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NWT_Earth NWT_Environment SCI

Antarctic snowfall increased over the last two centuries

Antarctica has experienced a 10 percent increase in snowfall over the last 200 years, according to recent research set to be presented at the European Geosciences Union in Vienna, Austria

This new discovery comes from a group of scientists with the British Antarctic Survey, who analyzed Antarctic ice cores and found that the continent accumulated nearly 272 gigatons of water over the last two centuries. Almost all of that extra water came from increased snowfall.

Such information is important because, not only does it alter the current perception of Antarctica’s climate, but it could change current sea level rise models as well.

“There is an urgent need to understand the contribution of Antarctic ice to sea-level rise and we use a number of techniques to determine the balance between snowfall and ice loss,” lead author Elizabeth Thomas, a researcher with the British Antarctic Survey, said in a statement. “When ice loss is not replenished by snowfall then sea level rises.”

Satellite pictures — which often help researchers understand shifting climates — typically only give information going back 20 years or so. As a result, ice core analysis, which are able to track snowfall for several hundred years, are more effective. In this case, they revealed that Antarctica’s surface mass balance drastically shifted from snowfall throughout the twentieth century.

Though the snowfall is everywhere, it mainly concentrated on the Antarctic Peninsula. There, the annual average is 10 percent higher than it was 200 years ago.

This discovery could alter current perceptions of climate change, but the team states the findings do not override any observations of melting or glacial retreat. Even so, they will allow scientists make more accurate sea level rise predictions as time goes on.

“We know that the two major influencers affecting change — the mass gain from snowfall and the mass loss from melting — are acting differently from one another,” added Thomas, according to UPI. “Our new findings take us a step towards improving our knowledge and understanding.”

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NWT_Earth Research SCI

Life on Earth evolved earlier than previously thought, study says

Researchers from the University of Bristol have created a new timescale of life on Earth, which suggests that it evolved earlier than we previously thought. The new study combined fossil and genomic data to come to its surprising conclusion.

The fossil record on Earth is very fragmented, with a significant deterioration observed back in time towards the Archaen period that took place over 2.5 billion years ago. During this time, the Earth’s crust cooled enough to pave the way for the formation of continents and microbe lifeforms.

“There are few fossils from the Archaean and they generally cannot be unambiguously assigned to the lineages we are familiar with, like the blue-green algae or the salt-loving archaebacteria that colours salt-marshes pink all around the world,” said Holly Betts, lead author of the study.

“The problem with the early fossil record of life is that it is so limited and difficult to interpret—careful reanalysis of the some of the very oldest fossils has shown them to be crystals, not fossils at all,” she continued.

By combining genomic and fossil information, the team found that the Last Universal Common Ancestor (LUCA) of all cellular life forms existed nearly 4.5 billion years ago, which is earlier than the oldest known fossil evidence suggests.

“Our results indicate that two ‘primary’ lineages of life emerged from LUCA (the Eubacteria and the Archaebacteria), approximately one Billion years after LUCA,” said co-author and professor Davide Pisani.

“This result is testament to the power of genomic information, as it is impossible, based on the available fossil information, to discriminate between the oldest eubacterial and archaebacterial fossil remains,” he added.

The findings were published in Nature Ecology & Evolution.

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NWT_Climate NWT_Earth NWT_Environment SCI

Ocean acidification is majorly impacting marine life, study says

A new study continues to shed light on the effects of industrial development on our seas by revealing that carbon dioxide emissions are destroying kelp forests and corals reefs. The damages are reportedly from the ocean acidification and heat waves created by climate change.

“These CO2 seeps provide a vital window into the future,” said lead author Sylvain Agostini, Associate Professor at the University of Tsukuba Shimoda Marine Research Centre. “There was mass mortality of corals in the south of Japan last year, but many people cling to the hope that corals will be able to spread north.”

“Therefore it is extremely worrying to find that tropical corals are so vulnerable to ocean acidification, as this will stop them from being able to spread further north and escape the damage caused by water that is too hot for them,” he continued.

“Our research site is like a time machine,” said Jason Hall-Spencer, Professor of Marine Biology at the University of Plymouth. “In areas with pre-Industrial levels of CO2 the coast has an impressive amount of calcified organisms such as corals and oysters. But in areas with present-day average levels of surface seawater CO2 we found far fewer corals and other calcified life, and so there was less biodiversity.”

The new data shows the large amount of damage stemming from human-created carbon dioxide emissions over the last 300 years.

“Unless we can get a grip on reducing CO2 emissions we will undoubtedly see major degradation of coastal systems worldwide,” Hall-Spencer said.

The findings were published in Scientific Reports.

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NWT_Earth TECH

‘Slow earthquakes’ on San Andreas Fault raise risks of massive quakes

New interpretations by two Arizona State University geophysicists reveal that the earth movements along a central section have not been smooth and steady, as previously estimated.

The activity has been a sequence of small stick-and-slip movements referred to as “slow earthquakes” which release energy over a period of months.

Researchers say they can trigger large destructive quakes in their surroundings. One such quake was the magnitude 6 event that shook Parkfield in 2004.

Mostafa Khoshmanesh, a graduate research assistant in ASU’s School of Earth and Space Exploration (SESE), states, “What looked like steady, continuous creep was actually made of episodes of acceleration and deceleration along the fault.”

“We found that movement on the fault began every one to two years and lasted for several months before stopping,” said Manoochehr Shirzaei, assistant professor in SESE and co-author of the paper.

Episodic slow earthquakes result in prolonged stress on the locked segments of the fault to the north and south of the central section.

Shirzaei notes that these flanking sections experienced two magnitudes 7.9 earthquakes, in 1857 (Fort Tejon) and 1906 (San Francisco).

The scientists also suggest a mechanism that might cause the stop-and-go movements.

“Fault rocks contain a fluid phase that’s trapped in gaps between particles, called pore spaces,” Khoshmanesh said. “Periodic compacting of fault materials causes a brief rise in fluid pressure, which unclamps the fault and eases the movement.”

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NWT_Earth TECH

Earth’s rivers cover 44 percent more land than recognized

A new global map of rivers and streams created using satellite data suggests that the global surface area of these bodies of water is about 44% higher than previously thought, according to the American Association for the Advancement of Science.

Particularly two studies to date have attempted to quantify the global surface area of rivers, noting that these were based on limited data.

Important and complex chemical exchanges with the atmosphere and biosphere happen at the water-atmosphere interface of rivers. The study provides examples, such as rivers releasing roughly one-fifth of the carbon dioxide levels emitted by fossil fuel combustion and cement production.

Using satellite data, George Allen and Tamlin Pavelsky created one of the most detailed databases of rivers and streams to date, called the Global River Widths from Landsat (GRWL) Database. It quantifies the surface area of rivers greater than 90 kilometers (km) in width.

The authors performed a series of calculations to account for smaller rivers, for which less data is available. Collectively, global rivers and streams were estimated to cover roughly 773,000 km2 of Earth’s global non-glaciated land surface – tens of thousands of kilometers squared higher than previous estimates.

Regionally, authors Allen and Pavelsky report more river surface area coverage in the Arctic, distinctly where the impacts of climate change on carbon fluxes are of a major concern than previous estimates have ballparked. Remarkably, the report displays less in Europe, the U.S., and other economically developed regions.

Allen and Pavelsky note that the “lower-than-previous estimate of river surface area” in many developed areas may suggest large-scale impacts of human modification on river networks, emphasizing the hypothesis necessitates additional examination.

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NWT_Earth NWT_Environment

Global warming signs are everywhere

While it is easy to assume that climate change only comes in the form of rising oceans or extreme weather events, signs of global warming are all around us every single day.

An example of this comes from David Inouye, a researcher from the University of Maryland who studied when wildflowers and their pollinators began appearing around the Rocky Mountain Biological Lab. Diligent research over numerous decades revealed the species show up roughly two to three weeks earlier — mid-March as opposed to early April — than they did 30 years ago. In addition, birds also show up earlier and marmots end their winter slumber before they used to.

‘‘If the climate weren’t changing, we wouldn’t see these kind of changes happen,’’ explained Inouye, according to The Boston Globe.

It has been almost 30 years since scientists began analyzing global warming. Though the climate is the main focus, new studies show that all of nature has gone through shifts.

In fact, interviews with more than 50 scientists combined with an Associated Press analysis of data on plants, animals, pollen, ice, and sea levels show just how impactful the process is.

That research showed that there are 28,800 cases of plants and animals ‘‘responding consistently to temperature changes.’’ Blueberry patches at Walden Pond now bloom earlier as a result of warmer temperatures while many species come out of hibernation at different times.

Spring now occurs earlier than it used to, and fall starts much later on. All of those shifts have massive impacts on different ecosystems and radically change both animal and plant behavior.

It can affect humans as well. For instance, studies on ragweed growth shows that warmer springs lead to an increased number of high pollen days. Allergies and asthma are also both on the rise.

While climate change is not the only reason for these shifts, it is a primary factor and something scientists hope officials keep in mind moving forward.

‘‘If you don’t trust the thermometers, throw them out,’’ said Katharine Hayhoe, a climate scientist at Texas Tech, according to The Washington Post. ‘‘All we have to do is look at what’s happening in nature.’’

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NWT_Earth NWT_Environment

Antarctica steadily rising over time, study reports

Thinning ice has caused bedrock deposits underneath Antarctica to rise higher than ever before, a new study published in the journal Science reports.

As ice melts, it takes weight off the bedrock below. Though that process does not happen right away, large amounts of ice have melted across Antarctica through the years. That in turn caused the bedrock to rise up in response.

This new finding — which comes from researchers at the Technical University of Denmark — is both good and bad news.

It is good news because the uplift of supporting bedrock may help anchor other ice sheets and make them more stable. However, the rising rock has likely skewed past satellite measurements on ice loss and those predictions may be underestimated by as much as 10 percent.

Though computer models help scientists understand how the Earth’s mantle behaves, they do not have a full idea of the different reactions that drive its mechanisms. These findings are a good example of such processes, and they could shed more light on the geological movements of our planet.

“The study of this — the distribution of viscosity in the mantle — is still in its infancy,” said lead study author Valentina Barletta, a postdoctoral researcher at DTU Space, the National Space Institute at the Technical University of Denmark, according to Live Science. “We know where the Earth is hotter and cooler — more or less. However, the viscosity of the mantle depends not just on temperature, but also on water content.”

While scientists previously believed changes like the ones in the recent study took tens of thousands of years, the newly documented process occurred over decades. That suggests the mantle under Antarctica may flow more quickly than previously suspected.

To measure those changes, the team installed six GPS stations at locations around a region of the ice sheet known as the Amundsen Sea Embayment (ASE). They placed the monitors at exposed bedrock and gathered data at a spatial resolution of 0.6 miles.

That revealed the rising bedrock.

The team hopes this new information will be incorporated into models and help inform future decisions. 

“These data will be of great value to the modeling community who examine the complex relationships between GIA, sub-ice shelf ocean circulation, and ultimately, ice sheet stability,” said Doug Kowalewski, the Antarctic Earth Sciences program director in the National Science Foundation’s Office of Polar Programs (OPP) who was not involved in the research, according to Phys.org.

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NWT_Earth NWT_Environment

Global tourism leaves a huge carbon footprint, study reports

Global tourism accounts for roughly 8 percent of carbon emissions on Earth, a new study in Nature Climate Change reports.

Though researchers have long been aware of a link between tourism and global warming, this new estimate is three times larger than previous ones. That is because it includes emissions from travel in addition to the full-life cycle of carbon from food, hotels, and shopping.

Tourism — which brings in over $7 trillion a year and employs 1 in 10 people around the world — grows at a steady rate of 4 percent a year. That is great news for travelers, but it could be a big problem for the Earth.

In the past, studies revealed that carbon generated by tourism accounted for 2.5 to 3 percent of emissions on Earth. However, this new research from scientists at the University of Sydney analyzed global carbon flows between 160 countries from 2009 and 2013 and found the 8 percent estimate.

Though that larger number is concerning, the team also included an analysis that looks at the energy needed to support the tourism system. They have a plan that could cover food, beverages, infrastructure construction, maintenance, and retail services.

“It definitely is eye opening,” study co-author Arunima Malik, a researcher from the University of Sydney, told BBC News.”We looked at really detailed information about tourism expenditure, including consumables such as food from eating out and souvenirs. We looked at the trade between different countries and also at greenhouse gas emissions data to come up with a comprehensive figure for the global carbon footprint for tourism.”

Researchers also analyzed the impacts on countries where tourists both originate from and travel to. That revealed relatively well-off people from affluent nations going to other well-off destinations causes more of an impact that any other factor.

For instance, people travelling from Canada, Switzerland, the Netherlands, or Denmark create a much larger carbon footprint in other countries than their own. In addition, when measuring per capita emissions, tourism generates roughly 80 percent of emissions in small islands like the Maldives and Cyprus.

That is likely because rich people spend a lot on luxuries like food and travel. The team discovered that carbon footprints from tourism increase 13 percent for every 10 percent rise in income.

That link is cause for concern and one researchers plan to watch in the coming years.

To help stem the tide, scientists state that the practice of offsetting — where tourists spend money to plant trees to negate their impact — needs to increase. The team also hopes the research will raise awareness and help people understand how climate change can affect important resources.

“Exploring new places and new things — that’s a happy kind of thing,” added Malik, according to The Los Angeles Times. “We just want people to realize that it’s also responsible for carbon emissions.”

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NONE NWT_Climate NWT_Earth NWT_Environment

Rising sea levels could sink Internet access for millions of users

Millions of Internet users could lose Internet access within the next 15 years due to rising sea levels, warns a new study by researchers at the University of Wisconsin and University of Oregon. The study noted that thousands of miles of fiber-optic cables are located along the world’s coastlines and are at risk of being engulfed by seawater by 2033 if current forecasts of sea-level rise brought on by global warming come true.

“Climate change-related sea level incursions could have a devastating impact on Internet communication infrastructure even in the relatively short term,” the report states.

The report combines sea-level rise projects by the National Oceanic and Atmospheric Administration with data of physical Internet infrastructures across the globe from the Internet Atlas. It finds that water levels could engulf around 4,067 miles of fiber conduit and 1,101 data centers and connection points over the next 15 years, wrecking Internet operability across coastlines and throughout such densely populated coastal cities as Miami, New York City, and Seattle.

Fiber-optic cables can withstand some heavy rainfall and adverse weather, but they are not waterproof. Study authors Paul Barford, Carol Barford, and Ramakrishnan Durairaian wrote that these cable networks are “not designed to be under water permanently.”

Even more cable damage could arise from severe storms, the authors added. They noted that major network disruptions occurred during recent mega-storms such as hurricanes Katrina and Sandy—and researchers expect more storms like these as climate change unfolds.

Internet users further inland wouldn’t be safe, either. The report warns that damage to these cables would compromise Internet access potentially all across the globe.

 

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NWT_Earth NWT_Environment

Greenland ice steam has long been susceptible to climate change, study reports

A team of international scientists have discovered that the Northeast Greenland Ice Stream (NEGIS) is much more susceptible to climate change than previously thought.

 

The NEGIS is 300 miles long and drains nearly 12 percent of the Greenland ice sheet. While it, like so many natural formations, melted significantly in recent years, the new study shows the stream started retreating as early as 45,000 years ago. 

“There are some parts of the ice sheet that are relatively stable and others that show evidence of very rapid retreating — a pattern we’re seeing today as well as thousands of years ago,” said study co-author Anders Carlson, a geologist at Oregon State University, according to Tech Times. “Some of it relates to bed topography — when the bed is below sea level, it stabilizes that part of the ice sheet. In low spots, it is unstable.”

The team made that discovery by noting the NEGIS experienced a large loss of ice between 41,000 and 26,000 years ago. Though they are not sure, scientists believe that event was the result of both warm summer months and low snowfall in the winter. In addition, the Earth’s orbit was much closer to the sun then than it is today.

Researchers analyzed such changes by reconstructing changing air temperatures and studying rocks in the NEGIS to determine how the sun affected it. Such analysis was key because it enabled scientists to determine where the ice sheet margins were. That then revealed the rocks were exposed to cosmic rays at one point in time, a process that led the NEGIS to shrink.

That information is important because it could help scientists get a better understanding of the formation and plan for what could occur as the Earth continues to warm.

“Modern observations have shown that the NEGIS is very susceptible to changes in both air and ocean temperatures and is presently in a phase of rapid ice retreat,” said lead author Nicolaj Larsen, a researcher at Aarhus University in Denmark, according to Science Daily.

While current estimates show the NEGIS is not likely to retreat until the end of the century, the vanishing ice in Greenland could have a lasting impact on the rest of the world. Less ice could further climate change. In addition, melting ice may also lead sea levels to rise.

The study is outlined in the journal Nature Communications.