Under a Green Sky
More than 200 million years ago, a cataclysmic event known as the Permian extinction destroyed more than 90% of all species and nearly 97% of all living things. Its origins have long been a puzzle for paleontologists, and during the 1990s and the early part of this century a great battle was fought between those who thought that death had come from above and those who thought something more complicated was at work.Paleontologist Peter D. Ward, fresh from helping prove that an asteroid had killed the dinosaurs, turned to the Permian problem, and he has come to a stunning conclusion. In his investigations of the fates of several groups of mollusks during those extinctions and others, he discovered that the near-total devastation at the end of the Permian was caused by rising levels of carbon dioxide leading to climate change. But it's not the heat (nor the humidity) that's directly responsible for the extinctions, and the story of the discovery of what is responsible makes for an fascinating, globe-spanning adventure.
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7recommend
14mentions
9people
2021–2025years
79% recommend14% neutral7% critical
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What Hacker News says
- The AMOC collapsing (I have no idea why the title says 'Gulf Stream' as that is different and not mentioned in the post), has far more disastrous implications than destroying the climate of Europe.
It's the beginning of the process of ocean de-oxygenation, ultimately creating a lifeless ocean that emits hydrogen sulfide instead of oxygen. It would completely disrupt the planetary food change, make the ocean poisonous, and fundamentally alter life on this planet in unimaginable ways.
For a more detailed look at the issue I highly recommend Peter Ward's "Under a Green Sky".
- The paleontologist Peter Ward has made a fairly compelling argument (in both academic research and the popular science book Under a Green Sky), that virtually all major extinction events are related to sudden rises in atmospheric CO2. A lot more happens when CO2 rises quickly other than it getting warmer. A major issue is it's impact on the oceans, which can become anoxic [0], causing them to emit hydrogen sulfide instead of oxygen. Such an event would be devastating to our current ecosystem.
> There won't be an extinction event.
This also ignores the fact that we are currently in the 6th largest extinction event in the history of life on this planet [1]. Elizabeth Kolbert's The Sixth Extinction is a great book on this (and the history of our understanding of species extinction as well).
So aside for being naive about the science, your comment reads a bit like claiming you don't think it will rain today while in the midst of being soaked in a massive rain storm.
- For slowing currents, at least in the long run, there's reasonable evidence that, in the extreme, the ocean becomes anoxic[0], stops producing oxygen and starts releasing hydrogen sulfide instead. It's happened a few times in Earth's history [0] suspected to usually be caused climate change impacting ocean circulation.
Peter Ward's Under a Green Sky does a fantastic overview of this subject, and outlines how most mass extinction events have likely been triggered by sudden changes in atmospheric CO2 through various mechanism.
- > I'm curious how you think that the damage of climate change can be worse than this.
Oh, much worse.
First off we, fertilizer or no, we're already facing crop failures in the US [0] and will continue to face even more extreme crop failures [1]. Even if we had unlimited fertilizer we've already signed up for massive famine.
But if you really want to talk about the unmitigated climate change path, which is what happens if we choose not to keep hydrocarbons in the ground, I really recommend reading Peter Ward's Under a Green Sky [2].
He's a respected geologist that makes a compelling case that the vast majority of mass extinction events were caused by rapid rises in CO2.
One of the realistic scenarios we're facing, he argues, is the break down of the AMOC ultimately leading to the oceans becoming anoxic and releasing hydrogen sulfide rather than oxygen. The entire marine ecosystem is essentially wiped out except for some cyanobacteria. The oceans are the foundation of all of our food systems. It would make the planet uninhabitable my most complex life of today. This has happened before in Earth's climate history.
All of the "bad-awful" but not-extinction event scenarios assume that we do not burn all of the fossil fuel reserves currently leased. We are already looking at a grim future, but given that we're rapidly pumping millions of years of stored CO2 into the atmosphere, upper bounds for the damage we can do are tremendous.
0. https://www.nytimes.com/2023/08/09/us/kansas-wheat-harvest-d... 1. https://www.aljazeera.com/news/2023/7/4/scientists-warn-of-c... 2. https://www.amazon.com/Under-Green-Sky-Warming-Extinctions/d...
- Recent research argued that the loss of the Greenland ice sheet is now inevitable: https://www.theguardian.com/environment/2022/aug/29/major-se...
Given the lag in the climate, isn’t 1.5C warming more or less unavoidable now? We would need extremely steep emissions reductions that aren’t happening.
I enjoyed ‘Under a Green Sky’, which combines a brief history of palaeontology (and amusing academic point settling) with the prediction that warming will eventually cause huge releases of hydrogen sulphide.
We are perhaps entering a negative feedback loop where disruption makes countries less keen to work together on emissions reductions as metaphorical bridges get pulled up (is Russia going to bother even pretending to care any more?).
- Maybe we because we can observe these disasters happening in real time?
I find it absolutely wild that you can claim not to see climate disasters that are actively unfolding around us.
The first thing that really woke me up was the sudden loss of global sea ice in 2016. Take a look at the arctic death spiral if you aren't familiar already [0]. In 2012 if you mentioned that the response was "well yea but the antarctic is growing!!". There were good explanations for why that what happening during global warming, but that's no longer necessary since the antarctic is also declining rapidly [1].
Then there's lake Mead. I can't imagine you haven't been paying attention to what's happening there but we're on the path to reaching dead pool in a few years [2]. And yes, this is also due to poor resource management, but it is exacerbated by climate change and desertification of the region.
Then there's the amazon rain forest, which was once a carbon sink, becoming a net carbon emitter [3]
But the most important part of all of this, is that these events (which represent just a few examples of the impacts of climate changes) are not the new normal. Because the rate co2[4] and ch4[5] are being emitted is accelerating we're no where near a new stability point. All of the things we see now are just the beginning of a process that will only continue to accelerate each year for the rest of your life.
And that's just what we can observe and predict. Thwaites glacier, for example, will very likely collapse at some point in the next 100 years. We have no idea when, but when it does it will cause massive and near instant sea level rise. Far more concerning is that this tons of geological evidence that there are feed back triggers that cause rapid rise in GHGs and temperature and we don't know exactly when we might cross these. The book Under a Green Sky, by paleontologist Peter Ward lays out rather convincing evidence that the majority of extinction events have been caused by rapid climate change triggered by changes in CO2.
I'm not sure why you don't give these things more credibility.
0. https://www.arcticdeathspiral.org/
1. https://twitter.com/ZLabe/status/1540742236807213058/photo/1
2. https://mead.uslakes.info/level.asp
3. https://www.theguardian.com/environment/2021/jul/14/amazon-r...
