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Limiting warming to 1.5° Celsius rather than 2.0° Celsius would maintain significant proportions of systems such as Arctic summer sea ice, forests and coral reefs and have clear benefits for human health and economies, say Ove Hoegh-Guldberg and colleagues in this Review. Their Review expands upon a 2018 special report by the Intergovernmental Panel on Climate Change focused on the effects associated with climate warming to 1.5° Celsius (C) above pre-industrial levels. Hoegh-Guldberg et al. overview a range of scientific approaches that have been used for understanding how the world may change at 1.5°C versus 2.0°C of global warming, all of which show qualitatively consistent results regarding how mean weather extremes would increase in the latter scenario. For example, very intense cyclones are likely to occur more frequently at 2.0°C vs 1.5°C of global warming, they say, with associated increases in heavy rainfall and damage. The authors say that achieving the 1.5°C target requires immediate and transformative actions in the next decade, and even as it would be costly, the benefits would still greatly outweigh the toll likely to be exacted due to inaction. "Aiming to limit warming to 1.5° Celsius is now a human imperative if escalating risks of dangerous if not catastrophic tipping points and climate change hotspots are to be avoided," the authors say.

The New York Times makes a concerted effort to drive home the point that climate change is real, but it does a poor job of presenting the basic facts about climate change that could convince skeptics, according to a review of the paper's coverage since 1980.

Public polls show that Americans, whether agreeing or disagreeing with the idea that human activity is changing Earth's climate, lack an understanding of the basic facts leading to this conclusion, says climate scientist David Romps, a University of California, Berkeley, professor of earth and planetary science. A large percentage of the public doesn't know that global warming is happening now, that it's caused by record levels of CO2 from fossil fuel burning, that 99% of climate scientists agree on this and that the changes are effectively permanent.

"If The New York Times isn't doing it, my guess is that it is just not happening across print journalism," Romps said. "One of the hopes is that, by at least pointing this out, it might occur to people to take a look at what kind of context is provided in news coverage of climate change."

Romps and co-author Jean Retzinger, the former associate director of UC Berkeley's Media Studies program, published their analysis in the journal Environmental Research Communications.

After more than a decade of research focused on how climate change affects the atmosphere -- in particular, clouds and lightning -- Romps became frustrated about the public's lack of basic knowledge of the science that underlies the 99% consensus among climate scientists.

"The notion that there is a scientific consensus has been referred to as a gateway belief by people who study how the public thinks about climate change," Romps said. "They find that, if you can get people to understand that fact, it kind of pries the door open and makes them open to learning more and potentially changing their minds."

Yet, as of 2019, the fact of a scientific consensus is mentioned in a mere 4% of Times articles about climate change, he and Retzinger found. The fact that we are experiencing levels of carbon dioxide in the atmosphere that haven't been seen in millions of years -- and never before in human history -- is mentioned in only 1% of the paper's articles.

And the fact that climate change is permanent is mentioned in only 0.4% of articles.

"We are talking about an alteration of the planet's climate, and in all of my conversations with people, no one has ever asked me how long it lasts," Romps said. "I don't understand how people can have any sort of opinion about global warming without knowing that fact: that it is effectively permanent. The time scale for drawing the CO2 anomaly back down to where it was 50 years ago is on the order of 100,000 years, 10 times longer than human civilization. So it is, for all intents and purposes, permanent. And each additional increment of warming is effectively permanent."

Lack of facts sows confusion

A fourth climate-change fact he looked at -- that CO2 produced by fossil fuel burning creates a greenhouse effect that warms the planet -- was mentioned in only 0.1% of the articles. Many people confuse the effects of carbon dioxide with the ozone hole, which is caused by chlorofluorocarbons used in refrigerators, or think that warming is due to the heat produced by burning oil and gas.

His data show that, in the 1980s, when the concept of global warming was still new to many readers, the Times often referred to the mechanism of greenhouse warming and did so, in some years, in every article. But 20 years later, this mechanism is seldom mentioned, despite a whole new generation of readers.

The only fact mentioned regularly -- in nearly one-third of all articles -- is that the effects of climate change are being felt now. But of the 600 news articles mentioning climate change over the 38-year period, the vast majority contained none of the five basic climate facts. This occurred despite the ease with which the basic facts of climate science were embedded in articles that did mention these facts.

"We have this major problem: that people don't seem to have a solid grasp of the fundamental ideas. And why would that be?" he asked. "There has been a well-funded campaign to spread misinformation and sow doubt about global warming, which has been very successful. On the other hand, climate scientists are not necessarily out there communicating effectively to the public."

"After you finish school, you learn about science primarily through the news," he added. "And if you are not getting appropriate context from that news coverage, you are going to be confused."

Romps is embarking on an experiment to try to change this, partnering with UC Berkeley's Graduate School of Journalism to offer fellowships to student environmental writers to discuss with climate scientists the basic facts about climate change and how best to convey them within news articles. If this proves effective in changing public understanding, it could open the door to a broader national discussion of climate change coverage in the media.

Paper of record

To assess whether the basic facts behind the scientific consensus about climate change are being communicated through the media, Romps and Retzinger focused on perhaps the number one paper of record in the nation, the Times.

"We chose The New York Times because it certainly has this reputation of being excellent in covering environmental issues and climate change, and I personally think it's one of the best," he said. "At the same time, I had this feeling from having read stories on climate that they didn't convey the basic facts to readers, and that that might be a problem."

They enlisted the help of a dozen undergraduate students to review New York Times articles mentioning climate change that were published between 1980 and 2018, in search of the key words employed when mentioning five basic facts: the consensus, mechanism, longevity, magnitude and immediacy of climate change.

They then searched for all articles that included these key words, and Romps read each one to judge whether or not it mentioned these five facts.

"I don't think that everyone learning the basic facts I have outlined here is a solution in itself. But I do believe it is a necessary condition," he said. "We are not going to make the progress we need until everyone from both political parties, from rural and urban areas, from all states, accept the fact that global warming is happening, it is caused by us, and that the solution is to stop burning fossil fuels. These are the basic facts that climate scientists know, policy wonks know, but somehow the broader public does not quite appreciate yet."

In addition to his efforts to better communicate the facts of climate change, Romps hopes to set an example for those wanting to reduce their carbon footprint. Last year, he refused to fly to an awards presentation, and since January has not flown to any scientific meetings -- a big drop from his typical yearly air mileage topping 100,000 miles. He'd like to deliver scientific papers to colleagues via video streaming, but this is not yet an accepted practice at annual meetings.

Nevertheless, he is heartened by younger people speaking out, and he supports the Sept. 20 worldwide climate strike, including a UC Berkeley rally at 11 a.m. in Sproul Plaza with talks by students and faculty. While Romps that day will be teaching his undergraduate course on the science of climate change, he plans to attend the rally and encourages his students to do the same.

"Being a climate scientist can be a fairly depressing occupation," Romps said. "But seeing young people stand up and make their voices heard is really quite encouraging. There is hope. The youth have been heeding the call, and we need grown-ups to start heeding the call, too."

Imagery from NASA-NOAA's Suomi NPP satellite found Tropical Storm Lorena lashing the western coast of Mexico.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Lorena on Sept. 18 that revealed powerful storms circled the low-level center. The image showed strong bands of thunderstorms sweeping over the coast of western Mexico over the western parts of Michoacan and Colima states. Data from NASA's Aqua satellite revealed that some of the thunderstorms were over 12,000 meters or 7.4 miles high. NASA research has shown storms high in the troposphere can be strong storms that generate heavy rainfall. It was that heavy rainfall that continued to drench the western coast of Mexico.

Microwave and satellite imagery indicated that the center of Lorena moved along the southwestern coast of Mexico overnight and during the morning of Sept. 19.

Lorena did not move much from the coast since the Suomi NPP satellite image was captured. NOAA's National Hurricane Center or NHC said, at 11 a.m. EDT (1500 UTC) on Sept. 19 the center of Lorena moved offshore just west of Cabo Corrientes and heavy rains and strong winds continue along the southwestern coast of Mexico.

Coastal sections of the Mexican states of Michoacan, Colima and Jalisco will get 5 to 10 inches with maximum amounts of 15 inches. This rainfall may produce life threatening flash floods and mudslides. Far southern Baja California Sur will get 2 to 4 inches with maximum amounts around 6 inches.

A Hurricane Watch is in effect for Baja California peninsula from La Paz to Santa Fe and a Tropical Storm Warning is in effect for Manzanillo to Punta Mita and for the Baja California peninsula from Los Barriles to Todos Santos.

The center of Tropical Storm Lorena was located near latitude 20.5 North, longitude 105.9 West. Lorena is moving toward the northwest near 10 mph (17 km/h). A turn to the west-northwest is expected tonight, and a west-northwestward motion at a slow forward speed should continue Saturday [Sept. 21]. Maximum sustained winds are near 70 mph (110 kph) with higher gusts. Strengthening is forecast during the next day or so, and Lorena is forecast to regain hurricane strength later today or tonight. The estimated minimum central pressure is 994 millibars.

On the forecast track, the center of Lorena will move over the Pacific waters to the southeast of the Baja California peninsula today and tonight, and then pass near or just south of the southern tip of the Baja California peninsula late Friday and Friday night.

One research group comprising Brazilian and Japanese scientists have discovered how luciferase produced by the railroad worm Phrixothrix hirtus emits red light.

Luciferase is an enzyme that catalyzes the oxidation of luciferin in fireflies, producing oxyluciferin and enabling fireflies to emit light. Differences in the molecular structures explain the different colors of this bioluminescence in different species.

This discovery has the potential for new biotechnological applications, such as the imaging of muscles, blood and hemoglobin-rich tissue.

An article published in Scientific Reports describes the study, which was conducted by researchers at the Federal University of São Carlos (UFSCar) in São Paulo State, the National Bioscience Laboratory (LNBio) attached to Brazil's National Energy and Materials Research Center (CNPEM), and the University of Electro-Communications in Tokyo, Japan.

The Brazilian team used cloned railroad worm luciferase, which naturally emits red light and mutants of the enzyme together with a larger analog of luciferin synthesized by the Japanese team.

"This novel combination of luciferase with a luciferin analog not only revealed the larger size of the cavity in the luciferase but also produced far-red light more efficiently and is ideal for biomedical applications involving imaging of cells and tissues that preferably absorb blue-green light, such as mammalian cells," Vadim Viviani, a professor at UFSCar (Sorocaba campus) and principal investigator for the study, told.

In a previous study, the group led by Viviani showed that luciferase from fireflies, which are close relatives of railroad worms, changed the color of the light they emitted from green to red in a test tube in response to a change in the acidity of the medium or the presence of heavy metals (read more at: revistapesquisa.fapesp.br/en/2019/06/24/green-yellow-or-red/).

The group did not yet know how red light was produced naturally by railroad worm luciferase, however, and has now shown how the phenomenon occurs in this species of beetle. Vanessa Rezende Bevilaqua, the first author of the article, participated in the research for her PhD with São Paulo Research Foundation - FAPESP's support.

The study was also part of the FAPESP Thematic Project Arthropod bioluminescence.

P. hirtus is native to the Americas and is one of the few animals known to emit red light as well as green-yellow light, which is more common. During the larval stage, P. hirtus has several green "lanterns" on its back and a red one on its head. The latter helps the beetle find its way in the dark. The light sources on its back serve to frighten predators.

When males of the species become adults, they lose the red lantern but keep the two green ones. Adult females keep them all.

"We've now shown that yellow-green luciferases have a smaller cavity at the active site where luciferin binds and is oxidized to oxyluciferin," Viviani said. "The luciferin is compressed into a more rigid environment, leading to electrostatic repulsion between the two molecules [the energized oxyluciferin and the walls of the luciferase active site], releasing light that contains more energy and is therefore green or yellow."

In the case of the red luciferase produced by the head, the active site cavity is larger, there are more water molecules present, and the environment is less rigid, leading to a reduction in the electrostatic repulsion between the luciferin and the walls of the luciferase active site. This is why the light emitted is red, which contains less energy.

Bioimaging

To investigate the interactions that lead to the emission of red light, researchers have learned over the past few decades to clone various luciferases by using genetic engineering tools to modify some amino acids.

The Japanese group, led by Takashi Hirano at the University of Electro-Communications, synthesized red light-emitting luciferin analogs, which were tested by Bevilaqua with the firefly and railroad worm luciferases cloned and modified by the Brazilian research group.

Some of these modified luciferins had a larger structure than the others, and these larger luciferins interacted best with railroad worm luciferase, emitting far-red light more efficiently, whereas they did not interact efficiently with the green or yellow luciferases.

"The luciferases that catalyze green and yellow light have a small cavity and therefore don't bind well to the large-structure luciferin analogs, which have very little luminescent activity," Viviani said. "On the other hand, these large analogs interact well with luciferases that catalyze red light. We deduced from this that railroad worm luciferase has a large active site cavity capable of binding to the analogs."

Having achieved this result, the researchers began testing new combinations of luciferins with modified railroad worm luciferase, eventually creating a more intense red light than that produced by P. hirtus. They believe that the combinations could be used in biomedical research.

"The luciferin analogs synthesized by the Japanese group aren't the first to be created but offer the advantage of having more luminescent activity and a red-shifted light spectrum when they're combined specifically with luciferase from P. hirtus. The commercially available analogs are less efficient, albeit more red-shifted," Viviani said.

Initially, the idea is that this discovery could be used to enhance the visualization of biochemical and cellular processes in mammalian substances that do not absorb red light, such as blood cells and muscle tissue.

"When these substances are examined with conventional luciferase that emits green, yellow or blue light, it's impossible to see biochemical and pathological processes clearly because pigments such as hemoglobin and myoglobin absorb most of the light in these parts of the chromatic spectrum," Viviani said.

ITHACA, N.Y. - A team of scientists has developed a computational model that uses artificial intelligence to find sites for hydropower dams in order to help reduce greenhouse gas emissions.

Hydropower dams can provide large quantities of energy with carbon footprints as low as sources like solar and wind. But because of how they're formed, some dams emit dangerously high levels of greenhouse gases, threatening sustainability goals.

With hundreds of hydropower dams currently proposed for the Amazon basin - an ecologically sensitive area covering more than a third of South America - predicting their greenhouse emissions in advance could be critical for the region, and the planet.

The Cornell University-led team of ecologists, computer scientists and researchers from South American organizations found that achieving low-carbon hydropower requires planning that considers the entire Amazon basin - and favors dams at higher elevations.

"If you develop these dams one at a time without planning strategically - which is how they're usually developed - there is a very low chance that you'll end up with an optimal solution," said Rafael Almeida, postdoctoral research fellow with the Atkinson Center for a Sustainable Future and co-lead of "Reducing Greenhouse Gas Emissions of Amazon Hydropower with Strategic Dam Planning," which published Sept. 19 in Nature Communications.

Using the model, the researchers can identify the combination of dams that would produce the lowest amounts of greenhouse gases for a given energy output target.

When areas are flooded to build dams, decomposing plant matter produces methane, a more destructive greenhouse gas than carbon dioxide. Depending on the location and other factors, the carbon emissions from dam construction can vary from lowest to highest by more than two orders of magnitude.

The analysis found that dams built at high elevations tend to lower greenhouse gas emissions per unit of power output than dams in the lowlands - partly because less land needs to be flooded in steeper environments.

There are currently around 150 hydropower dams and another 350 proposed for the Amazon basin, which encompasses parts of Brazil, Ecuador, Peru and Bolivia. This study is part of a larger effort to use computational tools to analyze the dams' impact to help South American governments and organizations make informed decisions that balance the benefits and disadvantages.

Many people in the U.S. do not belong to Native American communities but still carry bits of Native American DNA, inherited from European and African ancestors who had children with indigenous individuals during colonization and settlement. In a new study published 19th September in PLOS Genetics, Andrew Conley of the Georgia Institute of Technology and colleagues investigate this genetic legacy and what it can tell us about how non-natives migrated across the U.S.

When Europeans colonized North America, infectious diseases and violent conflict greatly reduced the numbers of Native Americans living on the continent. Their DNA lives on, however, not only in recognized Native American tribes, but also in the descendants of Europeans and enslaved Africans that settled within the country. To better understand this genetic reservoir, researchers analyzed patterns of Native American ancestry from genomic data collected from descendants of African slaves, and Spanish and Western European settlers.

The analysis showed that African descendants had low levels of Native American ancestry, consistent with the two groups mixing in the Antebellum South, followed by African American dispersal in the Great Migration. European descendants had the lowest amount of Native American ancestry, and showed a historical pattern of continual but infrequent mixing between local Native American groups and European settlers as they moved westward. Spanish descendants had the highest and most variable amounts of Native American ancestry, and their profiles showed regional patterns reflecting the different waves of Spanish-descended immigrants that moved into the country. Native American DNA was sufficient to distinguish between descendants of very early Spanish settlers in the U.S., known as Hispanos or Nuevomexicanos, and descendants of subsequent immigrants arriving from Mexico.

"The presence of Native American genetic ancestry among individuals who do not self-identify as Native American can also be leveraged to broaden genomic medicine and include population groups currently underserved and underrepresented in genomic databases," said author Andrew Conley. "For future studies, we are very interested to use this rich genomic resource to study the distribution of health-related genetic variants in the Native American genomic background."

Overall, the study shows that much of the genetic legacy of the original inhabitants of the area that is now the continental U.S. can be found in the genomes of the descendants of European and African immigrants to the region. By making use of large genomic databases, the new study adds insight into the current discussion of the meaning of Native American identity and its distinction from genetic ancestry.

NASA-NOAA's Suomi NPP satellite imagery revealed Tropical Storm Mario appeared to be losing its rounded shape in the Eastern Pacific Ocean.

When tropical cyclones begin to lose their shape and appear less circular, it is generally an indication of a storm that is weakening. Circular storms can spin faster, just like a tire on a car. Once the tire loses its circular shape it can't rotate as fast.

The Visible Infrared Imaging Radiometer Suite (VIIRS) instrument aboard Suomi NPP provided a visible image of Mario on Sept. 18 at 5:36 p.m. EDT (2136 UTC) that indicated wind shear was affecting the storm as it did not appear circular as a result of wind shear. NPP data is used by forecasters at NOAA's National Hurricane Center to assess factors of the storm that include structure and strength.

NASA's Aqua satellite also passed over Mario and provided cloud top temperature data. Aqua showed Mario contained some powerful thunderstorms stretching high into the troposphere with cloud top temperatures as cold as or colder than 220 Kelvin (minus 63 degrees Fahrenheit / minus 53 degrees Celsius). NASA research has shown that storms with cloud top temperatures that cold can produce heavy rainfall.

NHC forecasters also utilized data to determine moderate easterly wind shear, associated at least in part with outflow from Mario's larger sibling (Lorena) to the east, has prevented the tropical storm from strengthening at a faster rate.

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels.

During the morning of Sept. 19, microwave and first-light visible imagery suggest that the low-level center of Mario may be displaced to the east of most of its strongest thunderstorms, indicating a weakening storm.

NOAA's National Hurricane Center or NHC said, "At 11 a.m. EDT (1500 UTC), the center of Tropical Storm Mario was located near latitude 16.5 degrees north and longitude 111.5  degrees west. Mario is moving toward the north near 7 mph (11 kph). Maximum sustained winds are near 65 mph (100 kph) with higher gusts.  Little change in strength is forecast during the next several days.

Mario is currently embedded within low- to mid-layer southwesterly flow and this should cause the cyclone to move generally northeastward or north-northeastward for the next day or two. What happens after that depends largely on Lorena.

When a series of large mammal species began going extinct roughly 12,000 years ago, many surviving species began going their separate ways, says new research led by Macquarie University and the University of Nebraska-Lincoln.

Published Sept. 20 in the journal Science, the study analyzed distributions of mammal fossils across North America following the last ice age, after the retreat of massive glaciers that had encroached south to the modern-day United States. The aftermath saw the disappearance of many famously large mammal species: mammoths, mastodons, saber-toothed cats, dire wolves and ground sloths, among others.

Surviving mammal species often responded by distancing themselves from their neighbors, the study found, potentially reducing how often they interacted as predators and prey, territorial competitors or scavengers.

The ecological repercussions of the extinctions are likely still echoing today and could preview the effects of future extinctions, said study co-author Kate Lyons.

"For 300 million years, the (cohabitation) pattern of plants and animals looked one way -- and then it changed in the last 10,000 years," said Lyons, assistant professor of biological sciences at Nebraska. "This paper addresses how that happened in mammal communities.

"If connectedness among species makes ecosystems more stable, what this suggests is that we've already lost a lot of those links. What this potentially tells us is that modern ecosystems are probably more vulnerable than we think they are."

Led by Macquarie's Anikó Tóth, the team analyzed records of 93 mammal species at hundreds of fossil sites during three timespans: 21,000 to 11,700 years ago, when the extinctions began; 11,700 to 2,000 years ago; and 2,000 years ago to the present. The researchers then assessed whether, and to what extent, a given species lived among each of the other 92 at those sites.

That data allowed the team to calculate how often a random pair of species would be expected to cohabit a site, providing a baseline for whether each pair overlapped more or less often than predicted by chance -- aggregating vs. segregating, respectively. The proportion of aggregating pairs generally declined following the extinctions, and the strength of associations often dropped even among species that continued to aggregate, the researchers found.

"The loss of the giant carnivores and herbivores changed how small mammals such as deer, coyotes and raccoons interacted," Tóth said. "Our work suggests that these changes were triggered by the ecological upheaval of the extinctions."

Tóth, Lyons and their 17 co-authors effectively ruled out climate change and geography as drivers of the growing division. Surprisingly, the team also concluded that surviving species began cohabiting less frequently even as they expanded into larger swaths of their respective geographic ranges.

Lyons said the specific reasons for the seeming paradox and the overall trends are unclear, though the ecological consequences of losing species such as the mammoth could explain them. Mammoths toppled trees, compacted soil and, by eating and excreting masses of vegetation, transported nutrients around ecosystems, Lyons said. Those behaviors helped sustain the so-called mammoth steppe, an ecosystem type that once covered vast areas of the Northern Hemisphere. The loss of the mammoth effectively doomed the mammoth steppe, possibly compartmentalizing the expanses of land that hosted many species.

"If you're an open-habitat species that used to occupy the mammoth steppe, and now the mammoth steppe has gone away, you might inhabit, say, open grassland areas that are surrounded by forests," Lyons said. "But that meadow is much smaller. Instead of supporting 10 species, it now might support five. And if those patches of open habitat are spread farther apart, you might expand your geographic range and potentially your climate range, but you would co-occur with fewer species."

Also uncertain: why common species became more common, and some rare species became even rarer, following the extinctions. Continuing to study the dynamics underlying such trends could help sharpen perspectives on current ecosystems and their possible fates, the researchers said.

"We had a complement of large mammals in North America that was probably more diverse than what we see in Africa today," Lyons said. "Additional extinctions could have a cascading effect and huge implications for the mammal communities that we have left."

World leaders need to urgently accelerate efforts to prevent "profound, if not catastrophic" climate change in future, a distinguished group of scientists has warned.

According to their new study published in Science today, acting to reduce climate change would cost much less than repairing the damage it would inflict in coming decades on people, infrastructure and ecosystems.

Lead author and Australian Research Council Centre for Excellence in Coral Reef Studies Deputy Director Professor Ove Hoegh-Guldberg said acting on climate change has a good return on investment when the damages avoided by taking action are taken into consideration.

"That investment is even more compelling given the wealth of evidence that the impacts of climate change are happening faster and more extensively than projected even just a few years ago," Professor Hoegh-Guldberg said.

"This makes the case for rapidly reducing greenhouse gas emissions more urgent."

Professor Hoegh-Guldberg said the science community had underestimated the sensitivity of natural and human systems to climate change, and the speed at which the changes were happening.

"We have also underappreciated the synergistic nature of climate threats - with the outcomes tending to be worse than the sum of the parts," he said.

"This is bringing rapid and comprehensive climate impacts, with growing damage to people, their livelihoods and ecosystems."

Professor Hoegh-Guldberg said sea-level rise could lead to higher water levels during storms.

"This can create more damage, and for deprived areas, this may exacerbate poverty - creating further disadvantage," he said.

"Each risk may be small, but small changes in a number of risks can lead to large impacts."

The paper updates a database of climate-related changes and reports there will be significant benefits from keeping global temperatures within 1.5oC above pre-industrial global temperatures.

Professor Hoegh-Guldberg said 2020 would be a vital year for climate action and for seizing the opportunity to reduce emissions in line with the 2015 Paris Agreement.

"Current emission reduction commitments are inadequate and risk throwing many nations into chaos and harm, with a particular vulnerability of poor peoples," Professor Hoegh-Guldberg said.

"To avoid this, we must accelerate action and tighten emission reduction targets so they fall in line with the Paris Agreement.

"Our paper shows this is much less costly than suffering the impacts of 2oC or more of climate change.

"Tackling climate change is a tall order. However, there is no alternative from the perspective of human well-being - and too much at stake not to act urgently on this issue."

NASA's Aqua Satellite provided data on Major Hurricane Humberto that revealed its structure was changing as it was moving through the North Atlantic Ocean and past Bermuda.
On Sept. 18 at 12:30 p.m. EDT, the Moderate Imaging Spectroradiometer or MODIS instrument that flies aboard NASA's Aqua satellite provided visible data on Humberto and measured clouds heights and temperatures that indicated a shift in the storm.

The visible image revealed powerful thunderstorms circled the center and a large band stretched hundreds of miles east. Additional data showed the highest cloud tops, higher than 12,000 meters (7.65 miles) were located mostly south and southwest of the eye, although a small area circled the eye. Those were the most powerful storms within Humberto. Aqua research data also found that cloud top temperatures were as cold as or colder than 200 Kelvin (minus 99.6 degrees Fahrenheit/minus 73.1 degrees Celsius) around in those storms. NASA research has shown that cloud top temperatures that cold have the capability to generate heavy rainfall.

The cloud height and temperature data was provided by NASA's Worldview product at NASA's Goddard Space Flight Center, Greenbelt, Md. Hurricanes are the most powerful weather event on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

Hours later, NOAA's National Hurricane Center or NHC noted at 5 p.m. EDT, "Humberto is taking on more of a hybrid-extratropical structure based on most of the rain shield having been displaced to the left or poleward side of the circulation now as seen in Bermuda weather radar data, and also in conventional and passive microwave satellite imagery."

On Sept. 19 at 5 a.m. EDT, NHC indicated that Humberto's extratropical transition continued and that large-scale models, as well as the Florida State University Cyclone Phase Evolution forecast, indicate that the process will be completed in less than 36 hours.

At 11 a.m. EDT (1500 UTC) on Sept. 19, the center of Hurricane Humberto was located near latitude 35.2 degrees north and longitude 62.2 degrees west. Humberto was about 250 miles (400 km) northeast of Bermuda. Humberto is moving toward the northeast near 22 mph (35 kph).  This general motion is expected to continue today, followed by a north-northeastward motion at a slower forward speed Thursday night and Friday. On the forecast track, the center of Humberto will continue to move away from Bermuda.

Maximum sustained winds are near 125 mph (205 kph) with higher gusts.  Humberto is a category 3 hurricane on the Saffir-Simpson Hurricane Wind Scale. Hurricane-force winds extend outward up to 90 miles (150 km) from the center and tropical-storm-force winds extend outward up to 405 miles (650 km). The estimated minimum central pressure is 952 millibars.

On Sept. 19, Humberto was stirring up the seas and creating hazardous conditions.

Large swells and dangerous surf generated by Humberto will continue along the coast of Bermuda through today, and these could continue to cause coastal flooding. Swells will continue to affect the northwestern Bahamas and the southeastern coast of the United States from east-central Florida to North Carolina during the next couple of days.

The hurricane should start to weaken today, and it is expected to become a post-tropical cyclone by Friday.

For updated forecasts, visit: http://www.nhc.noaa.gov

As a fighter jet quickly ascends and accelerates forward, a sonic boom reverberates across the jet's surface and through the surrounding sound waves. At best, it's unpleasant noise pollution. At worst, it can damage the surface of the aircraft. Dissipating this shock wave presents a tough challenge as traditional methods tend to offer efficiency or precision, but not both.

Now researchers with Yokohama National University in Japan have developed a unified shock sensor to quickly and accurately dispel harmful shock waves. They published their results on July 4 in the Journal of Computational Physics.

"There's a growing need for a simple and accurate shock-detection method in computational fluid dynamics," said Keiichi Kitamura, associate professor of engineering at the Yokohama National University in Japan. But scientists don't want to completely eliminate shocks - not all shocks are bad, after all. When applied correctly, a shock wave can flow through kidney stones and disintegrate the calcified rocks to make them easier for a person to pass. That process requires significantly more accuracy to avoid damaging healthy tissue, but it can be time consuming.

"Shock has been applied to the medical field through Extracorporeal Shock Wave Lithotripsy," Kitamura said. "It's one of the most common treatments for kidney stones in the United States of America. But most of the conventional shock-proofing methods are designed to satisfy only accuracy or efficiency."

"In all cases, it is of great importance to identify the exact location of the shock wave quickly," Kitamura said.

In the new study, researchers combined an imaging processing method with a theory on the expected conditions in compressible flow physics - when fluid flow has compressible effects, such as creating a shock wave when the fluid moves quicker than the speed of sound. This speed is what is responsible for shock.

The researchers altered the imaging processing method to look for pressure instead of discontinuous changes of brightness in digital images. This allows them to quickly see the shock wave. By combining the visualized image of the shock with the theory of how the pressure should jump across the shock, researchers can accurately predict how a specific shock wave will behave. The imaging process method is what Kitamura calls "computationally cheap," since it focuses on just the outlines of greatest pressure, rather than attempting to account for all the variable pressure in the image.

The researchers also compared their method to traditional sensors to test for efficiency and accuracy: the Kanamori-Suzuki sensor and the Ducros sensor. The Kanamori-Suzuki uses the theory of flow characteristics to sense shock and it is known for its accuracy. The Ducros is widely used and known for its inexpensive efficiency.

"In our examples, we confirmed that our method is as accurate at the Kanamori-Suzuki method and as cheap as the Ducros sensor," Kitamura said.

Currently, the method is limited to grids of square cells, which is what the imaging software uses. Next, the team plans to expand their method to apply to a wide array of differently structured grids. This could be applied to a variety of technologies, including improvements in how a jet dissipates shock.

"As this research advances, the shock capturing ability will become more efficient, leading to drastic cost reductions in developing aircraft vehicles and pursuing space developments," Kitamura said.

A protective protein that can detect newly-made incomplete and hence potentially toxic protein chains in higher cells is found to have a relative in bacteria. There, the protein also plays a central role in quality control which ensures that defective proteins are degraded. The functional mechanism of these evolutionarily related Rqc2 proteins thus acts as key quality control component and must therefore have already existed several billion years ago in the so-called last universal common ancestor. Scientists at the Center for Molecular Biology of Heidelberg University (ZMBH) have reached this conclusion based on their experimental study of the function of the bacterial Rqc2 relative.

In cells, incomplete protein chains originate regularly due to problems during their synthesis. Such aberrant chains are potentially toxic to cells and must be eliminated. In cells of eukaryotic organisms - such as fungi, plants and animals - a quality control process, known as Ribosome-associated Quality Control (RQC), leads to the disposal of those defective proteins.

A key component of RQC is the Rqc2 protein, which is responsible for sensing the aberrant protein chains, and for recruiting an enzyme that labels the defective protein for degradation. Interestingly, bacteria also have been known to possess proteins similar to the Rqc2 protein of higher organisms. Until now, however, these proteins were thought to have a different function in bacteria.

Using Bacillus subtilis bacteria, the research team at the ZMBH led by Prof. Dr Claudio Joazeiro has now been able to experimentally demonstrate that their Rqc2 protein is also able to recognise incompletely synthesised proteins. However, unlike in higher cells, the Rqc2 protein in bacteria itself marks the aberrant chains; it appends them with a poly-alanine chain to trigger their elimination by the bacterial disposal system. The researchers also showed that this is an important protective mechanism against the cellular stress caused by defective protein production.

The Heidelberg research results demonstrate that the evolutionarily related Rqc2 proteins in bacteria and higher cells perform this quality control function in a similar manner. This led the scientists to conclude that this mechanism must have already existed several billion years ago in the so-called last universal common ancestor, and that this protective function is among the most elemental and essential processes of all cells. In fact, Prof. Joazeiro had previously shown that a mutation preventing the process from functioning causes degeneration of neuronal cells in a similar manner to amyotrophic lateral sclerosis (ALS), a devastating human disease.

An international team of researchers led by scientists at Princeton University has found that a magnetic material at room temperature enables electrons to behave counterintuitively, acting collectively rather than as individuals. Their collective behavior mimics massless particles and anti-particles that coexist in an unexpected way and together form an exotic loop-like structure.

The study was published this week in the journal Science.

The key to this behavior is topology--a branch of mathematics that is already known to play a powerful role in dictating the behavior of electrons in crystals. Topological materials can contain massless particles in the form of light, or photons. In a topological crystal, the electrons often behave like slowed-down light yet, unlike light, carry electrical charge.

Topology has seldom been observed in magnetic materials, and the finding of a magnetic topological material at room temperature is a step forward that could unlock new approaches to harnessing topological materials for future technological applications.

"Before this work, evidence for the topological properties of magnets in three dimensions was inconclusive. These new results give us direct and decisive evidence for this phenomenon at the microscopic level," said M. Zahid Hasan, the Eugene Higgins Professor of Physics at Princeton, who led the research. "This work opens up a new continent for exploration in topological magnets."

Hasan and his team spent more than a decade studying candidate materials in the search for a topological magnetic quantum state.

"The physics of bulk magnets has been understood for many decades. A natural question for us is: Can magnetic and topological properties together produce something new in three dimensions?" Hasan said.

Thousands of magnetic materials exist, but most did not have the correct properties, the researchers found. The magnets were too difficult to synthesize, the magnetism was not sufficiently well understood, the magnetic structure was too complicated to model theoretically, or no decisive experimental signatures of the topology could be observed.

Then came a lucky turning point.

"After studying many magnetic materials, we performed a measurement on a class of room-temperature magnets and unexpectedly saw signatures of massless electrons," said Ilya Belopolski, a postdoctoral researcher in Hasan's laboratory and co-first author of the study. "That set us on the path to the discovery of the first three-dimensional topological magnetic phase."

The exotic magnetic crystal consists of cobalt, manganese and gallium, arranged in an orderly, repeating three-dimensional pattern. To explore the material's topological state, the researchers used a technique called angle-resolved photoemission spectroscopy. In this experiment, high-intensity light shines on the sample, forcing electrons to emit from the surface. These emitted electrons can then be measured, providing information about the way the electrons behaved when they were inside the crystal.

"It's an extremely powerful experimental technique, which in this case allowed us to directly observe that the electrons in this magnet behave as if they are massless. These massless electrons are known as Weyl fermions," said Daniel Sanchez, a Princeton visiting researcher and Ph.D. student at the University of Copenhagen, and another co-first author of the study.

A key insight came when the researchers studied the Weyl fermions more closely and realized that the magnet hosted an infinite series of distinct massless electrons that takes the form of a loop, with some electrons mimicking properties of particles and some of anti-particles. This collective quantum behavior of the electrons has been termed a magnetic topological Weyl fermion loop.

"It truly is an exotic and novel system," said Guoqing Chang, a postdoctoral researcher in Hasan's group and co-first author of the study. "The collective electron behavior in these particles is unlike anything familiar to us in our everyday experience--or even in the experience of particle physicists studying subatomic particles. Here we are dealing with emergent particles obeying different laws of nature."

It turns out that a key driver of these properties is a mathematical quantity that describes the infinite series of massless electrons. The researchers were able to pin down the role of topology by observing subtle changes in the difference of the behavior of electrons living on the surface of the sample and deeper in its interior. The technique to demonstrate topological quantities through the contrasts of surface and bulk properties was pioneered by Hasan's group and used to detect Weyl fermions, a finding published in 2015. The team recently used an analogous approach to discover a topological chiral crystal, work published in the journal Nature earlier this year that was also led by Hasan's group at Princeton and included Daniel Sanchez, Guoqing Chang and Ilya Belopolski as leading authors.

Theoretical predictions

The relationship between the topology and magnetic quantum loop particles was explored in the Hasan group's theoretical predictions published in October 2017 in Physical Review Letters. However, the group's theoretical interest in topological magnets dates back much earlier to theoretical predictions published in Nature Materials in 2010. These theoretical works by Hasan's group were funded by U.S. Department of Energy's office of Basic Energy Sciences.

"This work represents the culmination of about a decade of seeking to realize a topological magnetic quantum phase in three dimensions," Hasan said.

In 2016, Duncan Haldane, Princeton's Sherman Fairchild University Professor of Physics, won the Nobel Prize in Physics for his theories predicting the properties of one- and two-dimensional topological materials.

An important aspect of the result is that the material retains its magnetism up to 400 degrees Celsius--well above room temperature--satisfying a key requirement for real-world technological applications.

"Before our work, topological magnetic properties were typically observed when the thin films of materials were extremely cold--a fraction of a degree above absolute zero--requiring specialized equipment simply to achieve the necessary temperatures. Even a small amount of heat would thermally destabilize the topological magnetic state," Hasan said. "The quantum magnet studied here exhibits topological properties at room temperature."

A topological magnet in three dimensions reveals its most exotic signatures only on its surface--electron wavefunctions take the shape of drumheads. This is unprecedented in previously known magnets and constitute the telltale signature of a topological magnet. The researchers observed such drumhead-shaped electronic states in their data, providing the crucial decisive evidence that it is a novel state of matter.

Patrick Lee, the William & Emma Rogers Professor of Physics at the Massachusetts Institute of Technology, who was not involved in the study, commented on the importance of the finding. "The Princeton group has long been at the forefront of discovering new materials with topological properties," Lee said. "By extending this work to a room temperature ferromagnetic and demonstrating the existence of a new kind of drumhead surface states, this work opens up a new domain for further discoveries."

To understand their findings, the researchers studied the arrangement of atoms on the surface of the material using several techniques, such as checking for the right kind of symmetry using the scanning tunneling microscope in Hasan's Laboratory for Topological Quantum Matter and Advanced Spectroscopy located in the basement of Princeton's Jadwin Hall.

An important contributor to the finding was the cutting-edge spectroscopy equipment used to carry out the experiment. The researchers used a dedicated photoemission spectroscopy beamline recently built at the Stanford Synchrotron Radiation Lightsource, part of the SLAC National Accelerator Laboratory in Menlo Park, California.

"The light used in the SLAC photoemission experiment is extremely bright and focused down to a tiny spot only several tens of micrometers in diameter," said Belopolski. "This was important for the study."

The work was carried out in close collaboration with the group of Professor Hsin Lin at the Institute of Physics, Academia Sinica in Taiwan, and Professor Claudia Felser at the Max Planck Institute for the Chemical Physics of Solids in Dresden, Germany, including postdoctoral researcher Kaustuv Manna as co-first author.

Driven by the tantalizing possibility of applications, the researchers went one step further and applied electromagnetic fields to the topological magnet to see how it would respond. They observed an exotic electromagnetic response up to room temperature, which could be directly traced back to the quantum loop electrons.

"We have many topological materials, but among them it has been difficult to show a clear electromagnetic response arising from the topology," Hasan added. "Here we have been able to do that. It sets up a whole new research field for topological magnets."

Northeastern Texas has borne the brunt of Tropical Depression Imelda's heavy rainfall and NASA estimated that rainfall with an algorithm that incorporates data from satellites and observations.

By Thursday morning, September 19, Tropical Storm Imelda had dropped over 10 inches of rain over a large area between Houston and Beaumont, Texas. At NASA's Goddard Space Flight Center in Greenbelt, Maryland, a graphic was produced that shows precipitation that fell starting on Tuesday, September 17, the day that Imelda formed as a tropical depression in the Gulf of Mexico, intensified into a tropical storm, and made landfall in Texas, all within a few hours.

The near-realtime rain estimate comes from the NASA's Integrated Multi-satellitE Retrievals for GPM (IMERG) algorithm, which combines observations from a fleet of satellites, in near-realtime, to provide near-global estimates of precipitation every 30 minutes.  This satellite-based rain estimate is somewhat coarse in resolution and can miss short-lived, intense storm-cells, but the IMERG algorithm often does captures the large-scale features of storms wherever they form in the world.  While the United States is fortunate to have a network of ground radars that can provide higher-resolution precipitation estimates, in other parts of the world, notably over most of the world's oceans, the IMERG rain estimate is an important reference point.

By combining NASA precipitation estimates with other data sources, we can gain a greater understanding of major storms that affect our planet.

NOAA's Storm Prediction Center also reported several preliminary reports of tornadoes on Wednesday evening, September 18.

On September 19 at 5 a.m. EDT, NOAA's National Weather Service Weather Prediction Center (NWS NPC) in College Park, Md. forecast indicated that Imelda's heavy rainfall is expected to continue. Flash flood watches are in effect for parts of eastern Texas and western Louisiana.

The NWS forecasts that Imelda is expected to produce the following rainfall amounts through Friday: Across the Upper Texas Coast into far southeast Texas... an additional 5 to 10 inches with isolated storm totals of 25 to 35 inches are possible. Across portions of southwest Louisiana...an additional 3 to 5 inches with isolated totals of 10 inches are expected. For the rest of east Texas...2 to 4 inches with isolated totals around 8 inches are forecast. These rainfall totals may produce significant to life threatening flash floods.

At 5 a.m. EDT (0900 UTC), the center of Tropical Depression Imelda was located near latitude 31.3 North, longitude 95.5 West. That puts the center of Imelda's circulation about 110 miles (180 km) north of Houston, Texas and about 70 miles (115 km) northeast of College Station, Texas.  The depression is moving toward the north-northwest near 5 mph (7 kph) and this motion is expected to continue through today. Maximum sustained winds are near 30 mph (45 kph) with higher gusts. The estimated minimum central pressure is 1009 millibars. A gradual weakening is forecast during the next 24 hours.

Hurricanes are the most powerful weather event on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

For more information about NASA's IMERG, visit: https://pmm.nasa.gov/gpm/imerg-global-image

For updated forecasts on Imelda, visit: http://www.nhc.noaa.gov

Is your kid obsessed with video games and hanging out with questionable friends? These are common traits for involvement in cybercrime, among other delinquencies. New research from Michigan State University identified characteristics and gender-specific behaviors in kids that could lead them to become juvenile hackers.

"We know much about the scope of hacking and its threat, but the problem is that we don't know exactly when and how hacking behavior starts," said Thomas Holt, lead author and MSU cybercrime expert in the School of Criminal Justice. "There is a general understanding that hacking starts in the early teens but until now, we weren't clear on background factors, such as behavioral issues, the impact of social connections or personality traits. Our findings pointed us in the direction of thinking that there are gendered pathways to hacking."

Holt assessed responses from 50,000 teens from around the world to determine predictors of hacking. The findings, published in Crime & Delinquency, are the first to dig into gendered differences from a global data set.

"We found that predictors of juvenile delinquency, like low self-control - so, not having the ability to hold back when opportunity presents itself - are big factors for computer hacking for both boys and girls," Holt said. "But for girls, peer associations mattered more. If she has friends who shoplift or engage in petty forms of crime, she's more likely to be influenced to hack as well. For boys, we found that time spent watching TV or playing computer games were associated with hacking."

Holt explained that the stark differences between boys and girls were quite distinct, reinforcing the idea that girls get into hacking in ways that greatly differed from boys. He said that some of the findings play to how kids are raised within gender roles, such as letting boys play video games and giving girls different activities.

For boys and girls, simply having opportunities to hack were significant in starting such behavior.

This could include having their own bedroom, their own computer or the freedom of doing what they want on the internet without parental supervision.

While most schools have computer and internet access, Holt explained that there are still some geographic barriers for kids to enter cybercrime. The researchers found that kids who had mobile phone access early on were more likely to hack - especially if they lived in larger cities. Spending time with peers was more likely to influence delinquent behavior for those living in smaller cities. The researchers also found a connection between pirating movies and music and hacking.

In the 1980s and 1990s, juvenile hacking was mostly limited to gaming purposes, and even now most initial cybercrime isn't serious, such as getting into Facebook or email accounts, Holt said.

"The initial attempts might not be serious, but without supervision and low self-control, it's likely they got a taste for what they might be able to accomplish by taking their hacking abilities further," Holt said. "And while low self-control plays a huge role with kids and teens, some of them mature as they age and can sit for hours, which gives them time to refine the skills of a sophisticated hacker."

It's important for parents to understand their kids' tech-savviness and habits to help guide them on a path that uses their skills in a more positive way.

"Parents shouldn't assume that having a kid with sophisticated technological competency is always totally fine," Holt said. "Finding others in the field - like those you'd meet in a robotics club or attending something like the DefCon conference - is vital for kids to learn about using their skills in a positive way and for staving off bad behaviors," Holt said. "Cybercrime can be a hidden problem, so talking is vital. The more you can understand what they're doing, the easier you can flag something that might be off and curtail activity."