I should know better by now than to promise a blog post before it’s done. My brain has always taken that sort of thing as a challenge to its ability to be useless. Today was unexpectedly difficult, so the more in-depth post will have to wait. I don’t know why my brain will cooperate on one project and not another, but I’ve yet to figure out a reliable way to deal with that problem. Shouldn’t be long now, I’ve only been trying for two or three decades. Unfortunately, my alternative offering isn’t likely to taste much better than a piece about treatment of refugees. The biggest downside of running a climate-focused blog in this era is that the news is mostly bad.
Global heating is causing such a drastic change to the world’s oceans that it risks a mass extinction event of marine species that rivals anything that’s happened in the Earth’s history over tens of millions of years, new research has warned.
Accelerating climate change is causing a “profound” impact upon ocean ecosystems that is “driving extinction risk higher and marine biological richness lower than has been seen in Earth’s history for the past tens of millions of years”, according to the study.
The world’s seawater is steadily climbing in temperature due to the extra heat produced from the burning of fossil fuels, while oxygen levels in the ocean are plunging and the water is acidifying from the soaking up of carbon dioxide from the atmosphere.
This means the oceans are overheated, increasingly gasping for breath – the volume of ocean waters completely depleted of oxygen has quadrupled since the 1960s – and becoming more hostile to life. Aquatic creatures such as clams, mussels and shrimp are unable to properly form shells due to the acidification of seawater.
I’m sorry, what was that? Did you say oceanic oxygen levels are plunging? Who’d have thought? It should still be a long time before the drop in oxygen translates to major hydrogen sulfide buildup, but given that seafood makes up a good chunk of humanity’s protein intake, maybe this is something to which we should be responding? Maybe we should be taking action now for the protein shortage that we know is coming.
Just a thought.
Another thought, if you’ll indulge me: It seems like a bad thing when something called The Great Dying becomes relevant to current events:
All of this means the planet could slip into a “mass extinction rivaling those in Earth’s past”, states the new research, published in Science. The pressures of rising heat and loss of oxygen are, researchers said, uncomfortably reminiscent of the mass extinction event that occurred at the end of the Permian period about 250m years ago. This cataclysm, known as the “great dying”, led to the demise of up to 96% of the planet’s marine animals.
I think it’s worth noting here that this extinction event was not limited to the ocean. The ocean seems to have been first, but by the end of it, 70% of land-based vertebrates were also dead. That’s not because all those animals got their food from the ocean, but rather because of the ecological effects of both the same conditions that killed the oceans, and the fallout from that death.
We are quite literally terraforming our planet, in a way that will make more and more of it hostile to humanity and the species on which we depend. Our only hope is to try to take control of a train that was beginning to get out of control even as we learned how to build actual trains.
“Even if the magnitude of species loss is not the same level as this, the mechanism of the species loss would be the same,” said Justin Penn, a climate scientist at Princeton University who co-authored the new research.
“The future of life in the oceans rests strongly on what we decide to do with greenhouse gases today. There are two vastly different oceans we could be seeing, one devoid of a lot of life we see today, depending on what we see with CO2 emissions moving forward.”
Truly catastrophic extinction levels may be reached should the world emit planet-heating gases in an unrestrained way, leading to more than 4C of average warming above pre-industrial times by the end of this century, the research found. This would trigger extinctions that would reshape ocean life for several more centuries as temperatures continue to climb.
But even in the better case scenarios, the world is still set to lose a significant chunk of its marine life. At 2C of heating above the pre-industrial norm, which is forecast as likely even under current climate pledges by the world’s governments, around 4% of the roughly two million species in the oceans will be wiped out.
Fish and marine mammals that live in polar regions are most vulnerable, according to the study, as they will be unable to migrate to suitably cooler climes, unlike tropical species. “They will just have nowhere to go,” said Penn.
The threat of climate change is amplifying the other major dangers faced by aquatic life, such as over-fishing and pollution. Between 10% and 15% of marine species are already at risk of extinction because of these various threats, the study found, drawing upon International Union for Conservation of Nature data.
John Bruno, a marine ecologist at the University of North Carolina who was not involved in the study, said the new research appeared “sound” but it differed from previous studies on the topic that suggest species will mainly disperse to new areas rather than be completely snuffed out.
“It’s very different from what most prior work has developed. But that doesn’t mean they are wrong,” Bruno said. “I think this new work is challenging some of our current assumptions about the geographic patterns of looming extinction in the ocean.”
Bruno said that while mass extinctions are likely from extreme heating in the future, the current impacts from climate change and other threats should be concerning enough for policymakers and the public.
“Personally, I’m a lot more worried about the ecosystem degradation we’re already seeing after less than 1C of warming,” he said.
“We don’t need to look to a world so warmed over humanity has been wiped out – we’re already losing untold biodiversity and ecosystem functioning with even the relatively modest warming of the last 50 years.”
I think it’s worth remembering that when it comes to climate change, “truly catastrophic” means “all humans will probably die”, which comes some time after “so many people will die that the 20th century looks pleasantly peaceful by comparison”.
Despite the fact that a number of feedback loops are almost certainly adding to the momentum of this climate shift, this is not an on/off situation. We can do things to take away from that momentum, and to get people – and possibly even some ecosystems – out of the tracks of this metaphorical train. The longer we delay, the fewer options we have, but we’re by no means out of options, and anyone who says otherwise is supporting the agenda of the worst people in the world, whether they mean to or not. With everything going on, it’s not at all surprising that people turn to despair and doomsaying. The conclusions given to us by misery and pessimism always seem inescapable when we come to them. In the grips of a depressive episode, it feels certain that life will never get better. In the heart-pounding fear of a panic attack, it seems certain that our bodies will inevitably give out. In a world where despair benefits the rich and powerful, hope is both a necessary, and a revolutionary act.
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