Life thrived on Earth 3.5 billion years ago, research suggests

Scientists use stable sulfur isotopes to understand ancient microbial metabolism

Date:
February 8, 2019
Source:
Tokyo Institute of Technology
Summary:
Three and a half billion years ago Earth hosted life, but was it barely surviving, or thriving? A new study provides new answers to this question. Microbial metabolism is recorded in billions of years of sulfur isotope ratios that agree with this study’s predictions, suggesting life throve in the ancient oceans. Using this data, scientists can more deeply link the geochemical record with cellular states and ecology.

Electron microscopy image of microbial cells which respire sulfate.
Credit: Guy Perkins and Mark Ellisman, National Center for Microscopy and Imaging Research

Three and a half billion years ago Earth hosted life, but was it barely surviving, or thriving? A new study carried out by a multi institutional team with leadership including the Earth-Life Science Institute (ELSI) of Tokyo Institute of Technology (Tokyo Tech) provides new answers to this question. Microbial metabolism is recorded in billions of years of sulfur isotope ratios that agree with this study’s predictions, suggesting life throve in the ancient oceans. Using this data, scientists can more deeply link the geochemical record with cellular states and ecology.

Scientists want to know how long life has existed on Earth. If it has been around for almost as long as the planet, this suggests it is easy for life to originate and life should be common in the Universe. If it takes a long time to originate, this suggests there were very special conditions that had to occur. Dinosaurs, whose bones are presented in museums around the world, were preceded by billions of years by microbes. While microbes have left some physical evidence of their presence in the ancient geological record, they do not fossilize well, thus scientists use other methods for understanding whether life was present in the geological record.

Presently, the oldest evidence of microbial life on Earth comes to us in the form of stable isotopes. The chemical elements charted on the periodic are defined by the number of protons in their nuclei, for example, hydrogen atoms have one proton, helium atoms have two, carbon atoms contain six. In addition to protons, most atomic nuclei also contain neutrons, which are about as heavy as protons, but which don’t bear an electric charge. Atoms which contain the same number of protons, but variable numbers of neutrons are known as isotopes. While many isotopes are radioactive and thus decay into other elements, some do not undergo such reactions; these are known as “stable” isotopes. For example, the stable isotopes of carbon include carbon 12 (written as 12C for short, with 6 protons and 6 neutrons) and carbon 13 (13C, with 6 protons and 7 neutrons).

All living things, including humans, “eat and excrete.” That is to say, they take in food and expel waste. Microbes often eat simple compounds made available by the environment. For example, some are able to take in carbon dioxide (CO2) as a carbon source to build their own cells. Naturally occurring CO2 has a fairly constant ratio of 12C to 13C. However, 12CO2 is about 2 % lighter than 13CO2, so 12CO2 molecules diffuse and react slightly faster, and thus the microbes themselves become “isotopically light,” containing more 12C than 13C, and when they die and leave their remains in the fossil record, their stable isotopic signature remains, and is measurable. The isotopic composition, or “signature,” of such processes can be very specific to the microbes that produce them.

Besides carbon there are other chemical elements essential for living things. For example, sulfur, with 16 protons, has three naturally abundant stable isotopes, 32S (with 16 neutrons), 33S (with 17 neutrons) and 34S (with 18 neutrons). Sulfur isotope patterns left behind by microbes thus record the history of biological metabolism based on sulfur-containing compounds back to around 3.5 billion years ago. Hundreds of previous studies have examined wide variations in ancient and contemporary sulfur isotope ratios resulting from sulfate (a naturally occurring sulfur compound bonded to four oxygen atoms) metabolism. Many microbes are able to use sulfate as a fuel, and in the process excrete sulfide, another sulfur compound. The sulfide “waste” of ancient microbial metabolism is then stored in the geological record, and its isotope ratios can be measured by analyzing minerals such as the FeS2 mineral pyrite.

This new study reveals a primary biological control step in microbial sulfur metabolism, and clarifies which cellular states lead to which types of sulfur isotope fractionation. This allows scientists to link metabolism to isotopes: by knowing how metabolism changes stable isotope ratios, scientists can predict the isotopic signature organisms should leave behind. This study provides some of the first information regarding how robustly ancient life was metabolizing. Microbial sulfate metabolism is recorded in over a three billion years of sulfur isotope ratios that are in line with this study’s predictions, which suggest life was in fact thriving in the ancient oceans. This work opens up a new field of research, which ELSI Associate Professor Shawn McGlynn calls “evolutionary and isotopic enzymology.” Using this type of data, scientists can now proceed to other elements, such as carbon and nitrogen, and more completely link the geochemical record with cellular states and ecology via an understanding of enzyme evolution and Earth history.

Advertisements

Dinosaur-Killing Asteroid Triggered Mile-High Tsunami That Spread Through Earth’s Oceans

Dinosaur-Killing Asteroid Triggered Mile-High Tsunami That Spread Through Earth's Oceans

Credit: Shutterstock

When the dinosaur-killing asteroid collided with Earth more than 65 million years ago, it did not go gently into that good night. Rather, it blasted a nearly mile-high tsunami through the Gulf of Mexico that caused chaos throughout the world’s oceans, new research finds.

The 9-mile-across (14 kilometers) space rock, known as the Chicxulub asteroid, caused so much destruction, it’s no wonder the asteroid ended the dinosaur age, leading to the so-called Cretaceous-Paleogene (K-Pg) extinction.

“The Chicxulub asteroid resulted in a huge global tsunami, the likes of which have not been seen in modern history,” said lead researcher Molly Range, who did the research while getting her master’s degree in the Department of Earth and Environmental Sciences at the University of Michigan. [Image Gallery: Ancient Monsters of the Sea]

Range and her colleagues presented the research, which has yet to be published in a peer-reviewed journal, at the American Geophysical Union’s annual meeting on Dec. 14 in Washington, D.C. And the research, first reported by EOS, is novel. “As far as we know, we are the first to globally model the tsunami from impact to the end of wave propagation,” Range told Live Science.

The idea for the project got started when Range’s two advisors — Ted Moore and Brian Arbic, both in the Department of Earth and Environmental Sciences at the University of Michigan — realized there was a glaring gap in the Chicxulub research field. Mainly, no one had published a global simulation of the tsunami the asteroid created.

“It wasn’t until starting this project that I realized the actual scale of this tsunami, and it’s been a fun research story to share,” Range said.

The researchers knew that the asteroid hit shallow water in the Gulf of Mexico. But to correctly model its huge impact, they needed a model that could compute “the large scale deformation of the [Earth’s] crust that formed the crater, as well as the chaotic waves from the initial blast of water away from the impact site, and waves from ejecta falling back into the water,” Range said. So, the group turned to Brandon Johnson, an assistant professor who studies impact cratering at Brown University in Rhode Island.

Johnson ran a model detailing what happened in the 10 minutes following the impact, when the crater was nearly a mile deep (1.5 kilometers) and the blast was so powerful, there wasn’t any water in the crater yet. “At this point, some water was moving back toward the crater,” Range said. According to the model, “this water will then rush into the crater and then back out, forming the ‘collapse wave.'”

In a second model, the team studied how the tsunami propagated through oceans around the world. They did this by taking the results from the first model (particularly the crater shape) and the impact’s waves with respect to resting sea level and water speeds, Range said. They then used data sets on the ancient terrain of the ocean, and used that to determine how the tsunami would have played out.

The results show the effects of the tsunami were felt all around the world. [In Pictures: Japan Earthquake & Tsunami]

“We found that this tsunami moved throughout the entire ocean, in every ocean basin,” Range said. In the Gulf of Mexico, water moved as fast as 89 mph (143 km/h), she found. Within the first 24 hours, the effects of the tsunami’s impact spread out of the Gulf of Mexico and into the Atlantic, as well as through the Central American seaway (which doesn’t exist anymore, but used to connect the Gulf to the Pacific).

After the initial nearly mile-high (1.5 km) wave, other huge waves rocked the world’s oceans. In the South Pacific and North Atlantic, waves reached a whopping maximum height of 46 feet (14 m). In the North Pacific, they reached 13 feet (4 m). Meanwhile, the Gulf of Mexico saw waves as high as 65 feet (20 meters) in some spots and 328 feet (100 m) in others.

To put that in perspective, the largest modern wave ever recorded in the Southern Hemisphere was a “measly” 78 feet (23.8 m) tall, which struck near New Zealand in May 2018, Live Science previously reported.

There’s evidence that supports the models, Range said. According to the second model, fast-moving water from the impact likely caused erosion and sediment disruption in South Pacific, North Atlantic and Mediterranean ocean basins.

In a separate study (which also has yet to be published), Moore examined sediment records across the ocean. His findings agree with the tsunami model, Range said.

It can be hard to imagine such a cataclysmic tsunami, so the researchers compared it to the 2004 Indian Ocean tsunami that killed at least 225,000 people. The two tsunamis were as different as night and day, they found. “Over the first 7 hours of both tsunamis, the [Chicxulub] impact tsunami was 2,500 to 29,000 times greater in energy than the 2004 Indian Ocean tsunami,” Range said.

Of course, the giant tsunami wasn’t the only event that did in the non-avian dinosaurs. The asteroid also triggered shock waves and sent a vast amount of hot rock and dust into the atmosphere, which rubbed together with so much friction that they started forest fires and cooked animals alive. These particles also hovered in the atmosphere and blocked the sun’s rays for years, killing plants and the animals that ate them.

Originally published on Live Science.

‘There is little we can do’ Scientist’s SHOCK Yellowstone revelation over human EXTINCTION

A GEOPHYSICIST has offered a chilling warning over the Yellowstone volcano, it was revealed during a bombshell BBC documentary.

Yellowstone: Expert issues WARNING about supervolcano

Pause

Unmute

Current Time 0:30
/
Duration 0:45
Loaded: 0%

Progress: 0%

FacebookTwitterShareFullscreen

Robert Smith is a leading lecturer at the University of Utah, who has years of experience in natural disasters, including his study into Yellowstone. The supervolcano, located in Yellowstone National Park, has erupted three times in history, 2.1 million years ago, 1.2 million years ago and 640,000 years ago. However, a fourth eruption could have dire consequences, according to Dr Smith.

He revealed during a 2015 BBC documentary titled “Supervolcano” how another eruption could prove fatal to humanity.

He said: “If another eruption was to occur, I think there is little man can do about it.

“The biggest thing we can do now is understand them.”

PROMOTED STORY

The last eruption of Yellowstone produced around 2,500 times more volcanic material than the 1980 eruption of Mount St Helens.

Yellowstone could see the end of human life

Yellowstone could see the end of human life (Image: GETTY)

Robert Smith

Robert Smith made the shocking revellation (Image: WIKI)

If another eruption was to occur, I think there is little man can do about it

Robert Smith

Geologists have warned that, once a triggering event takes place, an eruption could happen in as little as two weeks.

Jacob Lowenstern, a researcher with the US Geological Survey in Vancouver, Washington, detailed how the last catastrophic incident may have played out during the same documentary.

He said: “Typically when these eruptions begin, they begin from a certain event, then they get larger as they move along the fracture system.

“The entire sequence that formed the last Yellowstone eruption may have taken as little as two weeks.”

This created an eruptive column so colossal that it covered about 60 per cent of the US in a thick layer of ash.

Yellowstone Volcano sits below the national park

Yellowstone Volcano sits below the national park (Image: GETTY)

Yellowstone volcano is a threat to the whole world

Yellowstone volcano is a threat to the whole world (Image: GETTY)

Should the same happen again, the ground around Yellowstone National Park would rise upwards forming a swarm of earthquakes.

Then, following the eruption, enormous pyroclastic flows would blast their way across the park.

This mixture of ash, lava blebs, and superheated gas exceed temperatures of 1,000C and can move at speeds of up to 300mph.

They are predicted to spread more than 100 miles out from Yellowstone, burying states like Wyoming, Montana, Idaho, and Colorado in three feet of harmful volcanic ash.

If the pyroclastic flow hits anyone, they would possibly die within seconds as the air could heat up to around 300C.

These Animal Species Went Extinct In 2018

NEWS

The Poʻo-uli

Advertisement

Proliferating on our planet for millions of years, these animals could no longer be seen in the coming years as 2018 has proved to be a year of extinction for these animal species. For instance, three bird species went extinct this year, scientists said, two of which are songbirds from north-eastern Brazil namely, The Cryptic Treehunter and Alagoas Foliage-gleaneraccording to a report from the conservation group Birdlife International.

Related: The Three Ways The Universe Might End

According to Birdlife, the other extinct bird is Hawaii’s Po’ouli, which has not been seen in the wild since 2004, the year in which the last captive bird died. An important disturbing fact is that mainland species are starting to go extinct, rather than island species.

The Poʻo-uli

Advertisement

Image Source: Wikimedia

According to Stuart Butchart, BirdLife’s chief scientist and lead author on the paper, “Ninety per cent of bird extinctions in recent centuries have been of species on islands, “However, our results prove that there is a growing wave of extinctions sweeping across the continents, driven mainly by habitat loss and degradation from unsustainable agriculture and logging,” he said.

Related: Astounding fact about Orangutans: The Only Non-Human Primates Who Can Talk About The Past

An additional species of bird that reached the verge of extinction in 2018 is the Spix’s macaw, which was declared extinct in the wild and now only a few captive Spix’s macaws are alive. This species was wiped out in the wild because of deforestation and other factors such as the creation of a dam and trapping for wild trade. A few other bird species which are at the verge of extinction include New Caledonian Lorikeet and the Pernambuco Pygmy-owl. Beyond birds, other animals such as the vaquita, a dolphin-like porpoise and the northern white rhino are also heading towards extinction.

Spix's macaws

Image Source: Wikimedia

According to the National Oceanic and Atmospheric Administration, “Vaquitas are the foremost vulnerable of the world’s marine mammals,” “Less than thirty vaquitas remain in the wild, and trap in gill nets is driving the species toward extinction.” Also, the last male northern white rhino died at a wildlife sanctuary in Kenya last March according to a recent report. Now, only two females are left. According to a report discharged last year by the U.S. Fish and Wildlife Service, only forty endangered red wolves are left wild in the USA, and the population might go extinct within eight years. Earth “is currently within the thick of its sixth mass extinction of plants and animals – the sixth wave of extinctions in the past half-billion years,” according to the Centre for Biological Diversity.

Related: 10 New Plant Species Discovered in 2018

Northern White Rhino

“We are presently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago,” they added.

Indeed, extinction is a natural phenomenon and it occurs at a natural ‘background’ rate of about one to five species per year. Scientists estimate that the rate of losing species is 1,000 to 10,000 times the background rate.” In the past 500 years, the centre estimates that about 1,000 species have gone extinct, ranging from the woodland bison of West Virginia and Arizona’s Merriam’s elk to the Rocky Mountain grasshopper, passenger pigeon and Puerto Rico’s Culebra parrot.

Source: Mashable

How Trump’s Wall Would Alter Our Biological Identity Forever

 

https://blogs.scientificamerican.com/observations/how-trumps-wall-would-alter-our-biological-identity-forever/?utm_medium=social&utm_content=organic&utm_source=facebook&utm_campaign=SciAm_&sf205243874=1

It would destroy an extraordinary web of biodiversity that evolved over millions of years

How Trump's Wall Would Alter Our Biological Identity Forever
Credit: Sandy Huffaker Getty Images

It’s no secret that the Trump administration is attacking science. From scrubbing the words “climate change” from federal agency websites to cutting public health programs in the Environmental Protection Agency to burying its own climate report involving more than 300 leading climate scientists, President Donald Trump and his appointees take well-established scientific facts and treat them like science fiction. One environmental attack is particularly appalling, but headlines have focused more on its political theatrics than on its catastrophic consequences for North American biodiversity: building the wall along the U.S.-Mexico border. As a scientist who understands the implications of this decision for wildlife, I am astounded and outraged that such a precious biological treasure is being sacrificed for political gain. And I am not alone.

Earlier this year, my colleagues at Defenders of Wildlife and I led more than 2,500 scientists from around the world in declaring consensus over the impending consequences of the border wall on North America’s biodiversity in a synthesis study published in BioScience. In an exceptional moment of unity, we scientists agree with the irrefutable evidence that the border wall is a rampant ecological disaster. This is notable because consensus is rare among scientists. When scientific consensus does exist—as with climate change—it’s a wake-up call that business as usual is likely to result in catastrophe.

While the border wall has critical implications for human migration and international relations, this physical barrier is also an ecological nightmare. As it divides communities where millions of people live, the border wall also cuts through the habitats of over 1,500 wildlife species. As they evolved through time, these species developed specific characteristics to thrive in the ecologically diverse landscapes along the border, ranging from extreme desert scrublands to rain-heavy wetlands. Many eked out a living by tracking rare resources along north-south migratory routes by land and air. The breadth of species that thrive in this ecological marvel make the borderlands one of the most biologically rich regions in the world, and an internationally acclaimed conservation hotspot.

While campaigning for office, Trump riled up his supporters with promises of a “great, great wall on our southern border,” one that will divide the complex biological mosaic of the Southwest. But large parts of our border with Mexico are already walled off. The Department of Homeland Security (DHS) has already constructed 600 miles of blockades without regard for impacts to the region’s previous biodiversity, using the 2005 Real ID Act to sidestep bedrock environmental protection laws like the Endangered Species Act (ESA) with no chance for public engagement.

This 600-mile stretch of wall is an unclimbable barricade for 346 nonflying animal species, not to mention flighted species like the endangered Quino checkerspot butterfly and the threatened and endangered ferruginous pygmy-owl that cannot fly high enough to surmount the wall. Without passage, animals cannot disperse to new populations to spread their genes, potentially leading to genetic inbreeding akin to the plight of the African cheetah. During natural seasonal flooding, the wall traps flood waters and kills wildlife and vegetation. During natural disasters like heat waves, when water or food on one side of the wall is not available, those species will be left to perish, unable to access resources on the other side.

But the border wall is much more than just a physical wall. Massive construction vehicles drag building supplies through delicate habitat, and light and noise pollution disturb and displace diurnal and nocturnal species. Once built, security vehicles patrol along miles of paved and unpaved roads and extensive networks of undesignated off-road paths, all of which expand the barren footprint of the wall.

These pervasive impacts will not be recognized, assessed or addressed, because the Trump administration has waived dozens of laws in New Mexico, Texas and California designed to protect plants, animals and humans. These are laws that Congress passed, and which the American people wholeheartedly support to safeguard our environmental and public health. With these laws ignored, wall construction proceeds—at this very moment—without environmental impact analysis, mitigation, public input or protection of legal action.

Besides the 600 miles installed, there may be 1,953 miles of border wall yet to come. In one generation, humans will have successfully disintegrated an extraordinary biodiversity web that evolved over millions of years. It is a legacy of which we should not be proud. Building the border wall sacrifices the ancient biodiversity of North America for the momentary political gain of one president. Our biodiversity is less flexible, requiring millions of years to evolve to its intricate state of ecological intactness. Further construction of the U.S.-Mexico border wall will undoubtedly lead to the death of countless species in the process—adding to the 10 million species marching towards extinction worldwide as a result of the broader human footprint.

But there is hope. Biodiversity is resilient, and we can reverse this biodiversity crisis if we act now. Congress can still defund the wall, support flexible barriers or technology measures that consider the needs of biodiversity, and require the DHS to comply with U.S. laws to assess and address environmental impacts. We live in an age with technological capabilities to keep people safe without sacrificing wildlife, wild places and fellow humans. Let us apply our innovative minds to this worthwhile task.

Let us not compromise thousands of species and a rare biodiversity hotspot, alongside the identity of millions of people along the border, for reprehensible campaign promises and political theatrics that will only further divide us.


This is what I’m worried about:

https://www.vox.com/energy-and-environment/2017/4/10/14471304/trump-border-wall-animals?fbclid=IwAR1eip8E_iKQHKQWZ4WE8op45zsL2kQg4S1FX5ZJvf9Hn4mf7zcfheJOn9I

These species went extinct in 2018. More may be doomed to follow in 2019.

LINKEDINCOMMENTMORE

They’ve been on our planet for millions of years, but 2018 was the year several species officially vanished forever.

Three bird species went completely extinct this year, scientists say, two of which are songbirds from northeastern Brazil: The Cryptic Treehunter (Cichlocolaptes mazarbarnetti) and Alagoas Foliage-gleaner (Philydor novaesi), according to a recent report from the conservation group BirdLife International.

According to BirdLife, the other extinct bird is Hawaii’s Poo-uli (Melamprosops phaeosoma), which has not been seen in the wild since 2004 (the same year the last captive bird died).

A disturbing trend is that mainland species are starting to go extinct, rather than island species: “Ninety percent of bird extinctions in recent centuries have been of species on islands,” said Stuart Butchart, BirdLife’s chief scientist and lead author on the paper.

“However, our results confirm that there is a growing wave of extinctions sweeping across the continents, driven mainly by habitat loss and degradation from unsustainable agriculture and logging,” he said.

More: Humans have killed off most of Earth’s big mammals. In 200 years, cows could be biggest ones left.

More: Red wolves nearing extinction — only 40 left in the wild

An additional species of bird – the Spix’s macaw, which was made famous in the 2011 animated movie Rio – has been declared extinct in the wild. Only a few dozen captive Spix’s macaws are alive today.

That species was wiped out in the wild because of deforestation and other factors such as the creation of a dam and trapping for wild trade.

A few other bird species that are near extinction have such exotic names as the New Caledonian Lorikeet and the Pernambuco Pygmy-owl.

Beyond birds, other animals such as the vaquita (a dolphin-like porpoise) and the northern white rhino are also near the end.

“Vaquitas are the most endangered of the world’s marine mammals,” the National Oceanic and Atmospheric Administration said. “Less than 30 vaquitas remain in the wild, and entanglement in gill nets is driving the species toward extinction.”

The last male northern white rhino died at a wildlife sanctuary in Kenya last March, Mashable reported. Only two females are left. 

Here in the U.S., only 40 endangered red wolves remain in the wild in the U.S., and the population could go extinct within eight years, according to a report released earlier this year by the U.S. Fish and Wildlife Service.

Earth “is now in the midst of its sixth mass extinction of plants and animals — the sixth wave of extinctions in the past half-billion years,” according to the Center for Biological Diversity.

The group said “we’re currently experiencing the worst spate of species die-offs since the loss of the dinosaurs 65 million years ago.

“Although extinction is a natural phenomenon, it occurs at a natural “background” rate of about one to five species per year. Scientists estimate we’re now losing species at 1,000 to 10,000 times the background rate.”

In the past 500 years, the center estimates that about 1,000 species have gone extinct, from the woodland bison of West Virginia and Arizona’s Merriam’s elk to the Rocky Mountain grasshopper, passenger pigeon and Puerto Rico’s Culebra parrot.

LINKEDINCOMMENTMORE

Earth Has Seen CO2 Spike Before. It Didn’t End Well.

https://www.bloomberg.com/opinion/articles/2018-12-20/my-15-favorite-nonfiction-books-of-2018

It’s unclear exactly what happened 252 million years ago as the planet warmed, but 90 percent of species went extinct.

Humans might avoid their fate. Especially if an asteroid helps out.

Photographer: Dan Kitwood/Getty Images

Asteroid impacts used to be science popularizers’ favorite existential threat, but space rocks have been displaced by atmospheric carbon. This is not just fashion but the result of a new reading of our planet’s past.

In the 1990s, scientists thought asteroid impacts had triggered five mass extinctions, including the extinction of the dinosaurs 65 million years ago. Now, they’ve come to realize that the other four of the Earth’s mega-disasters probably came from within — triggered by belches of carbon into the atmosphere and oceans.

The worst of the five was an event called the end-Permian. It started with volcanic eruptions, which ignited carbon-rich sediments, infusing the atmosphere with a jolt of new carbon dioxide. Within a few thousand years, more than 90 percent of species went extinct.

Some people present this as a cautionary tale. Is that reasonable? It happened 252 million years ago, and the temperature rose more than the worst-case projections for fossil-fuel-induced global warming. On the other hand, it was a pretty good proof of principle.

The principle isn’t just that increasing carbon dioxide makes things get hot, but that fast changes in ocean and atmospheric chemistry can trigger a reordering of the living world. That in turn causes more chemical changes, leading to cascading changes in the biosphere. In the end-Permian, there was a collapse of plankton and fish and an explosion of bacteria that emit sulfur compounds and possibly others that exhale heat-trapping methane.

Seth Burgess, a United States Geological Survey geologist who studies the end-Permian, said there are two intriguing puzzles — the trigger mechanism and the kill mechanism. There’s a general agreement that the trigger was, in part, volcanic activity giving rise to an igneous formation called the Siberian Traps. But the eruptions alone couldn’t have released enough greenhouse gases to cause the estimated 10-15 degree Celsius rise in global temperature.

He’s proposed that the magma cooked vast carbon-rich sediments, releasing much more carbon into the atmosphere. As for the kill mechanism, the heat alone isn’t enough, so people have proposed various ways chemistry and biology went haywire. A new paper, published in Science this month, points to plummeting oxygen levels in the oceans. The conclusion comes from a study of which organisms died off and where.

The paper adds weight to an idea put forward a few years ago by Lee Kump of Penn State, a researcher I interviewed for a column back in 2011. Kump said that oxygen starvation killed some organisms, and left open niches for others to flourish. During the end-Permian, chemical traces suggest, green sulfur bacteria proliferated, gassing other living things with toxic hydrogen sulfide.

In his book “Under a Green Sky,” paleontologist Peter Ward used Kump’s idea to describe the world as it would have been just after the end-Permian: “Most of the shoreline is encrusted with rotting organic matter. Silk-like swaths of bacterial slick now putrefying under the blazing sun … from shore to the horizon there is a vast, flat, oily purple. … No fish break its surface. No birds. … We are under a pale green sky and it has the smell of death and poison.”

It sounds weird and cool, as long as this stays safely in the past, or we’re talking about someone else’s planet. But here we are on a warming Earth. Could the green sky and smell of death possibly be in our future as well?

MIT geophysics professor Daniel Rothman said he was initially skeptical. He’d read “The Sixth Extinction” by Elizabeth Kolbert, and wondered how she knew that climate change would cause another mass extinction. The Earth’s atmospheric carbon has gone up and down over geologic history, and only four times has mass extinction followed.

Rothman looked at 31 periods when atmospheric carbon rose, most of which didn’t have a big effect on the biosphere. When changes were big but happened slowly, life had a chance to adjust. If they happened fast but amounted to only a small carbon increase, life could go on as before.

Last year, Rothman came up with a formula based on both the rate and total amount of added carbon, and demonstrated that it predicted which of those 31 periods would lead to catastrophe. According to his formula, our current rate of emissions is extremely high, but it won’t cause a mass extinction unless our total emissions add 310 gigatons of carbon to the oceans. He published the results in Science Advances.

The UN’s Intergovernmental Panel on Climate Change estimates that human activity will add 300 and 500 gigatons of carbon dioxide to the oceans by the end of the 21st century, so 310 is close to the best-case scenario. When I talked to Rothman, he said to keep in mind the uncertainty. “By looking at the geochemical record, it would appear we are going to put the system on a track toward some type of instability,” he said. “But how that works is highly speculative.”

People talk about climate change being settled science, he said, but that refers to the most basic parts. Scientists know approximately how much our emissions are likely to warm the planet — a factor called the climate sensitivity.

What we don’t know, he said, is how this linear relationship might break down. “The big unknown unknowns are the positive feedbacks,” he said. “The big risk is the system takes off on its own.”

Of course, nothing is certain. There’s still a remote chance that an asteroid will trigger the next mass extinction before we do it.

This column does not necessarily reflect the opinion of the editorial board or Bloomberg LP and its owners.

To contact the author of this story:
Faye Flam at fflam1@bloomberg.net

Huge Global Tsunami Followed Dinosaur-Killing Asteroid Impact

 

Thhttps://eos.org/articles/huge-global-tsunami-followed-dinosaur-killing-asteroid-impacte cataclysmic Chicxulub impact roughly 66 million years ago spawned a tsunami that produced wave heights of several meters in distant waters, new simulations suggest.

By  

The devastating tsunamis that struck the coastlines of Chile, Haiti, Indonesia, and Japan in recent decades produced waves tens of meters high, unimaginable to most people accustomed to gentle seas. But millions of years ago, a truly inconceivable set of waves—the tallest roughly 1,500 meters high—rammed through the Gulf of Mexico and spread throughout the ancient ocean, producing wave heights of several meters in distant waters, new simulations show.

The enormous waves were triggered by a large asteroid slamming into the shallow waters of the modern-day Yucatán Peninsula. That asteroid impact, which occurred about 66 million years ago and created the Chicxulub crater, contributed to the demise of the dinosaurs.

A Global Look

Molly Range, a paleoceanographer working at the University of Michigan when this research was conducted, and her colleagues have now modeled how the ensuing tsunami propagated in the Gulf of Mexico and beyond. “As far as we know, no one has done a global simulation of this impact,” said Range.

Range and her collaborators used two models: one simulating the initial impact of an asteroid 14 kilometers in diameter into shallow water and one modeling the ensuing propagation of displaced water throughout the ancient ocean. It was necessary to use the two models in tandem, explained Brian Arbic, a physical oceanographer at the University of Michigan who was involved in the study. “A typical ocean model just can’t handle an asteroid,” he noted.The first effect of the asteroid impact, the researchers found, would have been a roughly 1,500-meter-high tsunami wave. This wave represented the “initial blast of water away from the impact,” said Range.

A simulation is shown in the video below. Crustal material is shown in brown, sediments are shown in yellow, and the ocean is shown in blue.


A few minutes later, the models show that water began refilling the gaping crater formed by the impact. “You have a steep wall of water that rushes back in,” said Arbic. This rapid inflow likely triggered yet another set of waves. Although the strongest effects from the tsunami were felt in the Gulf of Mexico, the waves would have propagated globally, Range and her team found. Thanks to the seaway that existed between North America and South America at the time of the dinosaurs, the tsunami waves would have rushed freely into the Pacific Ocean.

Range and her colleagues calculated that the tsunami wave heights in the Pacific and Atlantic basins would have been as large as 14 meters. As these waves approached land and slowed down, they would have gotten even larger. But because the researchers’ models didn’t include the topography of the continents 66 million years ago, it wasn’t possible to calculate actual wave run-up heights, Arbic said.

The video below provides a look at how the waves propagated around the world as well as an estimate of their heights.

Displaced Sediments

The scientists also showed that the tsunami waves would have pushed water at the seafloor by more than 20 centimeters per second. Such strong water flows are sufficient to scour sediments from the bottom of the ocean, the researchers said. Scouring would have occurred in the South Pacific and the North Atlantic, the modeling revealed. Tantalizingly, in-progress research by the same team is showing that these very places are also where sediment coring experiments have found dislodged and displaced sediments.

These results were presented last week at AGU’s Fall Meeting 2018 in Washington, D. C.

The implications of this work are significant, said Timothy Bralower, an Earth scientist at Pennsylvania State University who was not involved in the research. “Geologists can now glean the sediments at sites far afield from the crater to detect the fingerprints of the tsunami.”

This modeling provides a glimpse into a cataclysmic part of Earth’s history that, thankfully, hasn’t been repeated. But more advanced simulations—incorporating, for example, higher spatial resolution or estimates of on-land topography so wave run-ups can be estimated—would improve our understanding of this tsunami, Arbic explained.But one thing is very clear: The Chicxulub tsunami was clearly a force to be reckoned with. As Arbic said, “It must have been one of the biggest tsunami ever.”

—Katherine Kornei (hobbies4kk@gmail.com@katherinekornei), Freelance Science Journalist

Scary picture of past global warming event painted in UW study

Harsh drought conditions in parts of the American West are pushing wild horses to the brink and forcing extreme measures to protect them. Federal land managers have begun emergency roundups in the deserts of western Utah and central Nevada. (AP Photo/Rick Bowmer)

Curtis Deutsch recently released a study in the journal Science that is the stuff of nightmares, or at least a major motion picture about a dystopian past.

The associate professor of oceanography at the University of Washington essentially ran a computer simulation of the end of the Permian geological period to try to determine why most of the Earth’s species were snuffed out 252 million years ago.

What’s extraordinary is what happened when Deutsch combined his model with data from fossils and information that scientists at Stanford have collected on animal species. They were able to conclude that greenhouse gases released from massive volcanoes warmed the Earth and depleted oxygen from the oceans, thus cooking or suffocating 96 percent of marine species and 70 percent of terrestrial species.

“Today, of course, we are the volcanoes,” Deutsch said. “We are accessing deep reservoirs of carbon stored in the Earth and we’re releasing that carbon dioxide in those fuels into the atmosphere. That’s ultimately what warms up the climate.”

RELATED: Gov. Inslee’s new climate plan nixes coal power
RELATED: Federal report lays out grim NW future with climate change
RELATED: UW prof says climate change is here and now

But, unlike the volcanoes of the Permian Period, humans can control how much carbon dioxide we release into the atmosphere. Deutsch says there’s more promise now that humans have the ability to move away from fossil fuels and harness the power of solar and wind.

“It’s true that we are well behind schedule and in many cases, including in this country, often lack the political willpower to do it, but scientifically and technologically, we can do it,” Deutsch said.

If humans end up dragging their feet and have to deal with another near-total extinction, there’s pretty good past evidence that shows the Earth will rebound and life will flourish once again. But, of course, paleontologists say it’ll take a few million years to build back the diversity of life that existed pre-mass extinction.

“Even knowing that diversity will return, I still think it’s better not to induce a large extinction event,” Deutsch said.

Fortunately for us, we’re smarter than marine life and we’re not living in a massive cloud of volcanic ash. So can’t we just invest in more air conditioning?

Deutsch says humans certainly have the ability to adapt to many of the results of global warming. For example, we’re able to plan for droughts, fight summer forest fires, and sit in front of air conditioners.

“The Permian Period extinction is a good example because there is a very clear signal in the data that shows us that when you push the climate to that level – 10 degrees of warming on the Celsius scale – you clearly are beyond the limits of adaptation. Temperatures get beyond what species would accommodate today and oxygen gets extremely low – beyond what most species can handle today.”

The problem with the extinction of the ocean is there is nothing we know of that will reverse the damage, according to Deutsch. It’s technologically infeasible to cool off the ocean and add more oxygen. The only way to avoid major disruption is to not allow the ocean to warm in the first place while also hoping that marine life is able to adapt. They must also contend with avoiding large fishing nets, which obviously weren’t around during the Permian Period.

Climate change will shrink US economy and kill thousands, government report warns

(CNN)new US government report delivers a dire warning about climate change and its devastating impacts, saying the economy could lose hundreds of billions of dollars — or, in the worst-case scenario, more than 10% of its GDP — by the end of the century.

The federally mandated study was supposed to come out in December but was released by the Trump administration on Friday, at a time when many Americans are on a long holiday weekend, distracted by family and shopping.
David Easterling, director of the Technical Support Unit at the NOAA National Centers for Environmental Information, emphasized that there was “no external interference in the report’s development.” He added that the climate change the Earth is experiencing is unlike any other.
“The global average temperature is much higher and is rising more rapidly than anything modern civilization has experienced, and this warming trend can only be explained by human activities,” Easterling said.
Coming from the US Global Change Research Program, a team of 13 federal agencies, theFourth National Climate Assessment was put together with the help of 1,000 people, including 300 leading scientists, roughly half from outside the government.
It’s the second of two volumes. The first, released in November 2017, concluded that there is “no convincing alternative explanation” for the changing climate other than “human activities, especially emissions of greenhouse gases.”
The report’s findings run counter to President Donald Trump’s consistent message that climate change is a hoax.
On Wednesday, Trump tweeted, “Whatever happened to Global Warming?” as some Americans faced the coldest Thanksgiving in over a century.
But the science explained in these and other federal government reports is clear: Climate change is not disproved by the extreme weather of one day or a week; it’s demonstrated by long-term trends. Humans are living with the warmest temperatures in modern history. Even if the best-case scenario were to happen and greenhouse gas emissions were to drop to nothing, the world is on track to warm 1.1 degrees Fahrenheit.
As of now, not a single G20 country is meeting climate targets, research shows.
Without significant reductions in greenhouse emissions, the annual average global temperature could increase 9 degrees Fahrenheit (5 Celsius) or more by the end of this century, compared with preindustrial temperatures, the report says.

The expense

The costs of climate change could reach hundreds of billions of dollars annually, according to the report. The Southeast alone will probably lose over a half a billion labor hours by 2100 due to extreme heat.
Farmers will face extremely tough times. The quality and quantity of their crops will decline across the country due to higher temperatures, drought and flooding. In parts of the Midwest, farms will be able to produce less than 75% of the corn they produce today, and the southern part of the region could lose more than 25% of its soybean yield.
Heat stress could cause average dairy production to fall between 0.60% and 1.35% over the next 12 years — having already cost the industry $1.2 billion from heat stress in 2010.
When it comes to shellfish there will be a $230 million loss by the end of the century due to ocean acidification, which is already killing off shellfish and corals. Red tides, or algae bloom that deplete oxygen in the water and can kill sea life — like those that triggered a state of emergency in Florida in August — will become more frequent.

Impacts on our health

Higher temperatures will also kill more people, the report says. The Midwest alone, which is predicted to have the largest increase in extreme temperature, will see an additional 2,000 premature deaths per year by 2090.
There will be more mosquito- and tickborne diseases like Zika, dengue and chikungunya. West Nile cases are expected to more than double by 2050 due to increasing temperatures.
Expect asthma and allergies to be worse due to climate change.
No one’s health is immune from climate change, the report concludes. People will be exposed to more foodborne and waterborne diseases. Particularly vulnerable to higher temperatures in the summer, children, the elderly, the poor and communities of color will be at a much greater risk for illness and death.

Heat and flooding

Wildfire seasons — already longer and more destructive than before — could burn up to six times more forest area annually by 2050 in parts of the United States. Burned areas in Southwestern California alone could double by 2050.
Dependable and safe water for the Hawaii, the Caribbean and others are threatened by these rising temperatures.
Along the US coasts, public infrastructure and $1 trillion in national wealth held in real estate are threatened by rising sea levels, flooding and storm surges.
Energy systems will be taxed, meaning more blackouts and power failures, and the potential loss in some sectors could reach hundreds of billions of dollars per year by the end of the century, the report said.
The number of days over 100 degrees Fahrenheit will multiply; Chicago, where these days are rare, could start to resemble Phoenix or Las Vegas, with up to two months worth of these scorching-hot days.
Sea levels have already gone up 7 to 8 inches since 1900. Almost half that rise has been since 1993, a rate of rise greater than during any century in the past 2,800 years. Some countries are already seeing land underwater.
By midcentury, it’s likely that the Arctic will lose all sea ice in late summer, and that could lead to more permafrost thaw, according to the report. As the permafrost thaws, more carbon dioxide and methane would be released, amplifying human-induced warming, “possibly significantly.”

What can be done

The report was created to inform policy-makers and makes no specific recommendations on how to remedy the problem. However, it suggests that if the United States immediately reduced its fossil fuel use and greenhouse gas emissions, it could save thousands of lives and generate billions of dollars in benefits for the country.
The Defense Department is trying to understand what risk climate change poses to security. But the Trump administration has signaled that the country will pull out of international initiatives like the Paris climate accord, aimed at lowering global temperatures, claiming that these treaties have been unfair for the US economy.
A report from the UN in October urged all governments to take “rapid, far-reaching and unprecedented changes in all aspects of society” to avoid disaster from climate change. That report predicted that the Earth will reach the crucial threshold of 1.5 degrees Celsius (2.7 degrees Fahrenheit) above pre-industrial levels by as early as 2030. It also suggested the world faces a risk of extreme drought, wildfires, floods and food shortages for hundreds of millions of people.

Time for action

Reactions to the new report have been strong across the scientific community.
“If we’re going to run this country like a business, it’s time to address climate as the threat multiplier we know it is before more lives are lost,” said Robert Bullard, an environmental scientist at Texas Southern University.
“In Houston, communities of color have endured back to back major weather events without the acknowledgment from Washington that climate change is the cause. We’ve known for years that it’s true and it’s important to our organizing and our local policy efforts that information like this is not only considered, but believed and acted upon.”
Scientists who have been raising the alarm about the negative consequences of climate change for years welcomed the findings.
Get CNN Health’s weekly newsletter

Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team.

“The findings in the Trump administration’s NCA report show how the health and daily lives of Americans are becoming more and more interrupted because of climate change,” said Beverly Wright, founding director of the Deep South Center for Environmental Justice and a professor at Dillard University. “We challenge the administration to finally begin using this information to rebuild and strengthen the communities in the direct path of the atrocities wrought by the fossil fuel industry and decades of poor policies that have neglected our concerns. The science is undeniable, let’s fix it.”