Reduced energy from the sun might occur by mid-century: Now scientists know by how much

The Sun might emit less radiation by mid-century, giving planet Earth a chance to warm a bit more slowly but not halt the trend of human-induced climate change.

The cooldown would be the result of what scientists call a grand minimum, a periodic event during which the Sun's magnetism diminishes, sunspots form infrequently, and less ultraviolet radiation makes it to the surface of the planet. Scientists believe that the event is triggered at irregular intervals by random fluctuations related to the Sun's magnetic field.

Scientists have used reconstructions based on geological and historical data to attribute a cold period in Europe in the mid-17th Century to such an event, named the "Maunder Minimum." Temperatures were low enough to freeze the Thames River on a regular basis and freeze the Baltic Sea to such an extent that a Swedish army was able to invade Denmark in 1658 on foot by marching across the sea ice.

A team of scientists led by research physicist Dan Lubin at Scripps Institution of Oceanography at the University of California San Diego has created for the first time an estimate of how much dimmer the Sun should be when the next minimum takes place.

There is a well-known 11-year cycle in which the Sun's ultraviolet radiation peaks and declines as a result of sunspot activity. During a grand minimum, Lubin estimates that ultraviolet radiation diminishes an additional seven percent beyond the lowest point of that cycle. His team's study, "Ultraviolet Flux Decrease Under a Grand Minimum from IUE Short-wavelength Observation of Solar Analogs," appears in the publication Astrophysical Journal Letters and was funded by the state of California.

"Now we have a benchmark from which we can perform better climate model simulations," Lubin said. "We can therefore have a better idea of how changes in solar UV radiation affect climate change."

Lubin and colleagues David Tytler and Carl Melis of UC San Diego's Center for Astrophysics and Space Sciences arrived at their estimate of a grand minimum's intensity by reviewing nearly 20 years of data gathered by the International Ultraviolet Explorer satellite mission. They compared radiation from stars that are analogous to the Sun and identified those that were experiencing minima.

The reduced energy from the Sun sets into motion a sequence of events on Earth beginning with a thinning of the stratospheric ozone layer. That thinning in turn changes the temperature structure of the stratosphere, which then changes the dynamics of the lower atmosphere, especially wind and weather patterns. The cooling is not uniform. While areas of Europe chilled during the Maunder Minimum, other areas such as Alaska and southern Greenland warmed correspondingly.

Lubin and other scientists predict a significant probability of a near-future grand minimum because the downward sunspot pattern in recent solar cycles resembles the run-ups to past grand minimum events.

Despite how much the Maunder Minimum might have affected Earth the last time, Lubin said that an upcoming event would not stop the current trend of planetary warming but might slow it somewhat. The cooling effect of a grand minimum is only a fraction of the warming effect caused by the increasing concentration of carbon dioxide in the atmosphere. After hundreds of thousands of years of CO2 levels never exceeding 300 parts per million in air, the concentration of the greenhouse gas is now over 400 parts per million, continuing a rise that began with the Industrial Revolution. Other researchers have used computer models to estimate what an event similar to a Maunder Minimum, if it were to occur in coming decades, might mean for our current climate, which is now rapidly warming.

One such study looked at the climate consequences of a future Maunder Minimum-type grand solar minimum, assuming a total solar irradiance reduced by 0.25 percent over a 50-year period from 2020 to 2070. The study found that after the initial decrease of solar radiation in 2020, globally averaged surface air temperature cooled by up to several tenths of a degree Celsius. By the end of the simulated grand solar minimum, however, the warming in the model with the simulated Maunder Minimum had nearly caught up to the reference simulation. Thus, a main conclusion of the study is that "a future grand solar minimum could slow down but not stop global warming."

Climate Change Could Turn Earth into Venus: Stephen Hawking

The British physicist said Venus was once an inhabitable Earth-like planet, but greenhouse gases raised its surface temperatures to boiling point – and beyond.

In the second episode of his new series "Stephen Hawking's Favorite Places," the British physicist warns Earth could soon become as hot as Venus if action to halt climate change is not taken immediately.

RELATED: Stephen Hawking Says AI Can 'Outperform Humans'

Hawking says Venus was once an Earth-like planet with surface water, mild temperatures and an appropiate atmosphere. According to NASA, Venus was an inhabitable planet for a period of about two billion years as recently as four billion years ago.

Now temperatues on Venus reach 250°C with powerful 300mph winds. Hawking says a greenhouse effect burned the planet's oceans and lands, and that something similar could happen right here on Earth if climate change continues unabated.

"Next time you meet a climate-change denier, tell them to take a trip to Venus; I will pay the fare," says the physicist in his show.

Hawking has severely criticized Trump's decision last year to pull the United States out of the Paris Agreement. The US president has stated before that this climate pact puts the US economy at a disadvantage, even denying that climate change is a real thing and stating that he cares not for the citizens of Paris, but only those of the United States.

The Paris climate agreement is an international effort to reduce greenhouse gas emissions and was signed by 195 nations in 2015.

In the Starmus Festival last year, Hawking said Trump's decision was "the most serious and wrong decision on climate change this world has seen." He also said that the human race would have to colonize outer space in the next 200 to 500 years if we are to survive as species.

Since then, Hawking has stated multiple times his hopes for a new era of space exploration, in which nations unite toward a single goal.

"It is clear we are entering a new space age. We are standing at the threshold of a new era. Human colonisation and other planets is no longer science fiction, it can be science fact."

The scientist is currently working on Breakthrough Starshot, a project that could send "a ground-based light beamer pushing ultra-light nanocrafts – miniature space probes attached to lightsails – to speeds of up to 100 million miles an hour" to Alpha Centauri, the closest star system, in just 20 years.

"Stephen Hawking's Favorite Places" won an Emmy last year and is available for streaming at Curiosity Stream.

World's first floating city to be built off the coast of French Polynesia by 2020

On-going project making concept of ‘seasteading’ a reality, building a semi-autonomous community at sea and providing an environment relatively free of government control.

Ambitious plans to create a city in the sea, complete with homes, offices and restaurants, are beginning to materialise.

Long touted as the next frontier for humanity by tech billionaires and libertarians, ‘seasteading’ – the idea of building autonomous, self-sustaining cities in international waters – has moved one step closer to reality. 

A pilot project underway in the coastal waters of French Polynesia is set to become the first functioning ‘floating community’ by 2020, offering homes for up to 300 people.

Ambitious plans to create a city in the sea, complete with homes, offices and restaurants, are beginning to materialise.

Long touted as the next frontier for humanity by tech billionaires and libertarians, ‘seasteading’ – the idea of building autonomous, self-sustaining cities in international waters – has moved one step closer to reality. 

A pilot project underway in the coastal waters of French Polynesia is set to become the first functioning ‘floating community’ by 2020, offering homes for up to 300 people.

This floating city will exist in a ‘special economic seazone’, allowing the the Seasteading Institute to try out some of its ideas in a relatively controlled environment. 

Engineers and architects have visited an undisclosed location where the project is set to begin. Their ambitions extend to the creation of a research institute in the floating city, and even a power plant to sell energy and clean water back to their host nation.

The project is projected to cost $167 million.

The team has made a deal with French Polynesia to create a "unique governing framework" in a patch of ocean where their project can begin.

Mr Quirk, who describes himself as a ‘seavangelist’, first became interested in the notion of seasteading at Nevada’s Burning Man festival in 2011. The festival provided him with an idea of the type of unconstrained society he would like to see flourishing in offshore cities.

Another early backer of seasteading, the Silicon Valley billionaire Peter Thiel, has invested $1.7 million in The Seasteading Institute, but has since fallen out of love with the idea.

"They're not quite feasible from an engineering perspective," Mr Thiel told the New York Times in a separate interview. "That's still very far in the future"

Indeed, past efforts to get seasteading off the ground have not been successful, with a prototype planned for the San Francisco Bay in 2010 failing to appear.

But the team behind the Floating Island Project are sure of their new idea, and are currently in the process of demonstrating the project’s viability to the French Polynesian local government.

The Memorandum of Understanding they have signed is based on the seasteaders’ ability to show the positive economic and environmental impact it would have for their host nation.

If that all goes to plan, they anticipate work beginning on development of the pilot project as early as 2018 and beyond that, many more.

“I want to see floating cities by 2050, thousands of them hopefully,” said Mr Quirk.

6th mass extinction event could happen by 2100 – study

Over the past 540 million years Earth has suffered five mass extinction events, the worst of which wiped out more than 9 per cent of marine life on the planet. A new study has suggested that the next such catastrophe might not be too far away.

Massachusetts Institute of Technology (MIT) geophysicist and mathematician, Daniel Rothman has been busy studying previous mass extinctions. He reckons the next one might be a mere 83 years away.

The previous five catastrophic events each unfolded over millions of years and involved the natural cycle of carbon through the oceans and atmosphere being disturbed, resulting, in some cases, the death of almost all life on Earth.

The award-winning mathematician identified two “thresholds of catastrophe” that, if exceeded, would upset the natural order of the cycle, leading to an unstable environment and eventually a mass extinction.

@RT_com Doomsayers watch countdown to Sept 23 ‘Planet X’ event rubbished by https://on.rt.com/8nj5

The first relates to changes in the carbon cycle over a period of thousands or millions of years. A mass extinction will occur if the rate of change in the cycle occurs faster than global ecosystems can adapt.

The second pertains to the size or magnitude of the carbon flux over a shorter period, as has been the case over the last century.

Therein lies a problem, however, as Rothman says“How can you really compare these great events in the geologic past, which occur over such vast timescales, to what's going on today, which is centuries at the longest?”

“So I sat down one summer day and tried to think about how one might go about this systematically.”

@RT_com 'We run out of space, the only places to go to are other worlds' - on space colonization at https://on.rt.com/8fho

Following this, he devised a mathematical formula to determine the total mass of carbon added to the oceans during each event, after which “it became evident that there was a characteristic rate of change that the system basically didn't like to go past.”

Rothman estimates this to be 310 gigatons. He thinks that given the rise of carbon dioxide over the last century, a sixth mass extinction could be on the way as estimates suggest that humans will add roughly 310 gigatons to the cycle by 2100.

READ MORE: ‘What the frack! We’re destroying all life, we have a huge problem’

“This is not saying that disaster occurs the next day,” Rothman said. “It’s saying that, if left unchecked, the carbon cycle would move into a realm which would be no longer stable, and would behave in a way that would be difficult to predict. In the geologic past, this type of behavior is associated with mass extinction.”

Rothman's paper was published Wednesday in the journal Science Advances.

What makes alcoholics drink? Research shows it's more complex than supposed

What makes alcoholics drink? New research has found that in both men and women with alcohol dependence, the major factor predicting the amount of drinking seems to be a question of immediate mood. They found that suffering from long-term mental health problems did not affect alcohol consumption, with one important exception: men with a history of depression had a different drinking pattern than men without a history of depression; surprisingly those men were drinking less often than men who were not depressed

"This work once again shows that alcoholism is not a one-size-fits-all condition," said lead researcher, Victor Karpyak (Mayo Clinic, MN, USA). "So the answer to the question of why alcoholics drink is probably that there is no single answer; this will probably have implications for how we diagnose and treat alcoholism."

The work, presented at the ECNP congress by researchers from the Mayo Clinic*, determined the alcohol consumption of 287 males and 156 females with alcohol dependence over the previous 90 days, using the accepted Time Line Follow Back method and standardized diagnostic assessment for life time presence of psychiatric disorders (PRISM); they were then able to associate this with whether the drinking coincided with a positive or negative emotional state (feeling "up" or "down"), and whether the individual had a history of anxiety, depression (MDD) or substance abuse.

The results showed that alcohol dependent men tended to drink more alcohol per day than alcohol dependent women. As expected, alcohol consumption in both men and women was associated with feeling either up or down on a particular day, with no significant association with anxiety or substance use disorders. However, men with a history of major depressive disorder had fewer drinking days (p=0.0084), and fewer heavy drinking days (p=0.0214) than men who never a major depressive disorder.

Victor Karpyak continued: "Research indicates that many people drink to enhance pleasant feelings, while other people drink to suppress negative moods, such as depression or anxiety. However, previous studies did not differentiate between state-dependent mood changes and the presence of clinically diagnosed anxiety or depressive disorders. The lack of such differentiation was likely among the reasons for controversial findings about the usefulness of antidepressants in treatment of alcoholics with comorbid depression.

This work will need to be replicated and confirmed, but from what we see here, it means that the reasons why alcoholics drink depend on their background as well as the immediate circumstances. There is no single reason. And this means that there is probably no single treatment, so we will have to refine our diagnostic methods and tailor treatment to the individual. It also means that our treatment approach may differ depending on targeting different aspects of alcoholism (craving or consumption) and the alcoholic patient (i.e. man or a woman) with or without depression or anxiety history to allow really effective treatment."

Commenting, Professor Wim van den Brink (Professor of Psychiatry and Addiction at the Academic Medical Centre, University of Amsterdam) said:

"This is indeed a very important issue. Patients with an alcohol use disorder often show a history of other disorders, including mood and anxiety disorders, they also often present with alcohol induced anxiety and mood disorders and finally the may report mood symptoms that do not meet criteria for a mood or anxiety disorder (due to a failure to meet the minimal number of criteria or a duration of less than two weeks). All these different conditions may influence current levels or patterns of drinking.

The current study seems to show that the current presence of mood/anxiety symptoms is associated with more drinking in both male and female alcoholics, whereas a clinical history of major depression in male alcoholics is associated with lower current dinking levels. Although, the study does not provide a clear reason for this difference, it may have consequences for treatment. For example, antidepressant treatment of males with a history major depression may have no effect on drinking levels. However, these findings may also result from residual confounding, e.g. patients with a history of major depression might also be patients with a late age of onset of their alcohol use disorder and this type of alcohol use disorder is associated with a different pattern of drinking with more daily drinking and less heavy drinking days and less binging. More prospective studies are needed to resolve this important but complex clinical issue."

*This work was presented on Sunday 3rd September, 2017.

Dinosaur asteroid hit 'worst possible place'

Scientists who drilled into the impact crater associated with the demise of the dinosaurs summarise their findings so far in a BBC Two documentary on Monday.

The researchers recovered rocks from under the Gulf of Mexico that were hit by an asteroid 66 million years ago.

The nature of this material records the details of the event.

It is becoming clear that the 15km-wide asteroid could not have hit a worse place on Earth.

https://ichef.bbci.co.uk/news/624/cpsprodpb/CA49/production/_96058715_bm_bm_eotd_02738308.jpgThe drill rig was on station in the Gulf in April and May last year / BARCROFT PRODUCTIONS/BBC

The shallow sea covering the target site meant colossal volumes of sulphur (from the mineral gypsum) were injected into the atmosphere, extending the "global winter" period that followed the immediate firestorm.

Had the asteroid struck a different location, the outcome might have been very different.

"This is where we get to the great irony of the story – because in the end it wasn’t the size of the asteroid, the scale of blast, or even its global reach that made dinosaurs extinct – it was where the impact happened," said Ben Garrod, who presents The Day The Dinosaurs Died with Alice Roberts.

https://ichef-1.bbci.co.uk/news/624/cpsprodpb/5901/production/_96058722_bm_bm_eotd_02738320.jpgThe fractured rocks were subjected to immense pressures / BARCROFT PRODUCTIONS/BBC

"Had the asteroid struck a few moments earlier or later, rather than hitting shallow coastal waters it might have hit deep ocean.

"An impact in the nearby Atlantic or Pacific oceans would have meant much less vaporised rock – including the deadly gypsum. The cloud would have been less dense and sunlight could still have reached the planet’s surface, meaning what happened next might have been avoided.

"In this cold, dark world food ran out of the oceans within a week and shortly after on land. With nothing to eat anywhere on the planet, the mighty dinosaurs stood little chance of survival."

Ben Garrod spent time on the drill rig that was stationed 30km off Mexico's Yucatan Peninsula in April/May last year, to better understand the aims of the project; Alice Roberts visited widely separated fossil beds in the Americas, to get a sense of how life was upended by the impact.

Rock cores from up to 1,300m beneath the Gulf were recovered.

The lowest sections of this material come from a feature within the crater called the peak ring.

This is made from rock that has been heavily fractured and altered by immense pressures.

By analysing its properties, the drill project team - led by Profs Jo Morgan and Sean Gulick - hope to reconstruct how the impact proceeded and the environmental changes it brought about.

Chicxulub Crater - The impact that changed life on Earth

  • A 15km-wide object dug a hole in Earth's crust 100km across and 30km deep
  • This bowl then collapsed, leaving a crater 200km across and a few km deep
  • The crater's centre rebounded and collapsed again, producing an inner ring
  • Today, much of the crater is buried offshore, under 600m of sediments
  • On land, it is covered by limestone, but its rim is traced by an arc of sinkholes
  • They know now the energy that went into making the crater when the asteroid struck - equivalent to 10 billion Hiroshima A-bombs. And they also understand how the depression assumed the structure we observe today.

    The team is also gaining insights into the return of life to the impact site in the years after the event.

    One of the many fascinating sequences in the BBC Two programme sees Alice Roberts visit a quarry in New Jersey, US, where 25,000 fossil fragments have been recovered - evidence of a mass die-off of creatures that may have been among the casualties on the day of the impact itself.

    "All these fossils occur in a layer no more than 10cm thick," palaeontologist Ken Lacovara tells Alice.

    "They died suddenly and were buried quickly. It tells us this is a moment in geological time. That's days, weeks, maybe months. But this is not thousands of years; it's not hundreds of thousands of years. This is essentially an instantaneous event."

    The Day The Dinosaurs Died is on BBC Two at 21:00, after which it will be available on the BBC iPlayer.

Full Moon, Comet Starring in Night Sky Show This Weekend

A full moon and comet share double billing in a special night sky show this weekend.

A lunar eclipse starts everything off Friday night. The moon will pass into Earth's outer shadow, or penumbra. The moon won't be blacked out like in a full eclipse. Only part of the moon will be shaded, but it should be easily visible from much of the world.

Comet 45P, meanwhile, will zoom past Earth early Saturday morning. It will be an extremely close encounter as these things go, passing within 7.7 million miles (12.4 million kilometers) of Earth. Its relative speed: 14.2 miles per second, or a breakneck 51,120 mph.

The comet, glowing green, will be visible in the constellation Hercules. Binoculars and telescopes will help in the search.

Stargazers have been tracking Comet 45P for the past couple of months. The ice ball — an estimated mile across — comes around every five years. It's officially known as Comet 45P/Honda-Mrkos-Pajdusakova, named after the Japanese, Czech and Slovak astronomers who discovered it in 1948. The letter P stands for periodic, meaning it's a recurring visitor to the inner solar system.

The Slooh network of observatories will provide a live broadcast from the Canary Islands for both big events.

The eclipse will last more than four hours, beginning at 5:32 p.m. EST. The action will unfold early Saturday in Europe, Africa and western Asia.

Early Mars didn’t have enough CO2 to keep water liquid, Curiosity finds

Liquid water on Mars' surface, but not enough CO2 above to keep it there.

Even though Mars is currently too cold and has too little pressure to prevent water from freezing, the planet had liquid water on its surface in the distant past. That could happen if the ancient Martian atmosphere, thicker than its present-day counterpart, had enough greenhouse gasses to keep the planet warm and the water liquid. So over the past decades of our observations and robotic visitations of Mars, researchers have been looking for evidence for Mars' past carbon dioxide levels.

The evidence we've gathered indicates there was some CO2 present but not nearly enough to keep water liquid, especially given that the early Sun was less active than it is at present. So far, these estimates contained large uncertainties, so it remained possible that there was enough carbon in the atmosphere to allow the ancient water to flow.

A team of researchers has created a new estimate of Mars' ancient carbon levels using data collected by the Curiosity rover. They've also concluded that there was nowhere near enough CO2 to warm the planet to the point where water on the surface would remain liquid.

https://cdn.arstechnica.net/wp-content/uploads/2013/07/MSL-self-portrait-pia16239-20121101-300x417.jpgEnlarge / A "selfie" taken by Curiosity (actually assembled from a mosaic of selfies). The rover captured the public's imagination with its daring, Rube Goldberg-ian skycrane touchdown on Mars.

During its trip towards Aeolis Mons (the peak at the center of the Gale crater), Curiosity came upon what looked to be the remains of an ancient lake. This was a region of about 70 meters with mudstones, siltstones, and sandstones left behind by ancient water, somewhere between 3.8 and 3.1 billion years ago. The rover analyzed these materials as it passed, but there were no carbonate minerals, which would have made assessing past carbon levels easier. However, certain clays could provide a way to estimate the ancient carbon concentration.

When these clays formed, CO2 would have dissolved into their structure. While we can't measure them, we can infer their presence indirectly, as dissolved carbon limits the solubility of iron-bearing olivine. The amount of this olivine in the clays puts a limit on the amount of CO2 that could be in the water that the clays formed in.

This technique is also used to estimate Earth’s early atmosphere, but here it’s actually less reliable because the presence of life contaminates the process. The Martian rocks have been comparatively undisturbed, making them prime targets for science. “In many ways, deriving [CO2] estimates from Gale Crater sedimentary rocks is more straightforward than doing so in their terrestrial equivalents,” the authors write in their paper.

The researchers made a detailed analysis of the compounds involved in the clays, comparing them to those found in thousands of lakebeds on Earth. The time it takes for various chemicals to mix in with the clays is an important factor as well, as it affects how much of them we’d observe now.

The researchers conclude that the Martian atmosphere at the time the clays were formed had a lot more CO2 than the lower limits of previous estimates. But the numbers are still fall far short of what's needed to keep the temperature above freezing.

This doesn't definitively rule out the greenhouse explanation; certain environmental processes the researchers are not considering could have changed the composition of the clays. Where does that leave things? It's largely the same predicament as before. This study adds more evidence that Mars didn’t have enough CO2 in its atmosphere to have kept water liquid from 3.8 to 3.1 billion years ago. So either warming was driven by some other mechanism, or somehow the water was able to flow despite temperatures that were typically below. Either conclusion would be interesting.

The data also provides more information about a critical period in the history of Mars—around the time these clays were formed, Mars was rapidly losing its atmosphere. This site is among the youngest of the now-dry sites of surface water yet discovered, meaning these clays were probably formed during the tail end of this process. Those were essentially the last days of the wet Mars.

Subscribe to this RSS feed