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'Earthshine' is dimming and that's bad news for the climate – The Weather Network

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Earthshine is one of the most spectacular sights in our night sky. Yet, this astronomical phenomenon is slowly vanishing, and this is providing us with a new warning sign for the climate.

Gaze up at a thin Crescent Moon as it hangs above the horizon, and you will often be able to dimly make out the features that are immersed in the shadow of the Moon’s dark side. This phenomenon is known as Earthshine.

Sunlight reflected from Earth shines upon the Moon’s dark side, in a phenomenon called Earthshine. Credit: Science@NASA

Earthshine results from Earth’s albedo. Of all the incoming sunlight that reaches Earth, roughly one-third gets directly reflected back into space by bright cloud tops and icy surfaces.

Some of this reflected sunlight shines onto the Moon’s surface. This effect is best seen just before and just after a New Moon. That’s when the greatest amount of dark lunar surface is lit by the greatest amount of reflected light from Earth. Anyone looking up at the Moon on those nights will be able to pick out the most prominent features of the lunar surface, even though they are not lit by the direct light of the Sun.

Earth, Moon & Earthshine - NASAViewing the Moon from Earth and Earth from the Moon during any month reveals how their phases are complementary. As shown in this image, anyone standing on the lunar surface during a thin Crescent Moon would see a brightly lit “nearly full” Earth. Credit: NASA

However, according to a new study, this phenomenon is slowly disappearing.

Researchers gathered two decades worth of observations of Earthshine, from 1998 to 2017, taken at the Big Bear Solar Observatory, in San Bernardino National Forest, east of Los Angeles, California. The data they collected revealed that Earthshine had dimmed over that time, by about 0.5 per cent. Since the dimming they observed did not match up with changes in the Sun’s brightness during that same time period, that means the dimming is being caused by Earth.

In other words, Earth’s albedo is decreasing, thus the planet is now reflecting less sunlight back into space than it was 20 years ago.

“The albedo drop was such a surprise to us when we analyzed the last three years of data after 17 years of nearly flat albedo,” Philip Goode, the lead researcher on the study from the New Jersey Institute of Technology, said in a press release from the American Geophysical Union (AGU).

Earthshine-2001-2019-AGU-Goode-et-al-Geophysical-Research-LettersThis graph shows two decades worth of Earthshine data (black points), alongside data from NASA’s Clouds and the Earth’s Radiant Energy System (CERES) instruments in orbit (blue points). Both reveal that Earth’s albedo is decreasing. CERES detected a significant drop in albedo in 2019. Credit: Goode et al. (2021), Geophysical Research Letters.

While the slow disappearance of Earthshine would be terrible for stargazers, there is a much more significant and troubling impact from this discovery.

Over the years, one of the uncertainties in Earth’s climate system has been whether rising ocean temperatures would increase or decrease cloud cover.

If it increased cloud cover, it could create a self-limiting effect on climate change. Greater cloud cover would increase the amount of sunlight being reflected back into space. As a result, with less sunlight reaching the surface, it would reduce the amount of heat being added to the climate system.

On the other hand, if warming oceans resulted in less cloud cover, it would lower the planet’s albedo. More sunlight would reach the ground, which would result in more heat being added to the climate system. Over time, this would increase the rate of global warming and make the impacts of climate change worse.

Earthshine - ISS028-E-20073 - NASAPhotographed from the International Space Station on July 31, 2011, this image shows the Crescent Moon shining above the limb of Earth, along with the different layers of the atmosphere (troposphere in orange, stratosphere in blue, fading into the mesosphere). The dark side of the Moon is dimly illuminated by the phenomenon of Earthshine. Credit: NASA

This new study found that, along with the detected decrease in Earthshine from their observations, NASA’s Clouds and the Earth’s Radiant Energy System (CERES) project also saw a reduction in the amount of cloud cover over the eastern Pacific Ocean. The CERES instruments, carried by NASA’s Terra and Aqua satellites, found fewer bright, low-lying clouds over a region of the Pacific Ocean off the west coasts of North and South America.

This reduction in clouds is over a region of the ocean where previous studies have shown sea surface temperatures to be on the rise. The increase in temperatures is likely due to changes in a large-scale climate pattern known as the Pacific Decadal Oscillation (PDO).

Pacific Decadal Oscillation - PDO - Sea Surface Temps map - NOAA Climate

Thus, based on the findings of this study, it would appear that warmer oceans are reducing the amount of cloud cover, which is very bad news.

Also, although the drop in albedo is only 0.5 per cent, the amount of extra heat it adds to our climate system is nearly the same as what human activity added over the same time period.

“The two-decade decrease in earthshine-derived albedo corresponds to an increase in radiative forcing of about 0.5 Watts per square metre, which is climatologically significant,” the researchers wrote. “For comparison, total anthropogenic forcing increased by about 0.6 Watts per square metre over the same period.”

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Guilt, grief and anxiety as young people fear for climate’s future

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Overwhelmed, sad, guilty are some of the emotions young people say they feel when they think of  Climate Change and their concerns world leaders will fail to tackle it.

Broadly referred to as climate anxiety, research has stacked up to measure its prevalence ahead of the U.N. talks in Glasgow, which begin at the end of the month to thrash out how to put the 2015 Paris Agreement on curbing climate change into effect.

One of the biggest studies to date, funded by Avaaz, an online campaign network, and led by Britain’s University of Bath, surveyed 10,000 young people aged 16-25 years in 10 countries. It published its results in September.

It found around three quarters of those surveyed considered the future frightening, while a lack of action by governments and industry left 45% experiencing climate anxiety and distress that affected their daily lives and functioning.

Elouise Mayall, an ecology student at Britain’s University of East Anglia and member of the UK Youth Climate Coalition, told Reuters she had felt guilty and overwhelmed.

“What I’d be left with is maybe the sense of shame, like, ‘how dare you still want lovely things when the world is ending and you don’t even know if you’re going to have a safe world to grow old in’.”

She spoke of conflicting emotions.

“You might have sadness, there might be fear, there might be a kind of overwhelm,” she said. “And maybe even sometimes a quite like wild optimism.”

Caroline Hickman, a psychotherapist and lecturer at the University of Bath and one of the co-authors of the research published in September, is working to help young people manage climate-related emotions.

“They’re growing up with the grief and the fear and the anxiety about the future,” she told Reuters.

“SENSE OF MEANING”

London-based psychiatrist Alastair Santhouse sees climate change, as well as COVID-19, as potentially adding to the burden, especially for those pre-disposed to  anxiety .

For now, climate anxiety alone does not normally require psychiatric help. Painful as it is, it can be positive, provided it does not get out of control.

“Some anxiety about climate change is motivating. It’s just a question of how much anxiety is motivating and how much is unacceptable,” said Santhouse, author of a book that tackles how health services struggle to cope with complex mental issues.

“The worry is that as climate change sets in, there will be a more clear cut mental health impact,” he added.

Among some of the world’s communities that are already the most vulnerable, extreme weather events can also cause problems such as post traumatic stress disorder.

Leading climate campaigner Greta Thunberg, 18, has experienced severe climate anxiety.

“It’s a quite natural response, because, as you see, as the world is today, that no one seems to care about what’s happening, I think it’s only human to feel that way,” she said.

For now, however, she is hopeful because she is doing everything she possibly can.

“When you take action, you also get a sense of meaning that something is happening. If you want to get rid of that anxiety, you can take action against it,” she said.

 

(Reporting by Barbara Lewis; Editing by Alison Williams)

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Rocket failure mars U.S. hypersonic weapon test as others succeed

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The Pentagon ‘s hypersonic weapon programs suffered a setback on Thursday when a booster rocket carrying a hypersonic weapon failed, people briefed on the test result said.

The test was intended to validate aspects of one of the Pentagon’s hypersonic glide vehicles in development, two of the people said.

Hypersonic glide vehicles are launched from a rocket in the upper atmosphere before gliding to a target at speeds of more than five times the speed of sound, or about 3,853 miles (6,200 kilometers) per hour.

In a separate series of tests conducted on Wednesday, the U.S. Navy and Army tested hypersonic weapon component prototypes. That test successfully “demonstrated advanced hypersonic technologies, capabilities, and prototype systems in a realistic operating environment,” the Pentagon said in a statement.

The United States and its global rivals have quickened their pace to build hypersonic weapons – the next generation of arms that rob adversaries of reaction time and traditional defeat mechanisms.

U.S. President Joe Biden expressed concern on Wednesday about Chinese hypersonic missiles, days after a media report that Beijing had tested a nuclear-capable hypersonic glide weapon.

Glide bodies are different from their air-breathing hypersonic weapon cousins which use scramjet engine technology and the vehicle’s high speed to forcibly compress incoming air before combustion to enable sustained flight at hypersonic speeds. An air-breathing hypersonic weapon was successfully tested in September.

Companies such as Lockheed Martin and Raytheon Technologies are working to develop the hypersonic weapon capability for the United States.

(Reporting by Mike Stone and Idrees Ali in Washington; Editing by Sandra Maler)

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Patagonian fossils show Jurassic dinosaur had the herd mentality | Saltwire – SaltWire Network

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By Will Dunham

(Reuters) – A vast trove of fossils unearthed in Argentina’s southern Patagonia region is offering the oldest-known evidence that some dinosaurs thrived in a complex and well-organized herd structure, with adults caring for the young and sharing a communal nesting ground.

Scientists said on Thursday the fossils include more than 100 dinosaur eggs and the bones of about 80 juveniles and adults of a Jurassic Period plant-eating species called Mussaurus patagonicus, including 20 remarkably complete skeletons. The animals experienced a mass-death event, probably caused by a drought, and their bodies were subsequently buried by wind-blown dust, the researchers said.

“It is a pretty dramatic scene from 193 million years ago that was frozen in time,” said paleontologist Diego Pol of the Egidio Feruglio Paleontological Museum in Trelew, Argentina, who led the research published in the journal Scientific Reports.

Mussaurus, which grew to about 20 feet (6 meters) long and about 1.5 tons, possessed a long neck and tail, with a small head. It was bipedal as an adult but newborns were quadrupedal. Mussaurus lived early in the Jurassic, the second of three periods comprising the age of dinosaurs. It was a relatively large beast for its time – much bigger than contemporaneous meat-eating dinosaurs. Dinosaurs became true giants later in the Jurassic.

“The site is one of a kind,” Pol said. “It preserves a dinosaur nesting ground including delicate and tiny dinosaur skeletons as well as eggs with embryos inside. The specimens we have found showed that herd behavior was present in long-necked dinosaurs since their early history. These were social animals, and we think this may be an important factor to explain their success.”

The animals were found to have been grouped by age at the time of their deaths, with hatchlings and eggs in one area while skeletons of juveniles were clustered nearby. The eggs were arranged in layers within trenches. Adults were found alone or in pairs.

This phenomenon, called “age segregation,” signals a complex social structure, the researchers said, including adults that foraged for meals and cared for the young. The researchers suspect that members of the herd returned to the same spot during successive seasons to form breeding colonies.

“The young were staying with the adults at least until they reached adulthood. It could be that they stayed in the same herd after reaching adulthood, but we don’t have information to corroborate that hypothesis,” said paleontologist and study co-author Vincent Fernandez of the Natural History Museum in London.

Herd behavior also can protect young and vulnerable individuals from attack by predators.

“It’s a strategy for the survival of a species,” Fernandez said.

The oldest previous evidence for dinosaur herd behavior was from about 150 million years ago.

The nesting ground was situated on the dry margins of a lake featuring ferns and conifers in a warm but seasonal climate. The eggs are about the size of a chicken’s, and the skeleton of a hatchling fits in the palm of a human hand. The adults got as heavy as a hippo.

A scanning method called high-resolution X-ray computed tomography confirmed that the embryos inside the eggs indeed were of Mussaurus.

Mussaurus was a type of dinosaur called a sauropodomorph, which represented the first great success story among herbivorous dinosaurs. Sauropodomorphs were an evolutionary forerunner to a group called sauropods known for long necks and tails and four pillar-like legs.

The largest land animals in Earth’s history were the sauropod successors of sauropodomorphs, as exemplified by a later denizen of Patagonia called Argentinosaurus that reached perhaps 118 feet (36 meters) in length and upwards of 70 tons.

(Reporting by Will Dunham in Washington, Editing by Rosalba O’Brien)

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