Antarctica floods cities

Antarctica floods cities

The melting ice in Antarctica and its disastrous consequences for the coastal cities of the world.

Antarctica

An international research team has warned of the danger of escalating warming, which in turn increases the rate of ice mass loss on the continent and the implications of this irreparable loss for coastal cities. cultural heritage sites around the world, from London to Mumbai, and New York to Shanghai, in a new study by the team on the stationary state of Antarctica.

Serious consequences.

The study was followed by researchers from the Potsdam Institute for Climate Impact Research in Germany and Columbia University in New York in the United States (New York's Colombia University).

In their study, published on September 23 in the journal Nature, a team of researchers shows how well the Antarctic ice sheet can resist warming.

The study followed the environmental impact over a period of approximately one million hours (approximately 114 years) from the date of the start of the detailed simulations of the climate models they developed.

They were able to determine the exact location at which the glacier would become unstable, as well as the associated warming levels. They found that when ice becomes unstable, it thaws and moves toward the ocean with disastrous long-term consequences.

For example, if the global average temperature level persists for a sufficiently long period of time at 4 degrees above pre-industrial levels, then the melting of Antarctica alone could raise the global sea level by more than 6 meters.

Direct correlation relationship.

Antarctica contains more than half of the Earth's freshwater, frozen in a vast ice cap about 5 kilometers thick.

In view of the warming of ocean waters and the atmosphere; Due to human greenhouse gas emissions, good Antarctic cover loses mass and eventually becomes unstable.

Thus, at a level of two degrees of warming, the melting of the ice and its accelerated flow in the ocean will ultimately lead to a height of 2.5 meters from the global sea level from Antarctica alone.

At 4 degrees of global warming, the sea level rise will be 6.5 meters, and at approximately 6 degrees the sea level will rise for an additional 12 meters, in the event of the continuous escalation of global warming degrees over a long period of time as is the case we are living in today.

Melting is slow but eternal.

Antarctica is considered a heritage foundation in Earth's nearly 34 million-year-old history, and simulations conducted by researchers have indicated that once melted, it will not return to its original state even. if the temperatures drop again.

In fact, temperatures are doomed to return to pre-industrial levels to allow a full recovery, which is an extremely unlikely scenario.

This means that what we lose from the southern continent is considered irrecoverable losses, due to intrinsic mechanisms of the behavior of the ice caps under global warming conditions, as the main driver of ice loss is warm water from there. the ocean, which causes higher melting under the ice shelves, which in turn leads to destabilizing the Earth's ice cap.

Once temperatures cross the 6-degree threshold above pre-industrial levels, giant icebergs slowly sink to lower altitudes as the air is warmer; This melts more ice, as it does in Greenland.

Our fate is in our hands. (Put oil on the fire).

The loss and melting of ice have accelerated considerably over the past decades in Antarctica. However, the authors did not explicitly address the issue of timescale in their work; Instead, they assessed the critical levels of warming, at which parts of the Antarctic ice sheet would become unstable.

This is where the researchers' original contribution lies in their study of determining the timescale of the cascading impacts of global warming.

Ultimately, it is our combustion of coal and oil that determines current and future greenhouse gas emissions, and so we can decide now whether we will be successful in stopping warming and protecting what lies behind it. rest. “Antarctica, and in a better sense to protect cities and cultural sites around the world, from Copacabana to Rio. From Janeiro to the Sydney Opera House to a dark fate in case we fail to stop this warming. So to give up on the Paris Agreement and not respect it means giving up cities like Hamburg, Tokyo, and New York.

The fungi and ecosystem

The fungi and ecosystem

The fate of plants in the face of climate change is linked to fungi.

Fungi

In a new series of studies, researchers have revealed that fungi will be one of the most important determinants of ecosystem response to future climate change, helping certain types of plants weather droughts and floods by expanding their roots with food and water. But these organisms are not immune to climate change, they say.

The vegetation and forest cover of the earth depend on what is underground, where about 90% of all plants have an invisible support system represented by fungal organisms that form thin threads that connect the roots of plants and they bring food and water.

In contrast, plants provide a constant supply of carbon to fungi, and this symbiotic relationship is scientifically known as mycorrhizae.

Symbiotic relationships.

At the American Environmental Association's annual conference in August, researchers revealed the results of a number of new scientific studies on the role of fungi in protecting forests from the risks of climate change.

These studies have shown, according to the journal Science, that fungi can play a role - more than just establishing symbiotic relationships with the organisms that live around them - by having the ability to determine how ecosystems respond to climate change, through to their ability to help. the plants survive. Life in hotter and drier conditions.

However, other studies have confirmed that climate change could in turn disrupt symbiotic relationships and possibly accelerate the disappearance of their host plants.

According to the researchers, these fungal relationships come in two forms: arbuscular mycorrhizae, common in tropical forests, and some temperate forests as well as in fields and grasslands, in which fungi invade root cells and extend thin filaments called stringy mushrooms.

Ectomycorrhizal form in which fungi settle on the outer surface of the roots and their filament networks lead to the growth of fungi on moist forest soils.

Both types take up phosphorus and other plant nutrients, capture nitrogen from decomposing organic matter and help store carbon in the soil.

Selective help.

To learn about the importance of the symbiotic relationship between fungi and plants in the face of the effects of climate change, Catherine Geering, an environmental specialist at Northern Arizona University, and her colleagues planted seedlings of two groups of plants, the 'one with mushrooms and the other without them. , under different irrigation systems.

The researchers found that the ectomycorrhizal-like symbiotic relationship played an important role in drought tolerance.

It has also been observed that the type of symbiotic relationship prevalent in a particular region is linked to different types of trees and that this relationship determines how plants and entire ecosystems respond to climate change. Which has led scientists to wonder if the fungi themselves help determine the type of forest that grows in this area.

The fungi are under threat.

But these symbiotic relationships, as scientists claim, are not immune to the impact of climate change, as many studies mention.

Christopher Fernandez, a soil ecologist at the University of Minnesota who simulated the effect of warming and drought processes on fungi below the ground in northern hemisphere forests, confirmed that as the atmosphere heats up and dries up, the diversity of fungi decreases.

If the same disturbance occurs with the evolution of climate change, the number of plant species that successfully establish symbiotic relationships with fungi could decrease, which could starve trees of nutrients.

“The picture has become clearer now. We cannot really ignore the symbiotic relationships between fungi and plants in response to climate change, ”Matthias Relig, an ecologist at the Free University of Berlin, told the conference.

Creatures feeding on viruses

Creatures feeding on viruses

A surprising discovery. Scientists discover, for the first time, creatures feeding on viruses.

virus as food

Viruses are found in astronomical numbers all over Earth, from the atmosphere to the depths of the oceans. Even its biomass is equivalent to about 25 billion people, but the strange thing, despite its abundance and richness in nutrients, is that there are no known living organisms that use it for food.

There is a growing body of evidence indicating that at least one group of organisms can feed on viruses, namely "protozoa and unicellular microorganisms".

Researchers in Frontiers in Microbiology published on September 24, 2020, the first convincing evidence that two groups of environmentally important marine primate organisms, namely Choanozoa and picozoa, two virus eaters, hunt their prey in a process. Ingestion.

A big surprise.

Dr. Ramunas Stepanauskas is the study leader and director of the Center for Single Cell Genomics at the Bigelow Laboratory for Ocean Sciences in Maine.

"Our data shows that many precursor cells contain the DNA genes of a wide variety of non-infectious viruses rather than bacteria, which clearly shows that they feed on viruses rather than bacteria. This was a big surprise," says Stepanauskas.

He adds that these results contradict prevailing views on the role of viruses and protozoa in marine food webs.

If the results of the study are correct, then a centuries-old doctrine will be turned upside down, instead of seeing viruses only as pathogens and seeing them play a role in nourishing and sustaining life.

"Viruses are rich in phosphorous and nitrogen, and they can be a good supplement to a diet rich in carbon," says Julia Brown, a microbiologist at Bigelow Laboratory and first author of the study, in the press release published on the science website Eurek Alert. . Also, "removing viruses from the water may reduce the number of viruses available to infect other organisms."

Sample collection and analysis.

Ramunas Stepanuskas and his colleagues started this research project more than ten years ago. Initially, they intended to study the pioneer marine preferences for prey, many of which feed on bacteria, but the results surprised them.

Surface seawater samples, including 1,698 pioneer individuals, were collected from the northwest Atlantic Ocean in the Gulf of Maine, the United States in 2009, and from the Mediterranean Sea off Catalonia, Spain, in 2016.

Stepanuskas and his colleagues then divided the cells and analyzed their contents. The team concluded that any genetic material that differs from the genetic material of protists may be a sign of something they ate.

After several rounds of analyzes, the researchers were surprised to find that there was not much bacterial material to be found. Instead, there were viruses of all shapes and sizes. Even viral genes were found in the cells of all the precursors of the funiculus and picosa groups.

It was a strange discovery, says Julia Brown. Although, since the 1990s, researchers have speculated that some early species could use viruses for food, this research did not receive much attention thereafter.

The issue of viral consumption.

However, finding viral genetic material in or around a cell does not guarantee that the virus was once food. For example, some viruses may have infected protists or just be stuck to the surface of cells.

However, Dr. Brown says it is "very unlikely that these viruses will be able to infect all the protists in which they are found."

"The new study alone cannot demonstrate the consuming relationship between protists and viruses," says Rika Anderson, a microbial ecologist at Carleton College in Minnesota who was not involved in the study, in a published report. in the New York Times.

But protists are found in a bewildering array of habitats, such as rotting tree stumps and animal guts, and they may have at least developed several strategies for foraging. “They eat everything, I wouldn't be surprised if they fed on viruses. "

Dr. Stepanauskas and Dr. Brown say that certain types of viruses are only found in certain groups of protists, suggesting that this was not just a coincidence.

Elephant deaths

Elephant deaths

Uncover the mystery of the massive elephant deaths in Botswana.

Elephant life

The Botswana Wildlife Service has revealed that hundreds of elephants that mysteriously died in the famous Okavango Delta were caused by poisoning by cyanobacteria.

This landlocked southern African country has the largest elephant population in the world, estimated at around 130,000 people.

Uncover the mystery and continue your search.

As noted in a report from the "Science Alert" website, since last March, more than 300 of these thick-skinned animals have died under mysterious circumstances, and their intact tusks have ruled out the possibility that the hunters killed them.

"The deaths were the result of poisonings from cyanobacteria growing in ponds or water pits," Maddy Robin, chief veterinarian of the Department of Wildlife and National Parks, told reporters on Monday.

The first report of unusual elephant deaths was identified on April 25 near the village of Seronga, and numbers started to rise the following month. Robin said the dead "stopped at the end of June 2020 as the pools dried up."

According to wildlife authorities, around 330 animals died and blood tests were consistent with the discovery that a type of neurotoxin-producing cyanobacteria was the cause. The tests were carried out in specialized laboratories in South Africa, Canada, Zimbabwe, and the United States.

Cyril Taullo, deputy director of Botswana's wildlife and national parks department, said officials ruled out anthrax infection and also ruled out human involvement in poaching. The government said it was continuing studies on the emergence of the bacteria.

The venom of male spiders

The venom of male spiders

The vast majority of spiders avoid confrontation, while the male Australian spider, considered one of the most dangerous spiders in the world, will attack and try to bite anything that threatens it, and clings to the victim, the stinging several times. to make sure he gets a full dose of his venom.

poisonous spider

This spider has been shown to be powerful at stings, is very aggressive, and has an incredible range of powerful fangs, which can penetrate shoes and nails, and using this destructive mechanism, the spider injects an appropriate dose of a potent toxin that affects the nervous system; the system, especially in primates, within minutes.

And recently, a group of Australian researchers studied the venom of the funnel-shaped spider and found that this type of spider had acquired the ability to kill humans by chance and that the fast-acting and highly toxic had probably evolved as a defense against predators. 

The results of the study were published in the Proceedings of the National Academy of Sciences (PNAS) on September 21 and included an article by two of the research participants published on The Conversation website.

Search for the female.

About 15% of all animals use poison for various reasons such as killing or immobilizing prey, defending themselves, or gaining an advantage over competitors during the breeding season, and as the animal matures and changes its activities, its poison changes. 

The Australian network's repressive spiders are one of a small group of spiders whose venom can kill humans, however, all of the previously reported deaths occurred before the introduction of antivenoms in 1981.

This toxin is fatal because it contains a type called “delta-hexatoxin”. This toxin can kill humans by attacking the nervous system and straining the nerves making them always "busy" by sending nerve signals.

Scientists have proven that when male repressive spiders are young, their venom is mainly strong for the insects that eat them, but once the male begins to look for a female, he must leave his safe burrow, and his venom, in it. the case becomes strong for vertebrates such as reptiles and mammals, including humans.

Very baffled.

Scientists have long wondered why these toxins are so deadly to humans when we and other primates have never fallen prey to web spiders throughout history.

Researchers attempted to solve this mystery using molecular analysis of the toxin. Although 35 species of repressive spiders are officially recognized, the Australian network identified 22 species of delta venom out of just 10 of them, and obtaining this data helped paint a much clearer picture. For the astounding story of poison.

Researchers examined the genomic sequences of all reticulocyte "delta hexatoxin" toxins and found that the female venom remains effective only against insects, but over time, the venom of adult males evolves to be potent against vertebrates.

Protection against predators.

Researchers believe this is all due to natural selection, as the genes responsible for this success are preserved and passed on to future generations. When repressive spiders evolved the web millions of years ago, their venoms targeted their natural prey from insects such as cockroaches and flies.

Leaving males in their burrows after sexually maturing and walking long distances to find a female has contributed to a change in the venom of adult male spiders as it has placed them in the path of vertebrate predators, which can include reptiles such as lizards, geckos. and mammals such as mice and birds.

The researchers intend to exploit this new knowledge after gaining a better understanding of the genetic sequences and evolution of “delta hexatoxin” toxins, and to study the effect of spider venom on the human body, which is crucial for improving antivenoms and designing new treatment strategies for bite victims.

Scientists also hope that studying the evolution of toxins will lead to new types of pesticides that are less harmful to non-target insects and have widespread effects.

Serial tornadoes

Serial tornadoes

hurricanes 

Tropical cyclones in the Atlantic could make 2020 the worst year.

When Tropical Storm Wilfred formed on September 18, the National Hurricane Center in the United States had exhausted its list of storm names for only the second time since naming began in 1950. Within hours, two more storms, now known as Alpha and Beta, formed.

The season is not over yet.

In an article on The Conversation from September 18, author Kimberly Wood, assistant professor of meteorology at Mississippi State University, explains the reasons for the high number and intensity of hurricanes this year.

“The most surprising thing is that we hit the 23rd tropical storm of the year, Beta, and that's over a month earlier than in 2005, the only other year recorded for so many named storms,” Kimberly said.

However, the 2020 Atlantic hurricane season is far from over. With the new storms, forecasters have moved from alphabetically listing people's names to letters of the Greek alphabet. And in the 2005 season, we saw 6 Greek lettering storms, ending with Zeta.

So why is the Atlantic Ocean so active this year? “Meteorologists like me have been tracking some important differences, including the many tropical storms that have formed near the American coast,” Kimberly says.

What is the reason for a large number of tropical cyclones?

When there is turbulence - a large mass of convective clouds or thunderstorms - over the Atlantic Ocean, certain weather conditions will help it develop into a tropical cyclone.

Hot water and lots of humidity help the turbulence to gain strength. The instability allows air packages to rise and continue to create thunderstorms.

This year, sea surface temperatures were above average across much of the Atlantic and wind shear was below average, meaning it was more suitable than usual for training tropical cyclones.

Maybe La Niña is linked to it as well. The La Niña phenomenon is the opposite of El Niño - it occurs when sea surface temperatures in the eastern and central Pacific Ocean are below average.

This cooling is affecting weather conditions in the United States and elsewhere, including weakening wind shear in the Atlantic Basin.

And at the beginning of September, NOAA decided that we are going into a “La Niña” climate model.

This pattern has been building for weeks, so these common conditions could have contributed to the Atlantic Ocean's adequacy for tropical cyclones this year.

A turn off the American coast.

Four hurricanes have hit the US coast this year - Hanna, Isaias, Laura, and Sally - which is more than usual at this point in the hurricane season. But we also saw several short-lived tropical storms that had less impact.

And when a tropical cyclone develops turbulence over Africa, it has a lot over the ocean with room to organize and gain strength. But this year, many storms have formed in the far north, closer to the American coast.

Most of them came from disturbances that weren't very promising until they moved over the Gulf Stream, a large ocean current that carries warm water from the Gulf of Mexico to the east coast to the North Atlantic.

Tropical cyclones are expected to form temperatures higher than sea surface temperatures exceeding 80 degrees Fahrenheit (26.6 degrees Celsius), and warm waters along the Gulf Stream can help disrupt tropical cyclones.

And since these tropical storms were already far enough north, they didn't have much time to build up.

Meteorologists have yet to investigate why so many storms form this way this season, but it's likely due to warmer-than-usual Atlantic waters and the location of the Gulf Stream.

the origin of water on earth

 The origin of water on earth

In a recent study ... scientists found the origin of water on Earth.

origin of water

Was the earthling dry or wet? A question that baffled scientists for a long time, and because our planet was relatively close to the scorching heat of the sun 4.5 billion years ago, the belief has remained that the Earth was born dry and that it later obtained its water, which constitutes 70% of its area, from the collision of asteroids and comets from the cold and icy depths of the outer solar system.

However, in a new study published in the journal Science on August 28, 2020. A French research team reported that they identified space rocks as the source of this water and that our planet has been humid since its formation.

Hydrogen-laden rocks.

Researchers from the Center for Petrographic and Geochemical Research at the University of Lorraine (CRPG, CNRS) analyzed 13 different enstatite chondrites, a class known to look like space rocks that merged to form the Earth more than 4 years ago, 5 billion years.

The researchers found that this type of rock contains a lot of hydrogen, indicating that our planet was not born dry, as the team's calculations indicate that the rocks that formed the Earth were home to at least 3 times the amount of water. held by the current oceans of the planet.

"Our discovery shows that the building blocks of the Earth may have contributed significantly to the Earth's water," said study author Laureate Bayani. "Materials containing hydrogen were present in the inner solar system when the rocky planet was formed, even though the temperatures were too high for water to condense."

Ann Bessler, a researcher at NASA's Johnson Space Center in Houston, commented in a companion article in the same issue of Science, saying, "Maybe Earth's water was just coming from nebulous matter." Where the planet is from. "

Prevailing theory.

Bayani says the results contradict the prevailing theory that water was originally brought to dry Earth by far-reaching comets or asteroids.

And that, according to the first models of the appearance of the solar system, the large disks of gas and dust revolving around the sun and forming the inner planets were very hot, which would explain the arid conditions on Mercury, Venus and Mars; But our blue planet, with its vast oceans and wet faces, is not.

Scientists, therefore, assumed that the water came after the formation of the earth and that the main source - according to the scientists - was meteorites called carbon chondrites rich in minerals from the water. The problem, however, was that its chemical makeup did not closely match that of the rocks on our planet.

It is the opposite of a group of meteorites, "enstatite chondrite" (EC), which has a much closer chemical match to rocks on Earth and contains similar isotopes of oxygen, titanium, and calcium, indicating that they were the building blocks of the Earth and other inner planets.

Amazing results.

To test if the chondritic enstatite rocks are as dry as thought due to their formation near the sun or the source of rich water on Earth, Bianni and his colleagues used a technique called "mass spectrometry." to measure the hydrogen content of anastatic chondrite.

The team found that rocks contain enough hydrogen to provide Earth with three times the mass of water in its oceans, and possibly much more.

They also found that the isotopic composition of enstatite chondritic hydrogen is similar to that found in water stored in the Earth's mantle.

The isotopic composition of oceanic waters corresponds to a mixture containing 95% of the water from anastatic chondrites and only 5% of water is carried by comets or asteroids rich in water.

Bayani says the research also does not rule out that there are other sources of water on Earth such as comets. But he points out that enstatite chondrites made a significant contribution to the Earth's water balance at the time of its formation.

volcanic ash

A recent study on volcanic ash

Volcanic ash affects the atmosphere and may block sunlight

volcano

When volcanoes erupt, these geological monsters produce massive clouds of ash and dust - plumes that can blacken the skies and block air traffic, reaching heights nearly 25 miles (over 32 km) above. from the surface of the Earth.

And a new study from the University of Colorado at Boulder indicates that this volcanic ash could have a bigger impact on the planet's climate than scientists previously thought.

The new study, published in Nature Communications on September 10/2020, examines the 2014 eruption of the Mount Kelut (or Kelud) volcano on the Indonesian island of Java in 2014.

Using real-life observations of the event and advanced computer simulations, the team found that the volcanic ash appears to have peeled off and remained in the air for months or more after a large eruption.

"What we found in this volcanic eruption is that volcanic ash can last for a long time," says Yunqian Chu, lead author of the new study and a research scientist at the Laboratory of Atmospheric and Space Physics (LASP) at the University of Colorado.

The discovery began with a note of accident, as members of the research team were flying a drone near the site of the Mount Kilut eruption - an event that covered large parts of Java with ash and prompted people to leave their homes. "They saw some large, ash-like particles floating in the atmosphere a month after the explosion," Chu says.

She explained that scientists have known for a long time that volcanic eruptions can negatively affect the planet's climate, as they explode with huge quantities of sulfur-rich particles in the Earth's atmosphere and can prevent sunlight from reaching the Earth.

However, the researchers did not believe that the ash could play such a large role, as scientists speculated that these pieces of rock debris were so heavy that most of them probably fell from the volcanic clouds soon after. an eruption.

Drawing on aerial and satellite observations of the disaster, the team found that the volcano's plume appears to be filled with tiny particles of light ash - tiny particles that can float in the air for long periods of time, like dandelion fluff.

“The researchers speculated that the ash looked like obsidian ... but what we found is that this float has a density that is very similar to pumice,” Chu said. Pumice is a light, porous glassy volcanic rock that fills with holes created by gas bubbles trapped as it hardens.

The disappearance of the particles.

Ton, a professor in the Atmospheric and Space Physics Laboratory and Department of Atmospheric and Oceanic Sciences at the same university, explained that erupting volcanoes eject a large amount of sulfur dioxide.

The researchers previously speculated that these molecules interact with other particles in the air and turn into sulfuric acid, in a series of chemical reactions that can theoretically take weeks.

But the factual observations indicate that it is happening much faster than that. “There was a mystery as to why these reactions happened so quickly,” Ton says.

Ton and his colleagues believe they have found the answer: these particles of sulfur dioxide seem to stick to particles of ash floating in the air. In the process, it can undergo chemical reactions on the surface of the ash itself, which could cause about 43% of the sulfur dioxide to be removed from the air.

In other words, ash can accelerate the conversion of volcanic gases in the atmosphere. So what is the impact of these ash clouds on the climate? It's unclear. Long-lived particles in the atmosphere could, in theory, darken the planet and even help cool it after it erupts.

Float ash can also explode en route between sites such as mount Kiloot and the poles of the planet. There, it could set off chemical reactions that would destroy the Earth's most important ozone layer.

But researchers say one thing is clear: When volcanoes erupt, it is time to pay more attention to all this ash and its true impact on Earth's climate.