 5y ago
      I think you misread my comment.
    - Talanes 5y ago
      It's a single study, which is still only presented as a counterpoint to the "nothing could digest lignin yet" hypothesis in the Wikipedia article that the parent linked. That HARDLY counts as "the existing body of research on this topic." What are YOU adding to the conversation? At least the gp comment was engaging with the intuitive reasoning line of the topic, you're just aggressively nitpicking people over your own misreadings.
technothrasher 5y ago
> But the Earth will (ultimately) be fine. What does that even mean? The Earth will be what it is. There is no 'fine' or 'not fine'. "Save the planet" really means "keep the planet in a state that is good for us."
taneq 5y ago
I agree that life will be fine, I don't think the total-extinction-of-everything people are right. Earth will be fine. Some species will thrive, others will die out, generalists will do well at first and then as the environment re-stabilises they will speciate into specialists. I do think, however, that this process is subjectively not going to be very fun for the species involved, especially in the first 10-20%.

by cletus 5y ago

deleted 5y ago

[deleted]

ahevia 5y ago

While you correctly pointed out that human activity is contributing to climate change. You forgot to mention how unprecedented the rate at which the climate is changing. A process that normally takes tens of thousands of years is happening within a 3-4 human lifetimes. Far too quickly for organisms to adapt. “Doom & gloom” is a defined differently to many people. What exactly do you mean here? Are humans going extinct & Earth is going to become uninhabitable? I certainly don’t think so.

cletus 5y ago
Again, to reiterate: I'm not denying human impact on climate change. Let's just get that out of the way. But your claim about rate of change, which is often repeated, is actually wrong [1]: > Unlike the relatively stable climate Earth has experienced over the last 10,000 years, Earth's climate system underwent a series of abrupt oscillations and reorganizations during the last ice age between 18,000 and 80,000 years ago ... There are twenty-five of these distinct warming-cooling oscillations (Dansgaard 1984) which are now commonly referred to as Dansgaard-Oeschger cycles, or D-O cycles. One of the most surprising findings was that the shifts from cold stadials to the warm interstadial intervals occurred in a matter of decades, with air temperatures over Greenland rapidly warming 8 to 15°C (Huber et al. 2006). Furthermore, the cooling occurred much more gradually, giving these events a saw-tooth shape in climate records from most of the Northern Hemisphere (Figure 1). [1]: https://www.nature.com/scitable/knowledge/library/abrupt-climate-change-during-the-last-ice-24288097/ https://www.nature.com/scitable/knowledge/library/abrupt-cli...
- raffraffraff 5y ago
  Regardless of whether or not high rates of change happened in the past, they're not good for stability of life. That 10,000 years of stability was crucial to the evolution of our species and most food we eat (wheat being a huge example). So I don't think you can shrug it off and say "pah, this all happened before". So did WWII, and I wouldn't like to repeat it just because. We're looking at mass extinctions, loss of whole ecosystems, more wildfires, more storms. Not good things. Worse if you do it to yourself.
  - slavik81 5y ago
    We're looking at mass extinctions either way. The holocene extinction started before anthropogenic climate change began and will continue even after we restabilize the climate. There's a lot more we'll have to do if we want to protect our remaining wildlife.
  - cletus 5y ago
    > Regardless of whether or not high rates of change happened in the past, they're not good for stability of life. Let the moving goalposts begin. If the last 10,000 years of relative climate stability is unusual--and it seems to be at least within the context of the last 100,000 years--then how can you argue it's "bad for life"? This is the point of my comment: people have a warped view of "normal" as being the first thing they experience. For example: sea level changes in the last 20,000 years are massive [1]. Over that time the Sahara was a desert, became tropical and became a desert again (~6200 years ago) [2]. Climate change is viewed by many as a significant factor in the Bronze Age Collapse [3]. > So I don't think you can shrug it off and say "pah, this all happened before". So did WWII Seriously? [1]: https://judithcurry.com/2011/07/12/historic-variations-in-sea-levels-part-1-from-the-holocene-to-romans/ https://judithcurry.com/2011/07/12/historic-variations-in-se... [2]: https://en.wikipedia.org/wiki/Sahara#:~:text=By%20around%204200%20BCE%2C%20however,was%20about%2013%2C000%20years%20ago https://en.wikipedia.org/wiki/Sahara#:~:text=By%20around%204.... [3]: https://www.latimes.com/science/la-xpm-2013-aug-15-la-sci-sn-climate-change-late-bronze-age-civilization-collapse-20130814-story.html https://www.latimes.com/science/la-xpm-2013-aug-15-la-sci-sn...

sooheon 5y ago

> I'm skeptical about doom and gloom predictions of runaway climate change The doom and gloom isn't for the Earth on a planetary scale. It will be just fine as a celestial body, but the biofilm stuck to the surface may be significantly inconvenienced.

mellavora 5y ago
Naw, only the multi-celled organisms. Most of us will be just fine.
- JohnWhigham 5y ago
  Why is this an acceptable sentiment to have? This defeatist "who cares, the planet will be fine!" stance? Who gives a shit if it's happened numerous times in the past? Do you just want to sit by idly and let things get worse in what time you have left on the planet?
  - marcosdumay 5y ago
    It started as an answer to the "restore nature, kill all humans" environmentalist ideologies that appeared at the 70's to 90's. It then became an attack at the "I don't care about Nature" anti-enviromentalism from the 80's to 00's. Nowadays I think this comment has no target, it's just repeated as a joke.
- sooheon 5y ago
  Yeah, it's too bad multiple functioning neurons wired together seems to be a necessary condition for cognition.

deleted 5y ago

[deleted]

raducu 5y ago

Earth will be completely unhospitable in the next billion years, at least for aerobic life. That I find fascinating! 200-500 million years after Earth formed, life was there. We witness it now and 1 billion years from now it will all be gone. A bit like "tears in rain", or more like "tears in vacuum/hard radiation".

eloff 5y ago
That depends on if we're still around or not by then. That's a long time, so I don't like our chances. But we could well engineer our way out of that predicament if technology and civilization keeps progressing.

thombat 5y ago

> My favourite example: for the first 60M years of trees existing, there were no organisms to digest the wood of dead trees. They just sat there or maybe burned. This is where 95% of the coal comes from. Intuitively that seems almost unbelievable, given how quickly microbes evolve to exploit potential food sources, including novel types of plastics. And Wikipedia says of it: "However, a 2016 study largely refuted this idea, finding extensive evidence of lignin degradation during the Carboniferous, and that shifts in lignin abundance had no impact on coal formation. They suggested that climatic and tectonic factors were a more plausible explanation." https://en.wikipedia.org/wiki/Coal#Formation https://en.wikipedia.org/wiki/Coal#Formation

jacquesm 5y ago
If you already have a large variety of microbes capable of digesting a lot of different stuff then that gives a good starting point. Back then that may not have been the case.
- rlpb 5y ago
  Then publish a paper and cite it from the Wikipedia page? I find it astonishing that you seem to be arguing against the current body of documented research into the topic and without citation. Do you not think that the existing literature has already considered your revelation? What does the existing literature have to say about it? Edit: I mean, what I see here is: <parent> Here's the existing body of research on this topic. <jacquesm> I disagree. How does this add to the discussion?
  - jacquesm 5y ago
    I think you misread my comment.
  - Talanes 5y ago
    It's a single study, which is still only presented as a counterpoint to the "nothing could digest lignin yet" hypothesis in the Wikipedia article that the parent linked. That HARDLY counts as "the existing body of research on this topic." What are YOU adding to the conversation? At least the gp comment was engaging with the intuitive reasoning line of the topic, you're just aggressively nitpicking people over your own misreadings.

technothrasher 5y ago

> But the Earth will (ultimately) be fine. What does that even mean? The Earth will be what it is. There is no 'fine' or 'not fine'. "Save the planet" really means "keep the planet in a state that is good for us."

taneq 5y ago

I agree that life will be fine, I don't think the total-extinction-of-everything people are right. Earth will be fine. Some species will thrive, others will die out, generalists will do well at first and then as the environment re-stabilises they will speciate into specialists. I do think, however, that this process is subjectively not going to be very fun for the species involved, especially in the first 10-20%.