Friday, May 15, 2020

There's a Surprising Connection Between Dangerous Algal Blooms And The Himalayas

A loss of snow and ice on Earth's highest mountain peaks could be driving dangerous changes in the food chains of distant coastal water, according to new research.
© Provided by ScienceAlert shrinkingsno

Like a gardener turning over soil, cold winter winds blowing down from the Himalayan mountains are known to fertilize the Arabian sea by chilling the surface and causing the dense waters to sink, only to be replaced with fresh currents rich in nutrients.

Due to climate change, however, winter monsoons are rapidly becoming warmer and moister, leaving marine habitats with less oxygen and nutrients, and allowing microbes that thrive in an oxygen-depleted wasteland to bloom instead.

Recently, it's gotten so bad, the thick green swirls of algal blooms can actually be seen from space.

What you're looking at is Noctiluca scintillans - also known as sea sparkle for its bio-luminescent effects. This is a millimetre-long marine dinoflagellate that can survive and thrive without oxygen or sunlight. Before the turn of the century, however, its presence along the coasts of Somalia, Yemen, and Oman was practically unheard of.

Today, it regularly causes massive blooms with widespread effects on ecosystems and industries. Something has clearly changed quite rapidly, far more than seems natural, and researchers now think the rise of Noctiluca in the Arabian Sea has to do with the climate crisis.

"This is probably one of the most dramatic changes that we have seen that's related to climate change," says Joaquim I. Goes from Columbia University, who has been studying the rapid rise of this organism for more than 18 years.

"We are seeing Noctiluca in Southeast Asia, off the coasts of Thailand and Vietnam, and as far south as the Seychelles, and everywhere it blooms it is becoming a problem. It also harms water quality and causes a lot of fish mortality."

Using field data and NASA satellite imagery, scientists have now connected the rise of these algae blooms to melting glaciers and a weakened winter monsoon.

Since 1980, the authors found mixing on the surface of the Arabian sea had decreased alongside warming winter monsoon winds that were less powerful but more humid.

"Collectively, these changes have resulted in an increase in net-heat flux from the atmosphere into [Arabian Sea] surface waters that indicates an increase in the upper [Arabian Sea] ocean heat content since 2000," the authors write.

For the tiny organisms that help make up a solid base to the ecosystem's food web, such as diatoms, this implies a problem. But for the less appetizing Noctiluca, the authors say this is a "tremendous competitive advantage".

In the lab, researchers have previously shown Noctiluca cells photosynthesize more efficiently under conditions with low oxygen or when nutrients are depleted.

Diatoms, on the other hand, need nutrient-rich conditions on the surface of the ocean where sunlight is ample. And if monsoon winds aren't stirring up that habitat on a yearly basis, there's a serious problem.

This means Noctiluca is a fierce competitor to many of the essential organisms holding up our marine environments. When winter monsoons are lacklustre and less nutrient mixing occurs on the surface of the sea or ocean, diatoms struggle to survive.

On the other hand, Noctiluca can survive in harsher environments, sometimes even by eating other microorganisms. Additionally, ammonia easily builds up in their own bodies, making the algae a particularly nasty, even poisonous morsel.

In today's rapidly changing Arabian Sea, this deadly and adaptive behaviour appears to be "short-circuiting the food chain", leaving fish poisoned, diatoms outcompeted and jellyfish numerous.

"Most studies related to climate change and ocean biology are focused on the polar and temperate waters, and changes in the tropics are going largely unnoticed," says Goes.

In light of their results, the authors suggest Noctiluca outbreaks are triggered each summer by the intrusion of hypoxic waters into the upper layers of the Arabian sea.

Here, the algae can rapidly photosynthesize, while other organisms are left "severely nutrient limited by a weaker convective mixing" due to a loss of snow cover in the Himalayas.

In countries like Somalia and Yemen, the authors fear this annual bloom, which is only getting bigger with the years, could harm local fisheries, leading to further unrest, poverty and deprivation as climate change strengthens its grip and the Himalayas continue to melt at an unprecedented rate.

"The inability of large zooplankton, except salps and jellyfish to feed on Noctiluca, is indicative of the capacity of Noctiluca blooms to short-circuit the trophic food chain," the authors write.

"Thus, their annual reoccurrence and growing dominance in winter each year will require a revision of our fundamental understanding of the [Arabian Sea] food web."

The study was published in Nature Scientific Reports.

Scientists Find The First Animal That Doesn't Need Oxygen to Survive


Some truths about the Universe and our experience in it seem immutable.

 The sky is up. THE SKY IS NOT UP OR DOWN IT IS OUT THERE 
 Gravity sucks. 
Nothing can travel faster than light. NOT TRUE CERN/LHC CREATED FASTER THAN LIGHT NEUTRINO'S
Multicellular life needs oxygen to live. Except we might need to rethink that last one.© Stephen Douglas Atkinson

Earlier this year, scientists discovered that a jellyfish-like parasite doesn't have a mitochondrial genome - the first multicellular organism known to have this absence. That means it doesn't breathe; in fact, it lives its life completely free of oxygen dependency.


This discovery isn't just changing our understanding of how life can work here on Earth - it could also have implications for the search for extraterrestrial life.

Life started to develop the ability to metabolise oxygen - that is, respirate - sometime over 1.45 billion years ago. A larger archaeon engulfed a smaller bacterium, and somehow the bacterium's new home was beneficial to both parties, and the two stayed together.

That symbiotic relationship resulted in the two organisms evolving together, and eventually those bacteria ensconced within became organelles called mitochondria. Every cell in your body except red blood cells has large numbers of mitochondria, and these are essential for the respiration process.

They break down oxygen to produce a molecule called adenosine triphosphate, which multicellular organisms use to power cellular processes.

We know there are adaptations that allow some organisms to thrive in low-oxygen, or hypoxic, conditions. Some single-celled organisms have evolved mitochondria-related organelles for anaerobic metabolism; but the possibility of exclusively anaerobic multicellular organisms has been the subject of some scientific debate.

That is, until a team of researchers led by Dayana Yahalomi of Tel Aviv University in Israel decided to take another look at a common salmon parasite called Henneguya salminicola.




h salminicola
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h salminicola(Stephen Douglas Atkinson)

It's a cnidarian, belonging to the same phylum as corals, jellyfish and anemones. Although the cysts it creates in the fish's flesh are unsightly, the parasites are not harmful, and will live with the salmon for its entire life cycle.

Tucked away inside its host, the tiny cnidarian can survive quite hypoxic conditions. But exactly how it does so is difficult to know without looking at the creature's DNA - so that's what the researchers did.

They used deep sequencing and fluorescence microscopy to conduct a close study of H. salminicola, and found that it has lost its mitochondrial genome. In addition, it's also lost the capacity for aerobic respiration, and almost all of the nuclear genes involved in transcribing and replicating mitochondria.

Like the single-celled organisms, it had evolved mitochondria-related organelles, but these are unusual too - they have folds in the inner membrane not usually seen.

The same sequencing and microscopic methods in a closely related cnidarian fish parasite, Myxobolus squamalis, was used as a control, and clearly showed a mitochondrial genome.

These results show that here, at last, is a multicellular organism that doesn't need oxygen to survive.

Exactly how it survives is still something of a mystery. It could be leeching adenosine triphosphate from its host, but that's yet to be determined.

But the loss is pretty consistent with an overall trend in these creatures - one of genetic simplification. Over many, many years, they have basically devolved from a free-living jellyfish ancestor into the much more simple parasite we see today.


h salminicola monochrome sm
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h salminicola monochrome sm(Stephen Douglas Atkinson)

They've lost most of the original jellyfish genome, but retaining - oddly - a complex structure resembling jellyfish stinging cells. They don't use these to sting, but to cling to their hosts: an evolutionary adaptation from the free-living jellyfish's needs to the parasite's. You can see them in the image above - they're the things that look like eyes.

The discovery could help fisheries adapt their strategies for dealing with the parasite; although it's harmless to humans, no one wants to buy salmon riddled with tiny weird jellyfish.

But it's also a heck of a discovery for helping us to understand how life works.

"Our discovery confirms that adaptation to an anaerobic environment is not unique to single-celled eukaryotes, but has also evolved in a multicellular, parasitic animal," the researchers wrote in their paper, published in February 2020.

"Hence, H. salminicola provides an opportunity for understanding the evolutionary transition from an aerobic to an exclusive anaerobic metabolism."

The research has been published in PNAS.

A version of this article was first published in February 2020.

Even If Climate Change Wasn't Happening, Phasing Out Coal Is A 'No-Regret' Solutio

The benefits of phasing out coal far outweigh the real-world costs, scientists say, and that's the case even when climate change is left out of the equation entirely.
© John W Banagan/Stone/Getty Images

Of all the fossil fuels in the world, coal is the biggest source of carbon dioxide, and its impacts on air pollution and public health are profound.

Since the beginnings of the Industrial Revolution, large-scale coal burning has cost lives, yet we've been struggling to kick it. Our global reliance on coal runs deep, so deep that even though we know it's bad for us, we continue to burn it at unprecedented levels.

Now, new computer simulations on the regional effects of phasing out coal suggest that continuing on this trajectory is a big mistake, with negative impacts not only on the environment and human health, but also the economy.

"We're well into the 21st century now and still heavily rely on burning coal, making it one of the biggest threats to our climate, our health and the environment," says Sebastian Rauner who researches climate impacts at the Potsdam Institute for Climate Impact Research (PIK).

"That's why we decided to comprehensively test the case for a global coal exit: Does it add up, economically speaking? The short answer is: Yes, by far."

The simulation the team has created incorporates information on the full extent of a 'coal exit' scenario, accounting for air pollution as well as the impact on the energy sector as a whole.

Using this thorough modelling, researchers have now examined the direct and indirect effects of three different scenarios: one, where we meet our current emission-cutting pledges by 2030; another, where we limit global temperature rise by the end of the century to 2 °C through carbon pricing; and a third, where we almost completely phase out coal by 2050.

This, of course, would be a substantial transformation of the energy system as we know it, but it may well be worth it.

Monetising the environmental and human health costs for the first time - including how much it would cost to re-wild areas and invest in transforming our energy systems - the authors have come to a stunning 'no-regret' decision.

Cutting off our reliance on coal will be hugely beneficial for most regions in the world, even when you don't take into account the global benefits of slowing down climate change.

In the simulations, the effects on air pollution in the coal exit scenario are at almost similar levels to the 2 °C scenario, improving global public health exponentially, especially in Asia.

In fact, in almost all regions of the world, the direct policy cost of exiting coal was nothing compared to the human health and environmental benefits that will be reaped come 2050.

Only sub-Saharan Africa, Latin America and Japan faced higher costs than benefits, and the authors think that might be because air pollution isn't as much of a problem in these parts.

Under the scenario where nations put a price on carbon to limit a temperature rise to 2 °C, a somewhat scattered picture emerges. Asia benefits from improved air quality, while Europe, Japan, and the US save on policy costs. The rest of the world, however, falls short of reaping the same direct societal benefits.

But keep in mind, that's only for regional effects. The minute we zoom out and consider climate change on a global level, everyone appears to win.

"We find that, based on all countries' current climate pledges under the Paris Agreement, humanity is so far not on track to keep global warming below 2 degrees," says Rauner.

"Yet, if all countries would introduce coal exit policies, this would reduce the gap to fulfilling the goal by 50 percent worldwide. For coal-heavy economies like China and India, quitting coal would even close the gap by 80-90 percent until 2030."

The authors argue exiting coal is a particularly valuable strategy going forward, because it reduces carbon dioxide emissions at a relatively low cost while also reaping huge local benefits, such as a reduction in air pollution.

Still, even then, coal is just a start, or, as the authors say, a "crucial early entry point." Phasing out our use of it is a way to buy us some time so we can create further climate policies that turn us away from other fossil fuels and towards more renewable forms of energy. Exiting coal is not a solution to the whole problem.

"[A] holistic response to the climate and environmental crisis will eventually have to achieve almost full-scale decarbonization of power supply," the authors conclude, "and thus also entail a deep reduction of not only coal but also oil and gas and address non-electric energy demands in transportation, buildings and industry sectors as well as resource efficiency."

The study was published in Nature Climate Change.
Wildlife habitat destruction and deforestation will cause more deadly pandemics like coronavirus, scientists warn
© Provided by CNBC The orangutans in Indonesia have been known to be on the verge of extinction as a result of deforestation and poaching.
As climate change contributes to a surge in disease outbreaks across the world, scientists warn that current rates of environmental degradation and biodiversity loss will lead to more deadly pandemics like the coronavirus.

The total number of disease outbreaks has more than tripled each decade since the 1980s. More than two thirds of the diseases originated in animals and most of those were directly transmitted from wildlife to people.

Habitat destruction like deforestation and agricultural development on wildland are increasingly forcing disease-carrying wild animals closer to humans, allowing new strains of infectious diseases to thrive.

"When you cut down trees and remove the forest, you eliminate the natural environment of some species. But those species don't just disappear," said Roger Frutos, an infectious diseases researcher at the University of Montpellier in France.

"We instead create a patchwork, a mosaic of their environment that's closer to ours, with houses that attract insects or sheds where bats can rest and find shelter," he said.

Scientists say the coronavirus pandemic is the most recent instance of how human degradation of wildlife habitats is linked to the spread of infectious diseases. Research has found that Covid-19 likely originated in a horseshoe bat and was then transmitted through another animal.

Bats are less likely to transmit viruses to humans when they are in wild habitats, but land conversion has increased their exposure to humans and upped the chances of virus transmission. There's now a higher density of bat-borne viruses and pathogens near human dwellings worldwide, according to Frutos.

Some researchers estimate that more than 3,000 strains of coronavirus could already exist in bats and could be transmitted to humans.

"When you're building human homes right up on forest edges, you're destroying wildlife habitats and squeezing animal habitats into smaller areas," leading to a more likely transmission of disease to humans, according to Tierra Smiley Evans, an epidemiologist at the One Health Institute at the University of California.
© Provided by CNBC Aerial view of deforestation in Nascentes da Serra do Cachimbo Biological Reserve in Altamira, Para state, Brazil, in the Amazon basin, on August 28, 2019.

Only about 15% of the world's forests, which are key to maintaining biodiversity, remain intact after degradation from logging, fires and agricultural expansion, according to the World Resources Institute. Millions of animal and plant species currently face extinction because of habitat destruction.

South America is a prime area of concern over infectious disease spread due to rapid deforestation of the Amazon rainforest from logging and mining, which researchers say will aggravate wildfires and Covid-19 spread in the region.

"Preserving habitats for wildlife and preserving our world is a human health issue, not just a wildlife or environmental issue," said Smiley, who studies deforestation and virus spread in Myanmar.

Scott Weaver, director of the Institute for Human Infections and Immunity at the University of Texas Medical Branch in Galveston, said deforestation will increase the risk of many mosquito-borne viruses in areas like the tropics, Latin America and Southeast Asia.

Poorer countries will suffer the most from diseases made worse by climate change, since warmer temperatures will increase the spread of viruses like dengue fever in places where people can't afford air conditioning and general protections against disease exposure, Weaver said.

For instance, the West Nile virus, a mosquito-borne disease, replicates a lot faster in hotter climates. Researchers believe that global warming is allowing the virus to spread more efficiently in wild birds, who then infect people.

"We're in this predicament with the coronavirus because we've under invested in public health across the world and we haven't taken scientific information into account in political decisions," Weaver said.

There are more than 3.8 million confirmed Covid-19 cases across the world and at least 269,881 people have died from the disease, according to data by Johns Hopkins University.

"Hopefully the awakening from this Covid-19 pandemic will get people paying more attention to scientists telling us about these risks that could spill over into vector-borne diseases," Weaver added. 
Stone Tools Show How Humans Survived a Supervolcano Eruption 74,000 Years Ago


Of all the volcanic eruptions to shake our planet in the last 2 million years, the Toba super-eruption in India was one of the most colossal. But it may not have been the global catastrophe we once thought it was.

The massive eruption happened roughly 74,000 years ago, spewing roughly 1,000 times as much rock as the 1980 eruption of Mt St Helens. For a while there, some thought the fall-out was so extreme, it triggered a decade-long "volcanic winter" and a millenia-long glacial period.

This so-called Toba catastrophe theory left the global human population with just a few thousand survivors. Except, that's probably an exaggeration.

In recent times, archaeological evidence in Asia and Africa has suggested that while the eruption was indeed tremendous, the consequences were not so apocalyptic after all, and it certainly didn't leave humans on the brink of extinction.

Now, an ancient and "unchanging" stone tool industry, uncovered at Dhaba in northern India, suggests instead that humans have been present in the Middle Son Valley for roughly 80,000 years, both before and after the Toba eruption.

"Populations at Dhaba were using stone tools that were similar to the toolkits being used by Homo sapiens in Africa at the same time," explains archaeologist Chris Clarkson from the University of Queensland.

Screen Shot 2020 02 25 at 12.53.13 pm

"The fact that these toolkits did not disappear at the time of the Toba super-eruption or change dramatically soon after indicates that human populations survived the so-called catastrophe and continued to create tools to modify their environments."

The Toba catastrophe theory centres around a correlation, and a controversial one at that. At about the same time as the Toba volcano was blowing, all those millennia ago, our species was also going through a genetic bottleneck; the eruption seemed like a plausible cause for this drop in diversity.

But over the years, the catastrophe theory has not held up to scientific scrutiny. In 2007, evidence of stone tools in southern India suggested the Toba eruption did not lead to extreme cooling, nor trigger a glacial period.

Some have pushed back and argued that these tools were not made by Homo sapiens, but whoever they were sculpted by appeared to survive this natural disaster.

In 2018, further fossil evidence from South Africa added even more support to the idea that global human populations not only made it through the Toba eruption, they might have even thrived in its wake.

Geneticists agree that 70,000 years ago, there was an unmistakable drop in human genetic diversity, but that shift may not have been the result of a super-eruption. Some think it might simply be a founder effect.

a group of clouds on a rocky beach

As humans spread across Eurasia and branched off into smaller and smaller groups, their genetic diversity may have also begun to dwindle. And that's probably why genetic diversity in Africa is so much higher than elsewhere.

The thousands of newly described stone tools found in Dhaba have helped fill in some of that timeline. The results suggest humans migrated out of Africa and expanded across Eurasia much earlier than expected, surviving a brutal natural disaster in the meantime.

The study authors say most of the tools found in Dhaba resemble African and Arabian techniques from the Stone Age, and some even look like early human artefacts from Australia.

The team claims these are unmistakably human-made, connecting the dots of early migration from Africa to southeast Asia and then on to the great south land.

"Modern human dispersal out of Africa, and more importantly east of Arabia, must therefore have taken place before [65,000 years ago]," the authors write.


"The Dhaba locality serves as an important bridge linking regions with similar archaeology to the east and west."

But without human fossils to back up the find, there are some who remain unconvinced these tools were made by Homo sapiens. This particular stone tool technique was also employed by Neanderthals; anthropologist Stanley Ambrose has told Science Magazine he thinks it's impossible to tell which species actually made the tools.

If the dates are right, however, it doesn't really matter who sculpted the tools. Whether created by Homo sapiens or other ancient hominins, whatever populations did reside in Dhaba were not nearly wiped out by the Toba eruption.

Although, something else probably ended them. The people who lived here have not contributed much to the modern gene pool, which means they probably faced other challenges to their ongoing survival.

"The archaeological record demonstrates that although humans sometimes show a remarkable level of resilience to challenges, it is also clear that people did not necessarily always prosper over the long term," says anthropologist Michael Petraglia of the Max Planck Institute.

It just wasn't the volcano that got them.

The study was published in Nature Communications.

Climate change, pollution impacts hurricane formation in the Atlantic, NOAA study says

By Alex Harris, Miami Herald MAY 15, 2020


MIAMI — In the last 40 years, the East Coast, including Florida, has been hit by dozens of hurricanes.
© Joe Burbank/Orlando Sentinel/TNS A Lowes customer loads plywood in his truck at the hardware store in Altamonte Springs, Fla., Friday, Aug. 30, 2019, as central Florida residents prepare for a possible strike by Hurricane Dorian.

New NOAA research suggests human pollution may have increased the likelihood of those Atlantic basin storms, but not in the way you might expect.


A decrease in aerosol pollution over the last 40 years, along with a couple of volcanic eruptions, played the largest role in the increase in hurricanes, said lead author Hiroyuki Murakami, a climate researcher at NOAA’s Geophysical Fluid Dynamics Laboratory.

Climate change also played a role, although it was “outperformed” in the Atlantic basin specifically by aerosols and volcanoes, Murakami said.

This is the latest in a line of research that seeks to disentangle the complex relationship between climate change and natural variability in hurricane formation.

“At this point, there’s no event that is 100% naturally driven and there’s no event that’s 100% climate change. It’s all shades of gray,” said Phil Klotzbach, a research scientist at Colorado State University not involved with the study.

The study by the National Oceanic and Atmospheric Administration examined every storm from 1980 to 2018 and found that the buildup of greenhouse gases in the atmosphere, along with changes in other human pollution, has changed how often storms form in certain locations. Some spots, like the Atlantic basin, saw a “substantial increase” in storms, but other spots, like the southern Indian Ocean, saw far fewer.

Volcanic eruptions from El Chichón in Mexico in 1982 and Mount Pinatubo in the Philippines in 1991 also cooled the atmosphere nearby and shifted storm activity. But NOAA scientists said the impacts of those eruptions dissolved by 2000 and didn’t impact the next 18 years of activity.

For the Atlantic basin, the birthplace of the storms that threaten Florida, Murakami’s team found that lower levels of aerosol pollution played a large role in the frequency of storms. Aerosols are small particles in the air and can be naturally occurring, like dust or sand, or human-caused like the thick smoke caused by burning diesel fuel. Clouds of air pollution shade ocean waters and keep temperatures down, making it harder for hurricanes to strengthen.

“When you have more aerosols and dust, especially in the Caribbean, you tend to have a quiet overall hurricane season,” Klotzbach said.

With fewer particles clogging up the air, the sun-warmed ocean was the perfect conduit for strong storms, especially when paired with increasing greenhouse gas pollution, which traps heat in the atmosphere.

But although the study found that climate change played a role in shifting storms toward and away from certain spots on the planet, it didn’t affect the overall number of storms that formed. However, the research showed that as the planet continues to heat up it could eventually lead to fewer hurricanes overall. But the ones that do form are more likely to be powerful Category 3, 4 and 5 hurricanes.

“In the future, we predict a decrease in tropical storms,” Murakami said. Yet “we still predict increasingly strong tropical cyclones.”

Climate change’s role in forming storms remains complicated and not well understood. Scientists are careful not to make absolute statements like “climate change caused X hurricane,” because that’s not what the research shows.

Attribution science, as the field is known, is about discovering if climate change makes something more or less common. Murakami said that’s simpler to do over a long period of time, like the 40 years analyzed in the study.

“Statistically speaking we can find some significant trends,” he said. “But when you look at a specific tropical cyclone it’s really difficult to figure out how climate change affected it.”

Some connections, like hotter oceans fueling more powerful storms, are simple enough. As sea levels rise, hurricanes have more water to shove ashore, making storm surge higher and deadlier.

But as the air above the oceans warms, it actually makes the atmosphere more stable and complicates storm formation. That’s why the NOAA study found that toward the end of the century the average annual number of tropical cyclones around the world could drop from 86 to 69.

And then there’s the question of whether climate change will impact the number of El Niños and La Niñas, weather systems that affect how and where hurricanes form around the globe.

“That’s a big question too. There’s no consensus there,” Klotzbach said. “There’s so many questions that need to be answered.”

Hurricane season starts June 1, although a disturbance passing through the Florida Straits could strengthen into the first named storm of the season — Arthur — over the weekend.

———

©2020 Miami Herald
Photos taken 1 year apart show potentially troubling sign in volcano


The Halema‘uma‘u crater on Kilauea, located in Hawaii, has been relatively quiet over the last year after a frenzy of activity in 2018, which all began with an explosive eruption of ash 30,000 feet into the air during May. But, since at least 2019, there has been a change that scientists believe could pose a potential danger to the Big Island. Water has started to collect in the caldera to form a lake.

A caldera is a large crater left behind in a volcano after an eruption. From 2010 until 2018, a lava lake had filled the caldera rather than water. That changed in May 2018 when the eruption caused the lava lake to drain, collapsing the caldera floor and causing a hole nearly as deep as the 1,776-foot One World Trade Center. The eruption also created a 459-foot cliff (140 meters) north of the crater.

About a year later, a helicopter pilot flying over the volcano noticed a mysterious green pool of water in the Halema‘uma‘u crater. A second report of the same findings from a helicopter passenger prompted USGS-Hawaiian Volcano Observatory researchers to survey the green pool of water.

It was then discovered that water had indeed started to pool into the lowest part of the Halema'uma'u crater, and ever since the water was discovered in 2019, the depth of the lake has been steadily growing.


© Provided by AccuWeather
The sequence of satellite images above shows Halema‘uma‘u crater before the lava lake drained (left), after the caldera floor had collapsed (middle) and after water pooled on the crater floor for nine months (right). (Joshua Stevens / Landsat data from the U.S. Geological Survey)

"We know that the crater floor dropped a little more than 70 meters below the water table in 2018. Any time that you punch a hole below the level of the water table, water is eventually going to come in and fill that hole," explained Don Swanson, a volcanologist at the U.S. Geological Survey's Hawaiian Volcano Observatory.


© Provided by AccuWeather
The pool of water in the Halemaʻumaʻu Crater on Aug. 7, 2019. (USGS / D. Swanson)

Currently, the water has an area larger than five football fields combined and is approximately 100 feet (30 meters) deep, according to NASA's Earth Observatory.

The water has also changed color from the original chalky green to a rusty brown, due to chemical reactions happening in the water.


© Provided by AccuWeather
The pool of water in the Halemaʻumaʻu Crater on April 21, 2020. Since its discovery in 2019, the pool has slowly been growing. (USGS / M. Patrick)

As for how the water could affect a future eruption of the volcano, Swanson said it could contribute to an explosive eruption, since one of the main factors behind a big volcanic explosion is the amount of water and other gases that get caught up inside the magma.

"In one case, magma could rise quickly up the conduit and intersect with the lake," said Swanson. "In the second, the crater floor could collapse and drop all of the water down to a zone where it would be quickly heated into steam."

While an explosive eruption remains possible for Kilauea, Swanson said the next eruption could also happen slowly and all the water could evaporate.

"We do not want to be alarmist, but we also need to point out to the public that there is an increasing possibility of explosive eruptions at Kilauea," said Swanson.

Only time will tell what is in store for Kilauea, but for now, the volcano is being closely researched and monitored by geologists.

Keep checking back on AccuWeather.com and stay tuned to the AccuWeather Network on DirecTV, Frontier and Verizon Fios.
Moon's mysterious disappearance 900 years ago finally gets an explanation
Brandon Specktor, Live Science

There's no use sugar coating it: According to one scribe in medieval England, A.D. 1110 was a "disastrous year." Torrential rainfall damaged crops, famine stalked the land — and, as if that wasn't bad enough, on one fateful night in May, the moon simply vanished from the sky.
© Jon Nazca The full moon rises between clouds above Ronda, southern Spain, on May 7, 2020.

"On the fifth night in the month of May appeared the moon shining bright in the evening, and afterwards by little and little its light diminished," the unnamed scribe wrote in the Anglo-Saxon manuscript known as the Peterborough Chronicle. "As soon as night came, it was so completely extinguished withal, that neither light, nor orb, nor anything at all of it was seen. And so it continued nearly until day, and then appeared shining full and bright."


Clouds weren't the problem; if they were, the scribe would not go on to describe how bright and twinkling the stars appeared while the moon faded from view. Nor was the moon being eclipsed by Earth's shadow — if it was, the skywatcher would have seen the orb become a coppery "blood moon," not an eerie blank spot in the sky.

Related: Amazing photo reveals a lunar eclipse like you've never seen before

So, what made the moon disappear in an already dismal year? According to a study published April 21 in the journal Scientific Reports, the explanation for both the moon's mysterious vanishing act and the rain-ravaged summer that followed may be one and the same — volcanoes.

"The spectacular atmospheric optical phenomena associated with high-altitude volcanic aerosols have caught the attention of chroniclers since ancient times," the study authors wrote. "Careful evaluation of ice core records points to the occurrence of several closely spaced volcanic eruptions," which may have occurred in Europe or Asia between A.D. 1108 and A.D. 1110.

Those volcanic events, which the researchers call a "forgotten cluster" of eruptions because they were sparsely documented by historians at the time, may have released towering clouds of ash that traveled far around the world for years on end. Not only could a high-altitude veil of volcanic aerosols blot out the moon while leaving many stars unobscured, as the Peterborough writer described, but a series of large eruptions could have also disrupted the global climate, the researcher wrote, causing or exacerbated the cold, wet weather that made life so miserable in A.D. 1110.

One such eruption, which occurred in Japan in A.D. 1108, could be to blame, the team said.
Hunting for the 'forgotten'

For evidence of these "forgotten" eruptions, the researchers looked at ice cores from Greenland and Antarctica — long tubes of ancient ice that can reveal what the global climate looked like at the time, as well as what sorts of particles were floating around in the atmosphere. The team saw an increase in sulfate aerosols (a component of volcanic ash) in both cores between A.D. 1108 and A.D. 1110, suggesting that the stratosphere was sprinkled with fumes from a recent eruption.

The team found further evidence of volcanic activity in tree rings dating from the same period. The rings, which change thickness in response to climate patterns, revealed that 1109 was an unusually cold, wet year in Western Europe — a climatic "anomaly" comparable to the effects of several other major volcanic eruptions from history, the researchers said. The team also tracked down 13 narrative accounts of adverse weather, crop failure and famine from that time period, further supporting the theory that a series of eruptions had slammed Europe's climate.

"The sources of these eruptions remain unknown," the team wrote, "yet one eruption with a historical date in this period is that of Mount Asama in Japan."

According to a diary the team examined, written by a Japanese statesman between 1062 and 1141, the eruption of Mount Asama in central Japan began in late August 1108 and lasted until October of that year.

This eruption, which the statesman described as throwing fire into the sky and rendering nearby fields unfit for cultivation, could have plausibly contributed to the sulfate spike in the Greenland ice core and polluted the sky with enough aerosols to induce the eclipse two years later, the team wrote. (Another unknown eruption, located somewhere in the southern hemisphere and also dating to 1108, likely contributed to the sulfates in the Antarctic ice core, the researchers added.)

While this explanation relies on a lot of "indirect" evidence, the researchers said, it still provides the best solution yet for the case of the disappearing moon.
Ominous trend in American West could signal a looming "megadrought"

CBSNews

Come spring, the American West's vast water reservoirs are supposed to fill with melting snow. However, this year, as in recent years, the large reservoirs of Lake Mead and Lake Powell in the Colorado River basin area have seen declining water levels — an ominous trend that a new study warns could signal a looming megadrought.


"The persistence of the drought conditions, in the Colorado River basin especially, is essentially unprecedented in human history," John Fleck, author of "Water is for Fighting Over," told CBS News' John Blackstone.

Fleck has spent years studying the Colorado River, a crucial source of water for much of the region around it. He said that Lake Mead and Lake Powell's reservoirs have what he described as "big bathtub rings" around them, left behind as the water declines.

"There is less water in the system now than there was 20 and 30 years ago," he said.

Fleck explained that a "wet year" every few years may seem like the drought is ending, but those years are still comparatively lower than decades before.

"When we do get a snowpack in the mountains over winter, we are seeing less water make it into the rivers, and downstream to the farms and cities and the fish and the ecosystems that depend on the water," he said. 
© Provided by CBS News Lake Powell is shown from an airplane window on March 30, 2015, in Page, Arizona.

A team of scientists is researching megadroughts that have lasted as long as 40 years, using tree ring evidence going back 1,200 years.

"If they go back in time 500 years or so, there were these phenomenal droughts — in terms of both severity and in terms of length," Park Williams, the scientist leading the research, said. "And until recently, those droughts have always been spoken about with almost a mythical-type character."

Williams said the drought of the last two decades "developed the same way that the megadroughts did."

However, the key difference now is climate change's effect on weather conditions in the area, which largely depends on melting snowpacks to fill reservoirs.

"Without human-caused climate change, we would still have a drought," Williams said. "But it wouldn't be a serious as the one we've actually seen."

NASA-run project SnowEx has researchers in the mountains of Idaho developing remote sensing equipment to get accurate snowpack measurements from space in order to determine how much water they will produce.

"It's becoming more challenging for us to not only predict how much water is going to enter our reservoirs, but also the ability to store that water all the way through the end of the summer for agriculture and water resource purposes," said Hans Peter Marshall, a scientist working on the project.

The shifting patterns and increased difficulty are some of the main reasons researchers are seeking to develop a space-borne approach to monitor the region's water.

"We're really needing an approach that maps the amount of water that's stored within the snowpack," he said.

It’s already getting too hot and humid in some places for humans to survive


A combination of heat and humidity so extreme that it’s unendurable isn’t just a problem for the future — those conditions are already here, a new study finds. Off-the-chart readings that were previously thought to be nearly nonexistent on the planet today have popped up around the globe, and unyielding temperatures are becoming more common


© Photo by Peter Macdiarmid/Getty Images

Extreme conditions reaching roughly 115 degrees Fahrenheit on the heat-index scale — a measurement of both heat and humidity that’s often referred to as what the temperature “feels like” — doubled between 1979 and 2017, the study found. Humidity and heat are a particularly deadly combination, since humidity messes with the body’s ability to cool itself off by sweating. The findings imply that harsh conditions that scientists foresaw as an impending result of climate change are becoming reality sooner than expected.

“We may be closer to a real tipping point on this than we think”

“We may be closer to a real tipping point on this than we think,” Radley Horton, co-author of the new study published today in the journal Science Advances, said in a statement. His previous research had projected that the world wouldn’t experience heat and humidity beyond human tolerance for decades.

More intense and frequent heat events are one of the symptoms of climate change, a lot of research has shown. But most of those studies were based on readings that looked at averages over a wide area over a long period of time. Instead, Horton and his co-authors looked closely at hourly data from 7,877 weather stations around the world. They used the “wet bulb” centigrade scale, which measures other factors such as wind speed and solar radiation on top of heat and humidity.

That’s how they found more than a thousand readings of severe heat and humidity, reaching wet bulb readings of 31 degrees Celsius, that were previously thought to be very rare. Along the Persian Gulf, they saw more than a dozen readings above what’s thought to be the human tolerance limit of 35 degrees Celsius on the wet bulb scale. That’s the highest wet bulb reading that scientific literature has ever documented. In 2015, the city of Bandar Mahshahr in Iran experienced a wet bulb reading just under 35 degrees Celsius. At more than 160 degrees Fahrenheit on the heat-index scale, that’s about 30 degrees higher than where the National Weather Service’s heat-index range ends — and it’s a scenario that climate models hadn’t forecast to happen until the middle of the century.

Spells of extreme humid heat were also witnessed across Asia, Africa, Australia, South America, and North America and were generally clustered along the coasts. The US Gulf Coast was particularly hard-hit. The region saw dozens of instances of conditions reaching levels not expected to take place for decades. Severe conditions only lasted hours and were often only in small areas, but these bouts are becoming more frequent and more intense, the researchers say.

They make the case that future studies ought to take a similarly localized look to get a better understanding of how climate change is playing out in communities that will feel the crunch ahead of the rest of the world. A Pulitzer prize-winning series by The Washington Post took this sort of approach in a series about places where average temperatures have already risen 2 degrees Celsius, the threshold at which the Paris climate accord aims to keep the globe from surpassing.

“At the smallest scale, it’s more intense.”

“If you zoom in you see things that you don’t see at a larger scale,” says Colin Raymond, lead author and a postdoctoral researcher at NASA’s Jet Propulsion Laboratory. “At the smallest scale, it’s more intense.” One of the limitations to their study, according to Raymond, is that there are places across the globe that simply lack weather stations. So what they were able to document could be happening at an even wider scale, there just aren’t tools in place yet to make those measurements everywhere.

Extreme heat already kills more people in the US than any other weather-related event.

In 50 years, between 1 to 3 billion people could find themselves living in temperatures so hot that they’re outside the range in which humans have been able to thrive, found another study published this week. Just how many billions will face that future depends on what action is taken now to stop the planet from dangerously overheating.



Potentially lethal heat waves are happening more often

QUARTZ


Last July, a deadly extreme heat wave ripped across the United States. Triple-digit temperatures caused widespread power outages and at least half a dozen deaths. In many places, the temperatures were made even more excruciating by high humidity, which limits the cooling effect of evaporating sweat. In Baltimore, the heat index—a measure used by meteorologists to account for heat and humidity—hit 122 degrees Fahrenheit.

But that kind of extreme is just the tip of the iceberg, according to research published today in the journal Science Advances. Combing global weather records at an unusually fine level of detail, climatologists at Columbia University found that globally, combined extreme heat and humidity events are occurring more frequently, even more so than scientists previously thought. The tally includes a small but growing number of instances where heat and humidity conditions reached levels that would be deadly to most people.

The study focused on a metric called wet bulb temperature, which is similar to heat index and also combines heat and humidity. Because of how they are calculated, wet bulb temperatures are typically lower than the ambient air temperature, even though humidity makes heat feel more intense. A typical summer day in New York City has a wet bulb temperature in the low 70s F (low 20s C); Baltimore’s 2019 heat wave maxed out at around 30°C (86°F) wet bulb temperature.


Between 1979 and 2017, the frequency of instances of wet bulb temperatures at or above 27°C (81°F) has more than doubled, the study found, mostly in coastal areas. Instances over 29°C more than tripled. Locations in the Middle East, South Asia, and the Gulf of California have even hit 35°C (95°F)—the highest level documented on Earth, and what physiologists see as the limit of human survival—an increasing number of times. 

Altogether, the study unearthed 1.7 million instances of a wet bulb temperature at or above 27°C. Many of these were brief, spanning just hours. For that reason, they are easily lost in most global weather analyses, which aggregate hourly data from thousands of weather stations to understand long-term trends.

Climate change models have projected an increase in these kinds of extreme heat and humidity later in the century; a 2018 special report by the Intergovernmental Panel on Climate Change projects that in a mid-range warming scenario, 1-in-20-year temperature extremes could happen once every other year. But these findings suggest that extreme highs are already happening regularly now.

“There’s nothing wrong with those models,” said Colin Raymond, the study’s lead author, who began the research as a climatology doctoral student at Columbia and is now a postdoc studying climate at NASA. “But they didn’t really capture the baseline of what’s happened in last 40 years because they were using data that was too smoothed out to represent brief localized extremes.”

The places at highest risk for extreme heat and humidity, the study found, were coastal desert areas at mid-latitudes, near gulfs and other relatively warm bodies of water. There, unlike at the equator, heat and humidity are able to build up without triggering tropical storms that release humidity from the air in the form of precipitation. The worst conditions were found in Saudi Arabia, Qatar, and the United Arab Emirates.

Compared to other weather events like droughts and hurricanes, extreme heat is one of the best-understood impacts of climate change; scientists are highly confident that instances of extreme heat will rise in tandem with average global temperatures. Eight of the 10 hottest years on record have happened since 2010; 2020 is on track to be in the top five, said Kristy Dahl, a climatologist at the Union of Concerned Scientists.

That could be a serious problem during the Covid-19 pandemic, especially because the elderly and others most vulnerable to the disease are the same people most susceptible to heat stress. Despite a claim in April by Department of Homeland Security researchers that sunlight and humidity can be detrimental to the virus, an analysis by the National Academies of Science found there’s little reason to expect a significant summer slowdown in transmission.

“It wouldn’t be surprising if we have intense heat waves this summer,” Dahl said. “But all the places cities will often open to keep people cool—cooling centers, libraries, museums, shopping malls, movie theaters—all of those are off-limits right now.”

Raymond said a step for future research will be to add more variables, including breeze and sunshine, on top of heat and humidity, for a more complete picture of what these conditions really feel like, as well as including more data from sub-Saharan Africa and other regions that aren’t covered as well by weather stations.

As for researching the feeling of a 35°C wet bulb temperature first hand, Raymond said he’ll pass.

“It’s beyond what anyone who hasn’t experienced it can really imagine,” he said. “The heat and humidity of the American south pales in comparison to the steam-room atmosphere that we’re seeing around the Persian Gulf and Red Sea.”