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Categories: Paleontology: Climate
Published Ice age could help predict oceans' response to global warming
(via sciencedaily.com) Original source 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.
Published Why animals shrink over time explained with new evolution theory
(via sciencedaily.com) Original source The new theoretical research proposes that animal size over time depends on two key ecological factors.
Published The heat is on: Scientists discover southern Africa's temps will rise past the rhinos' tolerance
(via sciencedaily.com) Original source 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.
Published Stalagmites as climate archive
(via sciencedaily.com) Original source 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.
Published Key moment in the evolution of life on Earth captured in fossils
(via sciencedaily.com) Original source 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.
Published The first assessment of toxic heavy metal pollution in the Southern Hemisphere over the last 2,000 years
(via sciencedaily.com) Original source 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.
Published Ancient cities provide key datasets for urban planning, policy and predictions in the Anthropocene
(via sciencedaily.com) Original source 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.
Published Mysterious fruit shown to be the oldest known fossils of the Frankincense and Myrrh family
(via sciencedaily.com) Original source 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.
Published Best areas for rewilding European bison
(via sciencedaily.com) Original source 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.
Published Geoscientists map changes in atmospheric carbon dioxide over past 66 million years
(via sciencedaily.com) Original source 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.
Published Climate change shown to cause methane to be released from the deep ocean
(via sciencedaily.com) Original source 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.
Published Limitations of asteroid crater lakes as climate archives
(via sciencedaily.com) Original source 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.
Published More than a meteorite: New clues about the demise of dinosaurs
(via sciencedaily.com) Original source 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.
Published Crocodile family tree mapped: New light shed on croc evolution
(via sciencedaily.com) Original source Around 250 million years ago, 700 species of reptiles closely related to the modern-day crocodile roamed the earth, now new research reveals how a complex interplay between climate change, species competition and habitat can help explain why just 23 species of crocodile survive today.
Published Aging societies more vulnerable to collapse
(via sciencedaily.com) Original source Societies and political structures, like the humans they serve, appear to become more fragile as they age, according to an analysis of hundreds of pre-modern societies. A new study, which holds implications for the modern world, provides the first quantitative support for the theory that the resilience of political states decreases over time.
Published Antarctica's ancient ice sheets foreshadow dynamic changes in Earth's future
(via sciencedaily.com) Original source Identifying how and why Antarctica's major ice sheets behaved the way they did in the early Miocene could help inform understanding of the sheets' behavior under a warming climate. Together, the ice sheets lock a volume of water equivalent to more than 50 meters of sea level rise and influence ocean currents that affect marine food webs and regional climates. Their fate has profound consequences for life nearly everywhere on Earth.
Published Decoding past climates through dripstones
(via sciencedaily.com) Original source A recent study demonstrates how dripstones can be crucial for reconstructing past climates. The new approach can provide a detailed picture of the climate around early human occupations in South Africa.
Published 600 years of tree rings reveal climate risks in California
(via sciencedaily.com) Original source The San Joaquin Valley in California has experienced vast variability in climate extremes, with droughts and floods that were more severe and lasted longer than what has been seen in the modern record, according to a new study of 600 years of tree rings from the valley.
Published Landscape dynamics determine the evolution of biodiversity on Earth
(via sciencedaily.com) Original source A landmark study into the geological timescale distribution of sediment and nutrients over 500 million years shows that species biodiversity on Earth is driven by landscape dynamics.
Published Deoxygenation levels similar to today's played a major role in marine extinctions during major past climate change event
(via sciencedaily.com) Original source Scientists have made a surprising discovery that sheds new light on the role that oceanic deoxygenation (anoxia) played in one of the most devastating extinction events in Earth's history. Their finding has implications for current day ecosystems -- and serves as a warning that marine environments are likely more fragile than apparent. New research, published today in leading international journal Nature Geosciences, suggests that oceanic anoxia played an important role in ecosystem disruption and extinctions in marine environments during the Triassic--Jurassic mass extinction, a major extinction event that occurred around 200 million years ago. Surprisingly however, the study shows that the global extent of euxinia (an extreme form of de-oxygenated conditions) was similar to the present day.