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Humans a more immediate threat to large river systems than climate change

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June 19 (UPI) — Climate change promises to disrupt a variety of natural systems across the globe, but new research suggests human activities pose a more immediate threat to the planet’s largest river systems.

For the study — published Friday in the journal One Earth — scientists synthesized past work on the most significant stressors affecting large rivers.

The new survey identified a variety of human activities that hamper the natural resiliency of major river systems, including: damming, dredging, land-use change, pollution, introduction of non-native species, water diversion and subsidence caused by groundwater extraction.

“These are in addition to those of climate change — flooding and droughts — and greenhouse-gas linked sea-level rise,” lead study author Jim Best told UPI in an email.

“The thrust of our paper is that these other stressors may pose a more immediate threat in many large rivers, and that they can reduce resilience thresholds that then makes these rivers more vulnerable to the effects of climate-change induced stresses,” said Best, a professor of geology and geography at the University of Illinois at Urbana-Champaign.

The crux of the paper echoes the warnings issued by a variety of other recent studies — that the threat of rising temperatures and rising seas has overshadowed other serious ecological problems, from habitat loss and overfishing to invasive species and agricultural runoff.

The warnings have moved scientists and policy makers with United Nations to emphasize the importance of addressing worrying land-use trends and biodiversity losses as part of the broader solution to climate change.

“Our main point is that we worried that the understandable concern about dangerous climate change — which is real and warranted — has meant that in some cases the main causes of dangerous environmental change are sometimes overlooked,” study co-author Stephen Darby, professor of physical geography at the University of Southampton, told UPI.

In their paper, Best and Darby compiled data detailing the human activities threatening the health of the Mekong River in Southeast Asia.

The Mekong Delta is increasingly vulnerable to damaging floods as a result of subsidence, or sinking, a problem exacerbated by groundwater extraction and slowing rates of sedimentation. As more dams get built in the region, less sediment makes its way downstream.

The Mekong isn’t alone. Rivers all over the world, big and small, face both the threat of climate change and those posed by human activities.

“Rivers such as the Mississippi have huge issues with nutrient loading and hypoxia in the Gulf of Mexico; the Huang He and Chang Jiang, or Yellow and Yangtze, rivers have seen significant changes to their flow and sediment loads due to damming, as well as large-scale water diversions across China,” Best said.

“The Ganges is struggling with pollution from a wide range of causes; macro and micro plastic pollution is common in many rivers, large and small, and feeding this waste into the world’s oceans,” Best said.

According to the study’s authors, addressing the threats posed by human activities, like water diversion and agricultural runoff, won’t require policy makers to ignore climate change. In fact, they argue working to safeguard river systems from human activities will make river systems more resilient to the threat of rising sea levels and extreme weather.

Of course, the opposite is also true. Harmful human activities, if left unchecked, are likely to make river systems more vulnerable to the impacts of climate change, the researchers said.

“The other stressors mentioned above, and not just climate change, likely compound the effects that climate change, through increased flooding or drought, may have, potentially making these landscapes more vulnerable to extreme events,” Best said.

In the Mekong River Delta, for example, rising sea levels have led to the encroachment of saline water into freshwater ecosystems. This problem is being made worse by sediment starvation caused by upstream damming and sediment mining.

More than just threaten river health, this negative feedback loop caused by both climate change and human activity has begun to harm regional economies.

“The compound effects of these stresses are influencing the types of agriculture, and agricultural production, for this vital region. These other stressors of sediment starvation and subsidence are yielding far larger effects on a shorter timescale than just sea-level rise,” Best said.



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‘Invisible’ words reveal common structure among famous stories

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Aug. 7 (UPI) — Storytelling requires a narrative arc, but the trajectory of a dramatic arc isn’t always obvious.

By tracing the abundance of “invisible” words — pronouns, articles and other short words — researchers were able to identify patterns shared by a diversity of stories, from Shakespeare to Spielberg, according to a study published Friday in Science Advances.

“Over the years, these ‘invisible’ words have been found to be related to a whole mess of psychological processes — how people use small words like articles and pronouns tell us about a person’s mental health, thinking style, their social status, and even how well they get along with other people,” study lead author Ryan Boyd told UPI.

“In many ways, it was a natural progression to look at what these words can tell us how the nature of stories,” said Boyd, a lecturer in behavioral analytics at the University of Leeds.

For the study, Boyd and his colleagues used a range of statistical techniques to analyze the abundance and distribution of invisible words in 40,000 fictional texts, including short stories, novels and movie scripts.

The analysis revealed a common structure — a so-called narrative curve — featuring three distinct phases.

During the “staging” phase, authors use prepositions and articles in greater abundance, peppering their prose with “a” and “the.” These words are more useful at the beginning, when authors must set the scene and provide the audience with basic information.

The middle phase is defined by plot progression, which is revealed by a greater abundance of auxiliary verbs, adverbs and pronouns — or interactional language. During this phase, “the house” from the staging phase becomes “her home” or “it.”

During the third phase, cognitive tension is ramped up as the narrative arc reaches a climax. As the author guides the reader or viewer through the process of conflict resolution, cognitive-processing words like “think,” “believe,” “understand” and “cause” begin to crop up in greater numbers.

Researchers found this three-phase narrative shape remained consistent, regardless of a stories length.

“A 25,000 word story has the same shape as a 250 word story,” said Boyd, lead author of the new study. “It seems, then, that we are able to do a good job of structuring our stories in an optimal way regardless of how much space we have to do it in.”

The researchers set up a website showing the shapes of staging, plot progression and cognitive tension in eight texts at The Arc of Narrative website.

The patterns left by invisible words proved both good and bad stories — tales spun by amateurs, as well as professionals — utilize similar structures.

“Our results confirm what people have long believed about stories,” Boyd said. “Like DNA, we knew about it long before we could actually see it and measure it. With these new methods, we are able to see and measure the ‘DNA’ of stories and understand them in more objective, scientific ways.”

According to Boyd, studying the patterns of stories can offer insights into cognitive processes unique to humans.

“What these story shapes seem to tell us is that we have, to some degree, evolved to process information in certain ways,” he said. “We need to understand the ‘who’ and ‘what’ in order to understand the ‘why’ of our everyday lives and the lives of others.”

The authors of the latest story are already mining text for other language patterns that might help researchers determine whether a story-teller is telling the truth, or perhaps reveal the secrets to a “good” story.



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Florida Current study confirms decline in strength of Gulf Stream

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Aug. 7 (UPI) — New research suggests the strength of the Florida Current, which forms the beginning of the Gulf Stream, has weakened considerably over the last century.

The findings, published Friday in the journal Nature Climate Change, corroborate the predictions of several models that suggest the Gulf Stream has slowed over the last several decades.

The Florida Current is a thermal ocean current that flows from west to east around the tip of Florida, joining the Gulf Stream off Florida’s east coast.

Scientists have been tracking the strength of the Florida Current since the early 1980s — not long enough to identify multi-decadal or centennial trends.

To better understand the current’s historical changes, Christopher Piecuch, researcher at the Woods Hole Oceanographic Institution in Massachusetts, decided to study the relationship between coastal sea level and the strength of near-shore currents.

While researchers have only been measuring the Florida Current for a few decades, scientists have been recording sea level data since the early 1900s. Piecuch was able to use the data to predict historic changes in the strength of near-shore currents.

“In the ocean, almost everything is connected,” Christopher Piecuch, sole author of the new study, said in a news release. “We can use those connections to look at things in the past or far from shore, giving us a more complete view of the ocean and how it changes across space and time.”

The statistical analysis performed by Piecuch showed the Florida Current and Gulf Stream are the weakest they’ve been during the last 110 years.

The findings are in agreement with ocean current models that suggest climate change has caused a slowdown of the Atlantic Meridional Overturning Circulation, of which the Gulf Stream is a part.

Piecuch said he hopes his research will help other scientists use coastal current data to study changes in bigger currents like the Gulf Stream.

“If we can monitor something over the horizon by making measurements from shore, then that’s a win for science and potentially for society,” he said.



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SpaceX, ULA win large government launch contracts

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Astronauts make round trip to space station from U.S. soil

NASA astronaut Douglas Hurley (C) waves to onlookers as he boards a plane at Naval Air Station Pensacola to return him and NASA astronaut Robert Behnken home to Houston a few hours after the duo landed in their SpaceX Crew Dragon Endeavour spacecraft off the coast of Pensacola, Fla,, on August 2, 2020. Photo by Bill Ingalls/NASA | License Photo



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