- 2875 - EARTH - climate change got us here? A coupled increase in atmospheric CO2 and decrease in surface ocean pH, global warming, changes in productivity and oxygen depletion have been reported worldwide, which suggests that the scenario outlined here may be relevant to understanding future environmental and climatic trends.
--------------------------- 2875 - EARTH - climate change got us here?
- Humanity is at the pinnacle of evolution on Earth as things stand now. But it took an awfully long time for evolution to produce beings such as you and me, and all the other animals that occupy this planet. Several times, all life had to drag itself back from near annihilation.
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- The largest extinction setback was the Permian-Triassic extinction, also called the “Great Dying,” some 252,000,000 years ago. Up to 96% of all marine species and 70% of terrestrial vertebrate species went extinct. But, some our ancestors survived.
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- There’s some uncertainty surrounding the cause or causes of the extinction. Many of the usual suspects have been accused: impact events, climate change brought on by methane-producing bacteria, massive volcanic eruptions, as well as some lesser-known potential causes like a fungal spike.
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- There’s some evidence for each hypothesis, but it’s still controversial. The uncertainty around the Great Dying also extends to the timeline and sequence of events, including how long Earth took to recover. There is also uncertainty with who came up with this master plan?
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- We have learned more about extinctions. Research has provided the first precise reconstruction of the carbon source and with it the trigger of the crisis, as well as uncovers the subsequent chain of processes that resulted in Earth’s largest mass extinction.
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- The research focuses on “brachiopod” fossils, which haven’t received much attention and are sometimes overlooked. Brachiopods are a group of creatures that have hard shells on their upper and lower surfaces. They’re different from bivalve molluscs like clams, which have shells on the sides. Brachiopods are still around today, but are far less numerous than they were in the Paleozoic.
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- The researchers studied brachiopod shells from Italy and China and the Siberian Traps, the source of the CO2. Many brachiopod species went extinct during this Great Dying. But some survived, and the team of researchers found brachiopod shells that span the critical time period during the Permian-Triassic extinction event.
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- The shells are a record over time of the ocean’s pH level. The pH level reflects the amount of absorbed carbon dioxide (CO2) in the ocean when the animal made the shell. When combined with carbon isotope constraints, the team was able to construct a timeline of not only the amount of atmospheric CO2 but also their sources at the time of the extinction.
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- The researchers determined that a large pulse of CO2 triggered the Permian-Triassic extinction. The pulse originated in Siberia, where a huge volcanic eruption created a massive flood basalt province. All of that activity released an enormous amount of CO2 into the atmosphere; 100,000 billion tons ------- (10^14 tons).
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- That is an almost incomprehensible amount of carbon injected into the atmosphere in a short (geologically speaking) period of time. It is more than 40 times the amount of all carbon available in modern fossil fuel reserves including carbon already burned since the industrial revolution.
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- All of that CO2 threw Earth’s biogeochemical makeup out of balance and spelled doom for most of the species on Earth. The Siberian Traps released an enormous amount of CO2 into the atmosphere, acidifying the oceans and extinguishing marine life in the surface ocean.
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- The CO2 led to extreme warming of the Earth’s atmosphere and lethal acidification of the oceans. For marine animals that build their own shells, like the brachiopods at the heart of this research, it was devastating.
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- As the ocean became more acidic, the carbonate that they need to build shells becomes unavailable, locked into the ocean’s new chemistry. Some brachiopods survived, creating the evidential record that enabled this study.
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- The extreme climate warming was the second severe blow for life on Earth. The greenhouse effect created pronounced changes in weathering on the land, and on nutrient input and cycling in the ocean. The result was vast deoxygenation of the Earth’s oceans. It likely also poisoned the oceans with sulfides, killing other groups of organisms.
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- The oceans, birthplace of life on Earth, became a place of death. The amount of dissolved oxygen in the oceans plunged rapidly in intermediate depths and in the deep ocean. The plunge wasn't so pronounced at the surface, where interaction with the atmosphere introduced oxygen into the ocean. This deoxygenation spelled doom for many species.
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- The amount of dissolved oxygen in the oceans plunged rapidly in intermediate depths and in the deep ocean. The plunge wasn’t so pronounced at the surface, where interaction with the atmosphere introduced oxygen into the ocean. The deoxygenation spelled doom for many species.
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- Life on Earth relies on global cycles of nutrients, carbon, nitrogen, and other things. In only a few thousand years, those cycles were upended by the CO2 from the Siberian eruptions.
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- Climate warming, ocean acidification, ocean deoxygenation, and sulfide poisoning came one after another, creating the most severe extinction in the Earth’s history.
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- The Permian-Triassic Boundary mass extinction was a cascading marine collapse, triggered by a multi-millennial-scale voluminous injection of carbon to the atmosphere by the emplacement of Siberian Traps sill intrusions. It is a magnitude that profoundly altered the biogeochemical processes and set off a chain of events that selectively eliminated different groups of marine organisms.
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- It took several hundreds of thousands to millions of years for the ecosystem to recover from the catastrophe, which profoundly altered the course of evolution of life on Earth.
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- It’s natural to wonder if these findings can tell us anything about our current predicament, where our own carbon emissions are warming the climate and acidifying the oceans.
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- We may still be emitting more carbon than during the Siberian volcanic activity that triggered the Permian-Triassic extinction. It is noteworthy that even the peak emissions rate during the largest known mass extinction is still more than 14 times less than the current anthropogenic rate.
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- During the Great Dying, it took thousands of years for the effects of all of that carbon to unfold. But we’re already seeing the effects of our carbon emissions, and we’re barely out of the Industrial Revolution.
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- A coupled increase in atmospheric CO2 and decrease in surface ocean pH, global warming, changes in productivity and oxygen depletion have been reported worldwide, which suggests that the scenario outlined above may be relevant to understanding future environmental and climatic trends.
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----------------------------- Other reviews available upon request:
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- 2869 - EARTH - waster, water everywhere? There remains a number of mysteries on our planet including the elusive origin of the blue water on the Earth. Scientists have found the interstellar organic matter could produce an abundant supply of water by heating, suggesting that “organic matter” could be the source of terrestrial water.
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- 2486 - EARTH - Third Rock from the Sun. The Sun’s energy itself is changing in its light energy. It has several cycles of its own , “Could Our Sun Be a Variable Star?” . Today we are considered to be in a normal warming trend. Global warming is claimed to be exacerbating this warming trend with human burning of fossil fuels and putting greenhouse gases into the atmosphere.
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- 2441 - EARTH - an Amazing Place? These are interesting facts about Mother Earth. Some are so amazing they are hard to comprehend. You lucked out! The hottest on Earth occurred September 13, 1922 when it was 136 F in El Azizia, Libya.
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- 2383 - EARTH - measurements from the Ice Satellite. Satellites are busy measuring the elevations around the Earth with great precision. More than a trillion new measurements of Earth's height have been made from glaciers in Greenland, to mangrove forests in Florida, to sea ice surrounding Antarctica
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- 2033 - The Earth is doomed. Also lists 10 more reviews about the Earth, an amazing place to live.
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- 1785 - Earth from Space Station. How many times does the Earth rotate while making a single orbit around the Sun?
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- 1721 - Closest stars and more perfect Earth’s? A star just 7 lightyears away was newly discovered. Our Earth is right at the edge of a habitable planet. There are more life friendly habitable zones for planets around other stars.
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- 1401 - 2 Satellites are making a gravity map of the Earth and finding that our groundwater is disappearing. In March 2002 science launched 2 satellites. 310 miles up, one following the other by 140 miles. There was a precision microwave transmitter and receiver installed that linked the two together to precisely measure the distance between them. The accuracy of the range measurement was to within 10 micrometers, 0.001 centimeters.
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- 1295 - how the Earth was formed? Nostalgia ain’t what it used to be and the night sky is not what you see. What you see is a lot younger that what is. The light you see left years ago, thousands, millions, even billions of years ago depending on what you are looking at. What it is today is totally different but you are prevented from seeing it because the light has not reached us yet
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- 1256 - Why Do I Have Earthquake Insurance? The Pacific Tectonic plate has been moving lately. Chile received an 8.8 Magnitude in February, Christchurch, New Zealand a 6.3 in February, Japan a 9.0 in March. Earthquakes appear to occur in bunches since 1900. Here is a review of record and predictions for the future.
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- 1190 - Thank your children for all the resource you consume.
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- 537 - The Garden of Eden
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- 511 - The density of the Earth?
- 382 - Could Our Sun Be a Variable Star?
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- 381 -- Our Closest Star
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- 533 - Why the Sun will become a White Dwarf
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- October 24, 2020 2875
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--- Some reviews are at: -------------- http://jdetrick.blogspot.com -----
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--- to: ------ jamesdetrick@comcast.net ------ “Jim Detrick” -----------
--------------------- --- Sunday, October 25, 2020 ---------------------------
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