Sixth Extinction - Ch. I: The Sixth Extinction

[Chris OConnor]

Sixth Extinction - Ch. I: The Sixth Extinction

Please use this thread to discuss the above-referenced chapter of The Sixth Extinction: An Unnatural History by Elizabeth Kolbert. You're also welcome to create your own threads if what you'd like to say doesn't necessarily pertain to a particular chapter.

[LevV]

In this first chapter of "The Sixth Extinction," Elizabeth Kolbert dives into the idea that our planet has gone through five major extinction events in its history. Now, she suggests, we're in the middle of a sixth one, and this time, it's mostly because of us humans.

Kolbert starts by talking about the Panamanian golden frog, a cute little amphibian almost wiped out by a fungus spread by human activity. This example sets the stage for the bigger picture: humans are changing the planet in ways that are causing many species to disappear.
This chapter really makes you think about how our actions impact the natural world. It raises some big questions about our responsibility to protect other species and what we can do to help stop this extinction crisis.

[Taylor]

It’s been a while since I read the Sixth Extinction and I am somewhat disappointed that I also gave the book away. Like many books of this sort, Kolbert is a documentarian, a historian. I recall having little doubt as to her assertion of the decline of species.
The extinction of flora and fauna is being observed and documented by professionals and laypeople enough to convince me that this is a fact and a problem.
The butterfly effect in essence teaches us that like dominoes the loss of a species invariably leads to the loss of another… so on and so forth.
Once a habitat has failed there is invariably regional collapse.
Certainly new species strive but the natural/historical foundation is forever gone.
We are witnessing a homogeneous evolution, via extinction.
Speciality is becoming increasingly rare while at the same time being over crowded.
Regardless of a personal opinion about SARS cov 2, it did demonstrate how quickly a virus can spread. The same types of events are happening at unrecorded levels and are even downplayed by denialism. Particularly when it comes to nebulous events like species collapse or extinction.
It seems to me that a mere ten years ago we were educated about how serious this phenomenon was and could be, ten years later and it is harder than ever to do anything about it. The cynicism and pessimism is to me, too strong today for much action to be taken.

[Robert Tulip]

I also read this a few years ago, and thought it was brilliant. However, Kolbert's other book, Under a White Sky, spread needless alarm about solar geoengineering, which is likely to be the main thing that can prevent mass extinction. Here is a review I wrote this year of a related book, Under a Green Sky, by Peter Ward.

Under a Green Sky by Peter Ward

Peter Ward, Professor of Palaeontology at University of Washington, is a leading scholar on the causes of mass extinction. Under A Green Sky, published in 2007, explains the risk that the stopping of the Atlantic Meridional Overturning Circulation could cause mass extinction, as the same thing has happened numerous times in Earth's geological history. This explanation is important to understand why the sequencing of climate policy has to reverse to make higher albedo the top priority while work on carbon proceeds more gradually.

Extinction has become a major field of scientific research. Under A Green Sky provides an excellent history of the major paradigm shifts that have occurred in extinction studies. Until the 1980 Alvarez article detailing the asteroid theory for the end of the dinosaur age, Ward says most science assumed that all extinctions were caused by terrestrial processes. Even after abundant geological evidence of the asteroid many scientists refused to believe it. Even after the Chicxulub Crater was confirmed as the cause in 1991, it took until 2010 (after the publication of this book) for the official scientific consensus to change. But the asteroid led to a sort of asteroid craze in the media, with some scientists even publishing papers wrongly attributing other extinctions to asteroids.

The Permian Extinction about 252 million years ago, known as the Great Dying, is the biggest ever, killing off more than half of all species, with estimates up to 96% of marine species going extinct at that time. Ward explains that it was caused by a series of giant belches of hydrogen sulphide, a deadly gas caused when ocean currents stop. The line of causation, as Ward explains in this interview with Wired, is that vast fields of lava opened up, known as the Siberian Traps. This in turn caused CO2 level to rise, warming the planet and stopping ocean currents. When oceans stop overturning with oxygen-rich water from the surface descending to the deep, life in the deep dies. This is known as Euxinia, named after the stratified waters of the Black Sea where there is no oxygen below the surface layer. When the whole world ocean became euxinic, the rotting of the anoxic deep made so much hydrogen sulphide that it ended the Permian Era. Under a Green Sky is named for this event, which Ward says could have also happened in a dozen other mass extinctions.

This is exactly what is likely to happen to our planet in coming centuries if we do not embrace solar geoengineering now as the primary climate security agenda. While obviously the carbon problem has to be fixed, it is nowhere near as urgent or amenable to solution as albedo. The inertia and momentum of the fossil fuel economy are so vast that there is no prospect, without higher albedo, that the world could avoid the high risk of a Permian-type catastrophe. Ward observes that all the mass extinction events except the singular K-T asteroid event appear to have been caused by hydrogen sulphide from high levels of CO2. That shows the immensely dangerous precedents for the current unprecedented speed of CO2 increase. But it does not mean that directly addressing the CO2 problem must be the best solution, as generally assumed. Rebrightening the planet is needed to buy time to develop workable carbon strategies.

I first encountered Peter Ward when I read his brilliant co-authored book Rare Earth, which explains why the high complexity of life on Earth is likely to be extremely rare in the universe. The numerous factors that have combined to enable our four billion years of evolution reveal that life is inherently far more fragile and sensitive to shock than is generally assumed.

Peter Ward continues to campaign for better understanding of the geological context of climate change, including in an excellent recent discussion with Nate Hagens and a TED talk in 2013. Although I have not found any comment from him on geoengineering, he does say in the Wired interview that we have to save the ice caps, because if the ice caps go, the hydrogen sulfide scenario is the inevitable next step. Despite the heavy seriousness of extinction, he writes with a friendly anecdotal personal style, with numerous great stories of his geological adventures around the world, making his work accessible to a broader audience. With a recent study suggesting the AMOC could suddenly shut down any time from 2025, appreciating this geological risk of hydrogen sulphide poisoning is helpful to understand the security context of drastic changes to ocean currents and their potential to cause mass extinction.

[Taylor]

https://youtube.com/shorts/d2_ZJnSuq_Y? ... VVPuflVXlE

Species loss and habitat destruction are synonymous.

[Taylor]

https://acp.copernicus.org/articles/24/7253/2024/

A study of albedo effects using aerosol (water) to form clouds over the northern pacific ocean. This wasn’t a large scale event, but sufficient enough to verify modeling standards. Often studies have to be developed and experimented on just to verify if the experts are using accurate methods, and too develop better models for those studies.
I agree with Robert that Co2 reduction isn’t the only way to combat global warming and the effects of it on habitat loss and species survival. Larger scale implementation of albedo experiments and action should be given equal attention as reduction.
It seems that there’s only a narrow focus on reducing emissions and less on definitive environmental measures such as direct intervention.
Energy demand is increasing globally, cheap fuel (fossil) is the immediate source, climate engineering is a passenger science that should instead be pursued at large scale. Nuclear energy is a viable clean source but is carrying a stigma that I believe is to the detriment of that energy demand.
Permitting seems to be strident and is likely holding upscale businesses from implementing alternative solutions.

[Taylor]

https://en.wikipedia.org/wiki/2022_Hung ... nd_tsunami

Interesting how this eruption event actually helped increase global warming, by the sheer volume of water forced into the upper atmosphere it held more radiative heat than is typical.
That extra moisture is estimated to remain for several or more years. It has been described as being a saturated sponge and is a likely cause for the record heatwaves of 2022 and possibly up to the present.
The aerosol affects from sulfur dioxide was nullified by that moisture, the subsequent cooling failed to happen.

[LanDroid]

Drat I just realized I have a "young readers' adaptation" of this book. Will have to get an adult copy from the library...