Sixth extinction? (Introduction)
by David Turell 
, Saturday, June 20, 2015, 15:03 (3232 days ago)
Paul Ehrlich, purveyor of gloom and doom is back:-http://www.sciencedaily.com/releases/2015/06/150619152142.htm-"There is no longer any doubt: We are entering a mass extinction that threatens humanity's existence.- "That is the bad news at the center of a new study by a group of scientists including Paul Ehrlich, the Bing Professor of Population Studies in biology and a senior fellow at the Stanford Woods Institute for the Environment. Ehrlich and his co-authors call for fast action to conserve threatened species, populations and habitat, but warn that the window of opportunity is rapidly closing.-"'[The study] shows without any significant doubt that we are now entering the sixth great mass extinction event," Ehrlich said.-"Although most well known for his positions on human population, Ehrlich has done extensive work on extinctions going back to his 1981 book, Extinction: The Causes and Consequences of the Disappearance of Species. He has long tied his work on coevolution, on racial, gender and economic justice, and on nuclear winter with the issue of wildlife populations and species loss.-"There is general agreement among scientists that extinction rates have reached levels unparalleled since the dinosaurs died out 66 million years ago. However, some have challenged the theory, believing earlier estimates rested on assumptions that overestimated the crisis."-One must read Julian Simon to get a balanced view:-http://archive.wired.com/wired/archive/5.02/ffsimon_pr.html-"This is the litany : Our resources are running out. The air is bad, the water worse. The planet's species are dying off - more exactly, we're killing them -at the staggering rate of 100,000 per year, a figure that works out to almost 2,000 species per week, 300 per day, 10 per hour, another dead species every six minutes. We're trashing the planet, washing away the topsoil, paving over our farmlands, systematically deforesting our wildernesses, decimating the biota, and ultimately killing ourselves. - "Simon paints a somewhat different picture of the human condition circa 1997. -"'Our species is better off in just about every measurable material way," he says. "Just about every important long-run measure of human material welfare shows improvement over the decades and centuries, in the United States and the rest of the world. Raw materials - all of them - have become less scarce rather than more. The air in the US and in other rich countries is irrefutably safer to breathe. Water cleanliness has improved. The environment is increasingly healthy, with every prospect that this trend will continue.-"'Fear is rampant about rapid rates of species extinction," he continues, "but the fear has little or no basis. The highest rate of observed extinction, though certainly more have gone extinct unobserved, is one species per year ...'" -Simon won a famous economics bet with Ehrlich in 1980:-https://en.wikipedia.org/wiki/Simon%E2%80%93Ehrlich_wager
Sixth extinction? Why not?
by David Turell , Sunday, November 26, 2017, 15:16 (2342 days ago) @ David Turell
Extinction is part of evolution. Loss of a species is not wrong or a disaster:
https://www.washingtonpost.com/outlook/we-dont-need-to-save-endangered-species-extincti...
"Extinction is the engine of evolution, the mechanism by which natural selection prunes the poorly adapted and allows the hardiest to flourish. Species constantly go extinct, and every species that is alive today will one day follow suit. There is no such thing as an “endangered species,” except for all species. The only reason we should conserve biodiversity is for ourselves, to create a stable future for human beings. Yes, we have altered the environment and, in doing so, hurt other species. This seems artificial because we, unlike other life forms, use sentience and agriculture and industry. But we are a part of the biosphere just like every other creature, and our actions are just as volitional, their consequences just as natural. Conserving a species we have helped to kill off, but on which we are not directly dependent, serves to discharge our own guilt, but little else.
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"This is how evolution proceeds: through extinction. The inevitability of death is the only constant in life, and 99.9 percent of all species that have ever lived, as many as 50 billion, have already gone extinct. In 50 million years, Europe will collide with Africa and form a new supercontinent, destroying species (think of birds, fish and anything vulnerable to invasive life forms from another landmass) by irrevocably altering their habitats. Extinctions of individual species, entire lineages and even complete ecosystems are common occurrences in the history of life. The world is no better or worse for the absence of saber-toothed tigers and dodo birds and our Neanderthal cousins, who died off as Homo sapiens evolved. (According to some studies, it’s not even clear that biodiversity is suffering. The authors of another recent National Academy of Sciences paper point out that species richness has shown no net decline among plants over 100 years across 16,000 sites examined around the world.)
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"Humans should feel less shame about molding their environment to suit their survival needs. When beavers make a dam, they cause the local extinction of numerous riverine species that cannot survive in the new lake. But that new lake supports a set of species that is just as diverse. Studies have shown that when humans introduce invasive plant species, native diversity sometimes suffers, but productivity — the cycling of nutrients through the ecosystem — frequently increases. Invasives can bring other benefits, too: Plants such as the Phragmites reed have been shown to perform better at reducing coastal erosion and storing carbon than native vegetation in some areas, like the Chesapeake.
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"We should save whatever species and habitats can be easily rescued (once-endangered creatures such as bald eagles and peregrine falcons now flourish), refrain from polluting waterways, limit consumption of fossil fuels and rely more on low-impact renewable-energy sources.
"We should do this to create a stable, equitable future for the coming billions of people, not for the vanishing northern river shark. Conservation is needed for ourselves and only ourselves. All those future people deserve a happy, safe life on an ecologically robust planet, regardless of the state of the natural world compared with its pre-human condition. We cannot thrive without crops or pollinators, or along coastlines as sea levels rise and as storms and flooding intensify.
"Yet that robust planet will still erase huge swaths of animal and plant life. Even if we live as sustainably as we can, many creatures will die off, and alien species will disrupt formerly “pristine” native ecosystems. The sixth extinction is ongoing and inevitable — and Earth’s long-term recovery is guaranteed by history (though the process will be slow). Invasion and extinction are the regenerative and rejuvenating mechanisms of evolution, the engines of biodiversity.
"If this means fewer dazzling species, fewer unspoiled forests, less untamed wilderness, so be it. They will return in time. The Tree of Life will continue branching, even if we prune it back. The question is: How will we live in the meantime?"
Comment: A very wise essay. The bush of life with all its strange extremophiles tells us extinction never stops a diverse group of living organisms.
Sixth extinction? How do we know?:
by David Turell , Friday, May 10, 2019, 22:21 (1811 days ago) @ David Turell
This article questions predictions about species loss:
https://www.mercatornet.com/features/view/un-trumpets-an-extinction-crisis/22447
"This week the UN's Intergovernmental Science-Policy Platform for Biodiversity and Ecosystem Services (IPBES) released a summary of a terrifying 1500-page forecast of humanity's relationship with Mother Nature (yes, “Mother Nature” is back in vogue).
“'Around 1 million animal and plant species are now threatened with extinction, many within decades, more than ever before in human history,” says the IPBES, “and the rate of species extinctions is accelerating.”
"Grim, unparalleled, catastrophic, shocking, terrifying were just some of the adjectives decorating the world’s headlines. One summed up the media consensus: “UN: Life on Earth is nearing a state of collapse”.
***
"Many of the IPBES’s dire predictions may be true and should be heeded. It's impossible for a 1500-page report with 15,000 references written by 150 experts to get everything wrong. The extinction of a species, especially a cuddly vertebrate, is regrettable. Who would not like to see live dodos, or passenger pigeons, or Tasmanian tigers? But can we risk implementing radical “transformative change” to save the Seychelles earwig or the pygmy hog-sucking louse?
"The media swallowed this turgid report whole without cutting it, chewing it or digesting it. It is an abdication of journalistic objectivity, scepticism and common sense.
***
"Are one million plant and animal species really in danger of extinction? That’s the marquee question which journalists should have tackled.
"For starters, how many species are there? This is a fundamental question, but, surprisingly, all scientists can do is guesstimate. An influential 2011 paper in PLOS Biology estimated that there are 8.7 million species in the world, plus or minus 1.3 million. The IPBES seems to have adopted this figure. (There are no footnotes in its summary, making it difficult to check its claims, and the full report will be released later this year.) Previous estimates of the number of species ranged between 3 and 100 million. But of these 8.7 million, only about 1.3 million have been named and catalogued.
"So the claim that a million species are at risk of being wiped out means that species are disappearing before we even know that they existed. This may be true, but it illustrates how mind-bending the extinction claim is.
***
“'Every day, up to 150 species are lost. Every year, between 18,000 and 55,000 species become extinct,” said Ahmed Djoghlaf, head of the UN Convention on Biological Diversity in 2007. This is the kind of wild biodiversity rhetoric which coloured this week’s reporting.
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"The Red List of the International Union for Conservation of Nature is regarded as “the world's most comprehensive inventory of the global conservation status of plant and animal species.” According to the IUCN, “In the last 500 years, human activity is known to have forced 869 species to extinction”.
"Isn’t there a disconnect here? Using Mr Djoghlaf’s figures, 20,000 extinctions a year for 500 years implies that 10 million species have become extinct. Yet we can only name 869 of them. How can we prove that the other 9,999,131 species are extinct -- or even existed?
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"But over-egging the case for reform with horror stories makes it politically impossible to sell. Reforms, however worthy, are destined to fade from the front page into obscurity unless the IPBES respects human dignity, national interests and the political process. Sir Robert Watson says that "by its very nature, transformative change can expect opposition from those with interests vested in the status quo, but also that such opposition can be overcome for the broader public good”. The threats swaddled in this globalist gibberish will be spurned in Washington and Beijing, as well as Brazilia and Antananarivo. Elected politicians understand, even if the UN doesn't, that the survival, welfare and freedom of human beings is far more important than the fate of critically endangered salamanders."
Comment: Just like the alarm over global warming. If we only recognize one in eight million estimated species, how can we possibly know one million are trying to disappear?
Sixth extinction? How do we know?:
QUOTE: “Elected politicians understand, even if the UN doesn't, that the survival, welfare and freedom of human beings is far more important than the fate of critically endangered salamanders."
DAVID: Just like the alarm over global warming. If we only recognize one in eight million estimated species, how can we possibly know one million are trying to disappear?
It’s the usual scenario in which parties on both sides present extreme views and therefore undermine their own case. Articles like this can easily distract attention from the very real dangers of the current situation. The quote about “elected politicians” ignores the delicate balance which is necessary for ecosystems to survive or, at the very least, to work efficiently. You, David, have constantly emphasized this, and we as top predators rely on the chain beneath us for our survival. The survival, welfare and freedom of human beings depends on the fate, not of individual species but of the whole environment in which we live. The subject requires a broad view, and it encompasses all the factors that threaten us. Many of these are man-made, and although they may not lead to the extinction of the human race, they most certainly cause immense suffering to man and beast. Air and water pollution, pesticides, deforestation, fossil fuels etc. all contribute even now to the suffering and premature deaths of huge numbers of humans, and to my mind it is totally irresponsible for any politician to pretend that we do not already have a crisis on our hands because of human interference with nature. I have been greatly encouraged, however, by the efforts of the younger generation to make the environment a priority concern for all governments.
Sixth extinction? How do we know?:
by David Turell , Saturday, May 11, 2019, 17:34 (1811 days ago) @ dhw
QUOTE: “Elected politicians understand, even if the UN doesn't, that the survival, welfare and freedom of human beings is far more important than the fate of critically endangered salamanders."
DAVID: Just like the alarm over global warming. If we only recognize one in eight million estimated species, how can we possibly know one million are trying to disappear?
dhw: It’s the usual scenario in which parties on both sides present extreme views and therefore undermine their own case. Articles like this can easily distract attention from the very real dangers of the current situation. The quote about “elected politicians” ignores the delicate balance which is necessary for ecosystems to survive or, at the very least, to work efficiently. You, David, have constantly emphasized this, and we as top predators rely on the chain beneath us for our survival. The survival, welfare and freedom of human beings depends on the fate, not of individual species but of the whole environment in which we live. The subject requires a broad view, and it encompasses all the factors that threaten us. Many of these are man-made, and although they may not lead to the extinction of the human race, they most certainly cause immense suffering to man and beast. Air and water pollution, pesticides, deforestation, fossil fuels etc. all contribute even now to the suffering and premature deaths of huge numbers of humans, and to my mind it is totally irresponsible for any politician to pretend that we do not already have a crisis on our hands because of human interference with nature. I have been greatly encouraged, however, by the efforts of the younger generation to make the environment a priority concern for all governments.
Excellent comment and review. I'll give one brief example of future trouble, river dams. All water carry silt which builds up behind all dams. Dredging behind dams is very expensive. All dams have a natural life, perhaps over many centuries, but a reckoning is coming.
Sixth extinction? One is newly identified
by David Turell , Monday, September 09, 2019, 20:44 (1690 days ago) @ David Turell
Not the current times blaming humans but a newly found old one, caused by volcanoes:
https://www.sciencedaily.com/releases/2019/09/190909105555.htm
"A team of scientists has concluded that earth experienced a previously underestimated severe mass-extinction event, which occurred about 260 million years ago, raising the total of major mass extinctions in the geologic record to six.
***
"'Notably, all six major mass extinctions are correlated with devastating environmental upheavals -- specifically, massive flood-basalt eruptions, each covering more than a million square kilometers with thick lava flows."
"Scientists had previously determined that there were five major mass-extinction events, wiping out large numbers of species and defining the ends of geological periods: the end of the Ordovician (443 million years ago), the Late Devonian (372 million years ago), the Permian (252 million years ago), the Triassic (201 million years ago), and the Cretaceous (66 million years ago). And, in fact, many researchers have raised concerns about the contemporary, ongoing loss of species diversity -- a development that might be labeled a "seventh extinction" because such a modern mass extinction, scientists have predicted, could end up being as severe as these past events.
"The Historical Biology work, which also included Nanjing University's Shu-zhong Shen, focused on the Guadalupian, or Middle Permian period, which lasted from 272 to about 260 million years ago.
"Here, the researchers observe, the end-Guadalupian extinction event -- which affected life on land and in the seas -- occurred at the same time as the Emeishan flood-basalt eruption that produced the Emeishan Traps, an extensive rock formation, found today in southern China. The eruption's impact was akin to those causing other known severe mass extinctions, Rampino says.
"'Massive eruptions such as this one release large amounts of greenhouse gases, specifically carbon dioxide and methane, that cause severe global warming, with warm, oxygen-poor oceans that are not conducive to marine life," he notes.
"In terms of both losses in the number of species and overall ecological damage, the end-Guadalupian event now ranks as a major mass extinction, similar to the other five," the a'uthors write."
Comment: obviously a very stable environment is of most importance, for life to survive. The Earth has many protecting feed-back cycles.
Sixth extinction? One is newly identified
by David Turell , Wednesday, September 16, 2020, 20:26 (1317 days ago) @ David Turell
This is newly identified as a mass extinction:
https://phys.org/news/2020-09-discovery-mass-extinction.html
"...an international team has identified a major extinction of life 233 million years ago that triggered the dinosaur takeover of the world. The crisis has been called the Carnian Pluvial Episode.
***
"The cause was most likely massive volcanic eruptions in the Wrangellia Province of western Canada, where huge volumes of volcanic basalt was poured out and forms much of the western coast of North America.
"'The eruptions peaked in the Carnian," says Jacopo Dal Corso. "I was studying the geochemical signature of the eruptions a few years ago and identified some massive effects on the atmosphere worldwide. The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming".The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about 1 million years in all. The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems. The shifts in climate encouraged growth of plant life, and the expansion of modern conifer forests.
"'The new floras probably provided slim pickings for the surviving herbivorous reptiles," said Professor Mike Benton. "I had noted a floral switch and ecological catastrophe among the herbivores back in 1983 when I completed my Ph.D. We now know that dinosaurs originated some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit. It was the sudden arid conditions after the humid episode that gave dinosaurs their chance."
"It wasn't just dinosaurs, but also many modern groups of plants and animals also appeared at this time, including some of the first turtles, crocodiles, lizards, and the first mammals.
***
"'So far, palaeontologists had identified five "big" mass extinctions in the past 500 million yeas of the history of life," says Jacopo Dal Corso. "Each of these had a profound effect on the evolution of the Earth and of life. We have identified another great extinction event, and it evidently had a major role in helping to reset life on land and in the oceans, marking the origins of modern ecosystems.'"
Comment: It follows a previous pattern wiping out large groups and allowing new ones to appear. Each event advances the complexity of life. That can't be chance but purposeful.