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Did early agriculture knock the climate off track?

During the last 2.5 million years, Earth’s climate has seen cycles of advancing and retreating glaciers over much of the Northern Hemisphere. We are currently in a warm, interglacial period — one that’s been prolonged by increases in atmospheric concentrations of greenhouse gases, such as carbon dioxide and methane. According to a new study in Nature, these high concentrations of greenhouse gases have disrupted the recent pattern of cycling in Earth’s climate and pushed back the next ice age. The study also suggests that human activity, beginning thousands of years ago with early agriculture and continuing through to the present day, has fueled the rise in greenhouse gas concentrations.

12 Dec 2018

Southern Ocean is absorbing less carbon

In the Southern Ocean surrounding Antarctica, complex and dynamic interactions among the atmosphere, cryosphere, and surface and deep ocean waters play an important role in climate. Although it covers only a quarter of Earth’s oceanic surface area, the Southern Ocean — with its cold temperatures and carbon-sucking algal blooms — has been estimated to take up 40 percent of anthropogenic carbon dioxide emissions. However, new data collected by a fleet of autonomous floating sensors show that the Southern Ocean is taking up significantly less carbon than scientists thought.

10 Dec 2018

Science by floats

The Southern Ocean Carbon and Climate Observations and Modeling project (SOCCOM) set out four years ago to study the Southern Ocean and its role and influence on global climate. The main mission of the project was to increase Southern Ocean observations, especially during the frigid winter months, to better understand climate change and biogeochemistry.

10 Dec 2018

New tool predicts probability of earthquake-triggered landslides

Landslides are the third-leading cause of death in earthquakes, after building collapses and tsunamis. Unlike tsunamis, however, which usually arrive minutes to hours after an earthquake, earthquake-triggered landslides tend to occur simultaneously with ground shaking, so a landslide warning system is not possible. But a new model that predicts where landslides may be triggered during earthquakes could help emergency aid and rescue efforts.

07 Dec 2018

Fats on Neolithic pottery pinpoint climate cooling event

About 8,200 years ago, right around the time that animals such as cows and sheep were first being domesticated in the Near East for meat and milk, the planet underwent a cooling event that lasted about 160 years. How this cold snap, known as the 8.2-kiloyear event, affected early farmers has long been a mystery, as archaeological evidence from the period of the cooler and drier climate has been scant. But new research investigating fatty residues preserved on scraps of pottery found at the UNESCO World Heritage site of Çatalhöyük in Turkey is offering some clues.

05 Dec 2018

Forecasting California's earthquake hazard

In California, scientists use a model called the Uniform California Earthquake Rupture Forecast (UCERF3) to assess earthquake hazards across the state based not on the physics of the state’s faults, but on history: By considering the historic record of earthquakes, including the location and severity of past quakes, UCERF3, the third version of the model, provides a hazard measure. “But those observations are limited, because we only have a few hundred years [of written earthquake records] in California,” says Greg Beroza, a seismologist at Stanford University. “In the long term, we have a small sample of the possible behavior of the system.” This means the resulting hazard assessments, relying on the relatively short historical earthquake record, may not accurately reflect earthquake potential across the state. So, scientists have long been trying to come up with physics-based models that show how particular faults might rupture without depending on historical records — and now, they have.

04 Dec 2018

Sulfides in thawing permafrost responsible for carbon dioxide release

After warming the bench since the Pleistocene, a key player in the Arctic carbon cycle is getting back in the game thanks to thawing permafrost. In a new study, researchers report that rising temperatures are freeing sulfide minerals previously bound within Arctic permafrost. These minerals are contributing to stream acidification and accelerated weathering of carbonates — and thus to the release of carbon dioxide into the atmosphere — at least in one part of northern Canada.

03 Dec 2018

Antarctic rift was active more recently than thought

Studying Antarctica’s geology is difficult because of the continent’s remote location and extreme weather, and because most of it is buried under kilometers of ice. More than 100 volcanoes hint at the White Continent’s fiery history, however. Scientists have long known that Antarctica was once split into two plates along the West Antarctic Rift system. A new study provides information about when this rift system was last active, and the findings have implications for calculating plate tectonic movements around the planet.

03 Dec 2018

Climate cooling a driver of Neanderthals' extinction

Neanderthals disappeared from Europe roughly 40,000 years ago, and scientists are still trying to figure out why. Did disease, climate change or competition with modern humans — or maybe a combination of all three — do them in? In a recent study, researchers offer new evidence from Eastern Europe that climate change was a major player in the Neanderthals’ disappearance.

30 Nov 2018

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