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Résultats pour:
arctique
There is increasing concern that the Atlantic Meridional Overturning Circulation (AMOC) may collapse this century with a disrupting societal impact on large parts of the world. Preliminary estimates of the probability of such an AMOC collapse have so far been based on conceptual models and statistical analyses of proxy data. Here, we provide observationally based estimates of such probabilities from reanalysis data. We first identify optimal observation regions of an AMOC collapse from a recent global climate model simulation. Salinity data near the southern boundary of the Atlantic turn out to be optimal to provide estimates of the time of the AMOC collapse in this model. Based on the reanalysis products, we next determine probability density functions of the AMOC collapse time. The collapse time is estimated between 2037-2064 (10-90% CI) with a mean of 2050 and the probability of an AMOC collapse before the year 2050 is estimated to be 59±17%.
A crucial system of ocean currents may already be on course to collapse, according to a new report, with alarming implications for sea level rise and global weather — leading temperatures to plunge dramatically in some regions and rise in others. Using exceptionally complex and expensive computing systems, scientists found a new way to detect an early warning signal for the collapse of these currents, according to the study published Friday in the journal Science Advances. And as the planet warms, there are already indications it is heading in this direction.
Ice-free summers inevitable even with sharp emissions cuts and likely to result in more extreme heatwaves and floods
Antarctica’s sea ice levels are plummeting as extreme weather events happen faster than scientists predicted
The sixth assessment report of the IPCC assessed that the Arctic is projected to be on average practically ice-free in September near mid-century under intermediate and high greenhouse gas emissions scenarios, though not under low emissions scenarios, based on simulations from the latest generation Coupled Model Intercomparison Project Phase 6 (CMIP6) models. Here we show, using an attribution analysis approach, that a dominant influence of greenhouse gas increases on Arctic sea ice area is detectable in three observational datasets in all months of the year, but is on average underestimated by CMIP6 models. By scaling models’ sea ice response to greenhouse gases to best match the observed trend in an approach validated in an imperfect model test, we project an ice-free Arctic in September under all scenarios considered. These results emphasize the profound impacts of greenhouse gas emissions on the Arctic, and demonstrate the importance of planning for and adapting to a seasonally ice-free Arctic in the near
Seafloor landforms reveal that ice sheets can collapse at 600 metres per day.
The Greenland Ice Sheet covers 1.7 million square kilometers (660,200 square miles) in the Arctic. If it melts entirely, global sea level would rise about 7 meters (23 feet), but scientists aren't sure how quickly the ice sheet could melt. Modeling tipping points, which are critical thresholds where a system behavior irreversibly changes, helps researchers find out when that melt might occur.
With the continent holding enough ice to raise sea levels by many metres if it was to melt, polar scientists are scrambling for answers
From the seemingly inexorable increase of carbon dioxide in the atmosphere to the rapid growth in green energy
Russian energy company Rosneft announced the discovery of a massive oil resource in the Pechora Sea with an estimated 82 million tons of oil. A drilling campaign in the Medynsko-Varandeysky area led to the discovery of the field. “During the tests, a free flow of oil was obtained with a maximum flow rate of 220 cubic meters a day,” the company’s statement read on Wednesday, noting that the “oil is light, low-sulfur, low viscosity.” According to Rosneft, the exploratory work in the Pechora Sea confirmed the "substantial oil potential of the Timan-Pechora province on the shelf and served as the foundation for continuing the study and development of the region."
We may lose up to three meters of coastline in the Arctic every year by 2100 if greenhouse gas emissions are not reduced, according to a study published in the journal Nature Climate Change. The authors also warn about bigger waves due to increasing temperatures, making the coastline very vulnerable to further losses due to erosion.
‘This event is completely unprecedented and upended our expectations about the Antarctic climate system,’ one expert said
The rapid collapses of two ice shelves on the Antarctic Peninsula over the past quarter-century were most likely triggered by the arrival of huge plumes of warm, moisture-laden air that created extreme conditions and destabilized the ice, researchers said Thursday.
Most marine-terminating glaciers in the Northern Hemisphere are shrinking; some have completely left the water.
The loss of its buttressing ice shelf could hasten the demise of the “Doomsday Glacier”
