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Categories: Geoscience: Geomagnetic Storms, Paleontology: Climate

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Researchers have uncovered the first direct evidence that the West Antarctic Ice Sheet shrunk suddenly and dramatically at the end of the Last Ice Age, around eight thousand years ago. The evidence, contained within an ice core, shows that in one location the ice sheet thinned by 450 meters -- that's more than the height of the Empire State Building -- in just under 200 years.

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Inspired during field work in South Australia's Flinders Ranges, geoscientists have proposed that all-time low volcanic carbon dioxide emissions triggered a 57-million-year-long global 'Sturtian' ice age.

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A new study provides the first evidence that the Arctic's frozen soil is the dominant force shaping Earth's northernmost rivers, confining them to smaller areas and shallower valleys than rivers to the south. But as climate change weakens Arctic permafrost, the researchers calculate that every 1 degree Celsius of global warming could release as much carbon as 35 million cars emit in a year as polar waterways expand and churn up the thawing soil.

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The brown bear is one of the largest living terrestrial carnivores, and is widely distributed across the Northern Hemisphere. Unlike many other large carnivores that went extinct at the end of the last Ice Age (cave bear, sabretoothed cats, cave hyena), the brown bear is one of the lucky survivors that made it through to the present. The question has puzzled biologists for close to a century -- how was this so?

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A new method predicts how much flooding a coastal community is likely to experience as hurricanes evolve due to climate change. Using New York as a test case, the model predicts Hurricane Sandy-level flooding will occur roughly every 30 years by 2099.

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A new way to measure the ocean oxygen level and its connections with carbon dioxide in the Earth's atmosphere during the last ice age could help explain the role oceans played in past glacial melting cycles and improve predictions of how ocean carbon cycles will respond to global warming.

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The new theoretical research proposes that animal size over time depends on two key ecological factors.

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Southern Africa contains the vast majority of the world's remaining populations of both black and white rhinoceroses (80% and 92%, respectively). The region's climate is changing rapidly as a result global warming. Traditional conservation efforts aimed at protecting rhinos have focused on poaching, but until now, there has been no analysis of the impact that climate change may have on the animals. A research team has recently reported that, though the area will be affected by both higher temperatures and changing precipitation, the rhinos are more sensitive to rising temperatures, which will quickly increase above the animals' acceptable maximum threshold.

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When combined with data from tree-ring records, stalagmites can open up a unique archive to study natural climate fluctuations, a research team has demonstrated. The researchers analyzed the isotopic composition of oxygen in a stalagmite formed from calcareous water in a cave in southern Germany. In conjunction with the data acquired from tree rings, they were able to reconstruct short-term climate fluctuations over centuries and correlate them with historically documented environmental events.

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New research has precisely dated some of the oldest fossils of complex multicellular life in the world, helping to track a pivotal moment in the history of Earth when the seas began teeming with new lifeforms -- after four billion years of containing only single-celled microbes.

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Human activity, from burning fossil fuels and fireplaces to the contaminated dust produced by mining, alters Earth's atmosphere in countless ways. Records of these impacts over time are preserved in everlasting polar ice that serves as a sort of time capsule, allowing scientists and historians to link Earth's history with that of human societies. In a new study, ice cores from Antartica show that lead and other toxic heavy metals linked to mining activities polluted the Southern Hemisphere as early as the 13th century.

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A new study shows how state-of-the-art methods and perspectives from archaeology, history, and palaeoecology are shedding new light on 5,500 years of urban life.

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Early in the 1970s, paleontologists discovered strange fossilized fruits between hardened rock from one of the largest volcanic eruptions in Earth's history. The identity of these fossils remained elusive for the next several decades. Using CT scanning, scientists have now determined they are the oldest fossils from species in the Frankincense and Myrrh family.

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Simulations integrate historical records, fossils, and ancient DNA to reveal why the European bison nearly went extinct, and pinpoint optimal areas for conservation.   Since the near-extinction of the European bison, enormous conservation efforts have helped to restore wild populations, and its numbers are on the rise. However, the study authors argue that ensuring the species's long-term protection and recovery requires understanding why they nearly went extinct in the first place.    'Our study also suggests areas where rewilding attempts are most likely to be successful,' said lead author July Pilowsky, currently a disease ecologist at Cary Institute of Ecosystem Studies. Pilowsky completed the research while working on their PhD at University of Adelaide and University of Copenhagen.   

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Train accidents could be caused by solar storms switching signalling from red to green according to new research examining the impact of space weather. Solar storms can trigger powerful magnetic disturbances on Earth, creating geomagnetically induced currents which could potentially interfere with electricity transmission and distribution grids. A study of two rail lines showed that more serious 'wrong side' failures (red to green) could occur with a weaker solar storm than for 'right side' failures, posing a serious risk which the industry needs to take on board.  

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While auroras occur at high latitude, the associated phenomena Steve and the picket fence occur farther south and at lower altitude. Their emissions also differ from aurora. A physics graduate student has proposed a physical mechanism behind these emissions, and a rocket launch to test the theory. She argues that an electric field in the upper atmosphere parallel to Earth's magnetic field could explain the green picket fence spectrum and perhaps Steve and the enhanced aurora.

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An international consortium of geoscientists has reconstructed atmosphereric levels of carbon dioxide going back 66 million years using proxies in the geoloogical record. Today's concenteration, 420 parts per million, is higher than it's ever been in 14 million years.

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New research has shown that fire-ice -- frozen methane which is trapped as a solid under our oceans -- is vulnerable to melting due to climate change and could be released into the sea.

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In southern Germany just north of the Danube, there lies a large circular depression between the hilly surroundings: the Nördlinger Ries. Almost 15 million years ago, an asteroid struck this spot. Today, the impact crater is one of the most useful analogues for asteroid craters on early Mars. Studying the deposits of the former lake that formed in the crater is particularly informative. These deposits have been of great interest ever since NASA began exploring Martian craters for signs of water and life on Mars.

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What wiped out the dinosaurs? A meteorite plummeting to Earth is only part of the story, a new study suggests. Climate change triggered by massive volcanic eruptions may have ultimately set the stage for the dinosaur extinction, challenging the traditional narrative that a meteorite alone delivered the final blow to the ancient giants.