Mass extinction pulses driven by major marine carbon cycle perturbations (2020) | Hacker News Reader

Mass extinction pulses driven by major marine carbon cycle perturbations (2020)

nature.com

28 pointsmontalbano11 comments

Help. Could someone summarize in layperson's terms? It's bad news, isn't it?

Someone correct me if I’m wrong, but sounds like bad gas released from the ground caused the oceans to acidify, destroying most species, this in turn caused land animals to follow suit.

earth is fubar, pay $59 for more details.

This paper presents new evidence that in the past, rapid increases in atmospheric CO2 concentrations resulted in ocean acidification, which resulted in large numbers of marine species going extinct, which resulted in large numbers of land species going extinct. This shouldn't really come as a surprise to anyone. The only question is at what level of CO2 this happened in the past, and how this compares to the present day. That information, unfortunately, is not in the abstract, and I don't have access to the full article.

Can someone explain how ocean animals going extinct killed land animals? Not that many land species depend on ocean life for food, do they? So what's the cause-and-effect mechanism?

I think ecosystems are more interlinked than we realise, and perhaps conditions became more hostile to animal life on land too over time.

Marine ecosystems got wiped out quicker than land ones, perhaps because there is a tipping point in oceans beyond a certain level of acidification, temperature increase and oxygen depletion - after which marine life dies relatively fast, faster than it can evolve

The mention of oxygen depletion reminds me of an interesting development I recently learned of with Bryde’s whales off the coast of Thailand, although it seems more to do with direct pollution. Apparently, there’s been so much pollution from the rivers that the water is hypoxic and fish need to swim closer to the surface of water. So these whales have adapted to that adaptation by treading water and just leaving their mouths open.

It’s just one of many visual signs that things are changing, seemingly at rapid pace, in the oceans. It’s a wonderful thing to see the whales finding such a technique and teaching it to others, but it’s scary at its core.

https://www.scientificamerican.com/podcast/episode/polluted-...

https://youtu.be/-mVG6MtH-Kc

"Scientists estimate that 50-80% of the oxygen production on Earth comes from the ocean"

https://oceanservice.noaa.gov/facts/ocean-oxygen.html

Good question. This (PhD from Smithsonian interview) might be part of the answer (details specific to PT extinction). To quote just a bit:

"[90% of ocean species dying] basically hit a reset button on ecosystems in the ocean ... These animals were living in coastal environments, eating seafood that washed up on the beach, and over time became more and more dedicated to living in the ocean."

[https://www.splendidtable.org/story/2015/04/10/how-land-anim...]

Here is a popular article about the study https://scitechdaily.com/driver-identified-of-the-largest-ma...

Bad news in the sense that last time the atmosphere and oceans absorbed a lot of extra carbon (and too many nutrients from acid rain erosion running to rivers and oceans, causing lack of oxygen for marine life) most marine and land animals on Earth got wiped out over time, and it took millions of years for animal life to re-establish. It seems to have been caused by volcanic activity in Siberia and not dissolution of methane hydrates.

Well this is terrifying.

Venus was meant to be a cautionary tale, not an example to emulate.

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