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Categories: Mathematics: Puzzles, Paleontology: Climate

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     (via sciencedaily.com)     Original source 

Climate change will slow down deep overturning ocean circulation in the coming centuries. Using three dozen Earth system models, researchers have concluded that the Southern Meridional Overturning Circulation could completely shut down by 2300, causing disaster to the marine ecosystem on a large portion of the planet.

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A new study that reconstructs the history of sea level at the Bering Strait shows that the Bering Land Bridge connecting Asia to North America did not emerge until around 35,700 years ago, less than 10,000 years before the height of the last ice age (known as the Last Glacial Maximum). The findings indicate that the growth of the ice sheets -- and the resulting drop in sea level -- occurred surprisingly quickly and much later in the glacial cycle than previous studies had suggested.

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Scientists have discovered that the atmosphere contained far less CO2 than previously thought when forests emerged on our planet, the new study has important implications for understanding how land plants affect the climate.

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Spread across vast distances, the islands of the tropical Pacific Ocean are thought to have been populated by humans in two distinct migrations beginning approximately 3,330 years ago. The first followed a northern route out of what is today the Philippines and the second followed a southern route from Taiwan and New Guinea. People arrived on the islands between these routes -- now making up the Federated States of Micronesia -- about 1,000 years later. But a new finding by sea-level researchers suggests that the islands in Micronesia were possibly settled much earlier than supposed and that voyagers on the two routes may have interacted with one another.

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Fossilized microbial skins can give us a glimpse of how the climate was in the deep geological past. By discovering the 'missing link' between such fossil skins and the skins of living bacteria, researchers have greatly improved the accuracy of climate reconstructions and predictions.

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Climate change, rather than competition, played a key role in the ascendancy of dinosaurs through the Late Triassic and Early Jurassic periods.

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Sediment cores obtained from Eifel maar sites provide insight into the presence of large Ice Age mammals in Central Europe over the past 60,000 years: Overkill hypothesis not confirmed. Herds of megafauna, such as mammoth and bison, have roamed the prehistoric plains in what is today's Central Europe for several tens of thousands of years. As woodland expanded at the end of the last Ice Age, the numbers of these animals declined and by roughly 11,000 years ago, they had completely vanished from this region. Thus, the growth of forests was the main factor that determined the extinction of such megafauna in Central Europe.

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Changes in Earth's orbit that favored hotter conditions may have helped trigger a rapid global warming event 56 million years ago. Researchers found the shape of Earth's orbit, or eccentricity, and the wobble in its rotation, or precession, favored hotter conditions at the onset of the PETM and that these orbital configurations together may have played a role in triggering the event.

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By assessing so-called 'flavors' of El Nino events in past climate records and model simulations, researchers have a clearer picture of El Nino patterns over the past 12,000 years and are able to more accurately project future changes and impacts of this powerful force.

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Researchers have been studying the effects of the sudden decrease in global temperatures that occurred about 8,200 years ago, the so-called 8.2-kiloyear event, with the help of mineral deposits present in White Moon Cave in Northern California. New indications show that oscillations between extreme wetness and aridity in California were closely linked with the occurrence of wildfires. The researchers have concluded that such events are likely to become more common in the face of human-induced climate change.

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How is the weather changing as a consequence of global warming? Climate archives provide valuable glimpses into past climate changes, especially into the processes that drive our planet from one climate setting to the next. For humans and ecosystems, however, time spans of just weeks to years, which are the scope of weather events, are often most important. Using an newly developed and tested analytical method these two aspects have now been merged, and the impacts of the most recent global warming on seasonal temperature fluctuations have been described.

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Two-million-year-old DNA has been identified -- opening a 'game-changing' new chapter in the history of evolution. Microscopic fragments of environmental DNA were found in Ice Age sediment in northern Greenland. Using cutting-edge technology, researchers discovered the fragments are one million years older than the previous record for DNA sampled from a Siberian mammoth bone. The ancient DNA has been used to map a two-million-year-old ecosystem which weathered extreme climate change.

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A chance find of an unstudied Antarctic sediment core has led researchers to flip our understanding of how often ice ages occurred in Antarctica.

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The Southern Hemisphere is stormier than the Northern -- but no one knew why. A new study lays out the first concrete explanation for this phenomenon. Researchers found two major culprits: ocean circulation and the large mountain ranges in the Northern Hemisphere.

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Major ice streams can shut down, shifting rapid ice transport to other parts of the ice sheet, within a few thousand years. This was determined in reconstructions of two ice streams, based on ice-penetrating radar scans of the Greenland ice sheet.

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Years of research show that climate change signals are amplified in the Arctic, and that sea ice in this region is sensitive to increases in Arctic warming. Sea ice greatly modifies the exchanges of heat, momentum and mass between the atmosphere and the ocean. So, the timings of the sea ice melt and freeze onsets, as well as the length of the melt and freeze seasons, play a key role in the 'heat budget' of the atmosphere-ice-ocean system.

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Gamers who buy 'loot boxes' are up to two times more likely to gamble, shows new research.

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A new analysis of more than 20,000 trees on five continents shows that old-growth trees are more drought tolerant than younger trees in the forest canopy and may be better able to withstand future climate extremes. The findings highlight the importance of preserving the world's remaining old-growth forests, which are biodiversity strongholds that store vast amounts of planet-warming carbon, according to forest ecologists.

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Paleontologists say environmental DNA is not always helpful in identifying when animals like mammoths went extinct because genetic material found in sediment could have come from animals that died thousands of years earlier.

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The 1930s Dust Bowl affected heat extremes across much of North America and as far away as Europe and East Asia, according to new research. The study found that the extreme heating of the Great Plains triggered motions of air around the Northern Hemisphere in ways that suppressed cloud formation in some regions and contributed to record heat thousands of miles away.