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Arctic amplification: How the albedo effect speeds up global warming
The more Greenland melts, the more Greenland melts. Here's why.
JON GERTNER: One thing that's particularly worrisome about the Arctic right now is that it's warming about twice as fast as the rest of the world. And there's this term scientists use for it, called arctic amplification. So whereas the rest of the Earth on average has warmed about 1 degree centigrade since pre-industrial era, the Arctic is more like 2 degrees centigrade. And some places in Greenland Pronounced, and in Siberia, too. There are two really worrisome results from this. One is that the ice that covers the Arctic, the sea ice, this is floating sea ice, that goes over the North Pole and around the Arctic Ocean has been decreasing dramatically over the past 20 years.
In fact, this is probably the greatest sort of most significant natural change to ecosystems on Earth since human beings have been around. It's declined by somewhere between a third and half. What that means is that as the ice sort of decreases, the albedo of the Arctic changes. Ice, of course, is white and bright, and it reflects solar energy back into space. When it exposes dark, open ocean, that open ocean absorbs more sunlight and more energy. And it creates a kind of feedback loop that the more ocean that's exposed, the more energy that's absorbed, the more heat that's actually absorbed as well. And it kind of builds on itself. So it feels like the-- it is true, the more Arctic ice that we lose, it seems, the more we are in danger of losing more Arctic ice. And right now the summer time melt is about at record levels.
The sea ice sort of reaches a low point by late August, and almost every year it's either at record levels or near record levels in terms of how much has been lost. When we lose sea ice we don't raise sea levels. It's like ice melting in a glass, it just melts. It has negative effects, but it doesn't flood our cities. However, the other problem of the warming Arctic is that Greenland's ice and Greenland's ice sheet, when it melts it does drip into the ocean, and it does add mass to the ocean, and does raise sea levels. And it does create this kind of future of floods. And the same goes for Antarctica on the other side of the Earth. Greenland, Greenland is vulnerable to similar kinds of feedback loops that the Arctic ice For instance, as Greenland melts, the altitude of the ice, this big dome of ice gets lower down.
And at lower altitudes there are warmer temperatures. So the more Greenland melts on top, the more the altitude of the ice sheet declines, and the more vulnerable that is to summertime melt. At the same time, over the last few years especially, scientists have noticed that the ice sheet is getting darker. Especially on this strip of western ice kind of near the southwestern coast. And this darkness is caused by a couple of things. One, sometimes it's lack of snow cover. Ice is actually darker than snow, and we have fresh snow, you have a very bright reflective surface. But I think more crucially what's happening is that there's kind of algae and other organisms that are growing on the ice sheet that lend it a darkness. And there's also sort of carbon soot that's deposited there. And I've been on the ice sheet several times. And when you think of the ice sheet, you think of maybe it's, oh, it's like a skating rink, or it's like being on a kind of ski slope.
And in some parts it feels like being on a kind of snowy field. But in a lot of parts, especially on the west, it's like being on top of brittle, dirty ice. And you look down and you can actually see these kinds of dark, strange pockets within. And there are a number of scientists that are doing experiments on those. There's a British team that's called-- that's doing something called Black and Bloom. And they've discerned a kind of vast, kind of natural ecosystem of algae and bacteria that's growing on the Greenland ice sheet every year, especially in summer when it comes back.
The takeaway here is that the darkness absorbs more solar energy and more sunlight. It accelerates the melt of the ice. When we talk about how if Greenland's ice sheet gets darker it melts more, and if it melts more it gets darker. All of which is to say that these feedback loops create this kind of difficult proposition that the more Greenland melts, the more Greenland melts.
- The Arctic right is currently warming about twice as fast as the rest of the world.
- Ice is white and bright and is able to reflect solar energy back into space. When it melts and exposes dark, open ocean, that open ocean absorbs more sunlight and more energy. This creates a kind of feedback loop.
- The darkness absorbs more solar energy — more sunlight. In turn, this accelerates the melt of the ice.
- Greenland loses 4 trillion pounds of ice in one day - Big Think ›
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Duke University researchers might have solved a half-century old problem.
- Duke University researchers created a hydrogel that appears to be as strong and flexible as human cartilage.
- The blend of three polymers provides enough flexibility and durability to mimic the knee.
- The next step is to test this hydrogel in sheep; human use can take at least three years.
Duke researchers have developed the first gel-based synthetic cartilage with the strength of the real thing. A quarter-sized disc of the material can withstand the weight of a 100-pound kettlebell without tearing or losing its shape.
Photo: Feichen Yang.<p>That's the word from a team in the Department of Chemistry and Department of Mechanical Engineering and Materials Science at Duke University. Their <a href="https://onlinelibrary.wiley.com/doi/abs/10.1002/adfm.202003451" target="_blank">new paper</a>, published in the journal,<em> Advanced Functional Materials</em>, details this exciting evolution of this frustrating joint.<br></p><p>Researchers have sought materials strong and versatile enough to repair a knee since at least the seventies. This new hydrogel, comprised of three polymers, might be it. When two of the polymers are stretched, a third keeps the entire structure intact. When pulled 100,000 times, the cartilage held up as well as materials used in bone implants. The team also rubbed the hydrogel against natural cartilage a million times and found it to be as wear-resistant as the real thing. </p><p>The hydrogel has the appearance of Jell-O and is comprised of 60 percent water. Co-author, Feichen Yang, <a href="https://today.duke.edu/2020/06/lab-first-cartilage-mimicking-gel-strong-enough-knees" target="_blank">says</a> this network of polymers is particularly durable: "Only this combination of all three components is both flexible and stiff and therefore strong." </p><p> As with any new material, a lot of testing must be conducted. They don't foresee this hydrogel being implanted into human bodies for at least three years. The next step is to test it out in sheep. </p><p>Still, this is an exciting step forward in the rehabilitation of one of our trickiest joints. Given the potential reward, the wait is worth it. </p><p><span></span>--</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
An algorithm may allow doctors to assess PTSD candidates for early intervention after traumatic ER visits.
- 10-15% of people visiting emergency rooms eventually develop symptoms of long-lasting PTSD.
- Early treatment is available but there's been no way to tell who needs it.
- Using clinical data already being collected, machine learning can identify who's at risk.
The psychological scars a traumatic experience can leave behind may have a more profound effect on a person than the original traumatic experience. Long after an acute emergency is resolved, victims of post-traumatic stress disorder (PTSD) continue to suffer its consequences.
In the U.S. some 30 million patients are annually treated in emergency departments (EDs) for a range of traumatic injuries. Add to that urgent admissions to the ED with the onset of COVID-19 symptoms. Health experts predict that some 10 percent to 15 percent of these people will develop long-lasting PTSD within a year of the initial incident. While there are interventions that can help individuals avoid PTSD, there's been no reliable way to identify those most likely to need it.
That may now have changed. A multi-disciplinary team of researchers has developed a method for predicting who is most likely to develop PTSD after a traumatic emergency-room experience. Their study is published in the journal Nature Medicine.
70 data points and machine learning
Image source: Creators Collective/Unsplash
Study lead author Katharina Schultebraucks of Columbia University's Department Vagelos College of Physicians and Surgeons says:
"For many trauma patients, the ED visit is often their sole contact with the health care system. The time immediately after a traumatic injury is a critical window for identifying people at risk for PTSD and arranging appropriate follow-up treatment. The earlier we can treat those at risk, the better the likely outcomes."
The new PTSD test uses machine learning and 70 clinical data points plus a clinical stress-level assessment to develop a PTSD score for an individual that identifies their risk of acquiring the condition.
Among the 70 data points are stress hormone levels, inflammatory signals, high blood pressure, and an anxiety-level assessment. Says Schultebraucks, "We selected measures that are routinely collected in the ED and logged in the electronic medical record, plus answers to a few short questions about the psychological stress response. The idea was to create a tool that would be universally available and would add little burden to ED personnel."
Researchers used data from adult trauma survivors in Atlanta, Georgia (377 individuals) and New York City (221 individuals) to test their system.
Of this cohort, 90 percent of those predicted to be at high risk developed long-lasting PTSD symptoms within a year of the initial traumatic event — just 5 percent of people who never developed PTSD symptoms had been erroneously identified as being at risk.
On the other side of the coin, 29 percent of individuals were 'false negatives," tagged by the algorithm as not being at risk of PTSD, but then developing symptoms.
Image source: Külli Kittus/Unsplash
Schultebraucks looks forward to more testing as the researchers continue to refine their algorithm and to instill confidence in the approach among ED clinicians: "Because previous models for predicting PTSD risk have not been validated in independent samples like our model, they haven't been adopted in clinical practice." She expects that, "Testing and validation of our model in larger samples will be necessary for the algorithm to be ready-to-use in the general population."
"Currently only 7% of level-1 trauma centers routinely screen for PTSD," notes Schultebraucks. "We hope that the algorithm will provide ED clinicians with a rapid, automatic readout that they could use for discharge planning and the prevention of PTSD." She envisions the algorithm being implemented in the future as a feature of electronic medical records.
The researchers also plan to test their algorithm at predicting PTSD in people whose traumatic experiences come in the form of health events such as heart attacks and strokes, as opposed to visits to the emergency department.
What would it be like to experience the 4th dimension?
Physicists have understood at least theoretically, that there may be higher dimensions, besides our normal three. The first clue came in 1905 when Einstein developed his theory of special relativity. Of course, by dimensions we’re talking about length, width, and height. Generally speaking, when we talk about a fourth dimension, it’s considered space-time. But here, physicists mean a spatial dimension beyond the normal three, not a parallel universe, as such dimensions are mistaken for in popular sci-fi shows.
Vaccines find more success in development than any other kind of drug, but have been relatively neglected in recent decades.
Vaccines are more likely to get through clinical trials than any other type of drug — but have been given relatively little pharmaceutical industry support during the last two decades, according to a new study by MIT scholars.