Scientists finetune odds asteroid hitting
![scientists finetune odds asteroid hitting scientists finetune odds asteroid hitting](https://s1.cdn.autoevolution.com/images/news/chances-of-hazardous-asteroid-hitting-earth-are-higher-than-scientists-thought-167156-7.jpg)
If the Paris Agreement targets are to be met, there may be very few years left for policy makers to start cutting emissions. During the entire period, the mass loss concentrated in areas closest to warm, salty, subsurface, circumpolar deep water (CDW), that is, consistent with enhanced polar westerlies pushing CDW toward Antarctica to melt its floating ice shelves, destabilize the glaciers, and raise sea level. The contribution to sea-level rise from Antarctica averaged 3.6 ± 0.5 mm per decade with a cumulative 14.0 ± 2.0 mm since 1979, including 6.9 ± 0.6 mm from West Antarctica, 4.4 ± 0.9 mm from East Antarctica, and 2.5 ± 0.4 mm from the Peninsula (i.e., East Antarctica is a major participant in the mass loss). In 2009–2017, the mass loss was dominated by the Amundsen/Bellingshausen Sea sectors, in West Antarctica (159 ± 8 Gt/y), Wilkes Land, in East Antarctica (51 ± 13 Gt/y), and West and Northeast Peninsula (42 ± 5 Gt/y). We compare the results with a surface mass balance model to deduce the ice sheet mass balance.
![scientists finetune odds asteroid hitting scientists finetune odds asteroid hitting](https://awarenessact.com/wp-content/uploads/2021/08/shutterstock_126987932.jpg)
We use updated drainage inventory, ice thickness, and ice velocity data to calculate the grounding line ice discharge of 176 basins draining the Antarctic Ice Sheet from 1979 to 2017. We infer that southwest Greenland will become a major future contributor to sea level rise. The spatial pattern of accelerating mass changes reflects the geography of NAO-driven shifts in atmospheric forcing and the ice sheet’s sensitivity to that forcing. The negative phase of the NAO enhances summertime warming and insolation while reducing snowfall, especially in west Greenland, driving surface mass balance (SMB) more negative, as illustrated using the regional climate model MAR. The strongest accelerations tracked the phase of the North Atlantic Oscillation (NAO). Gravity Recovery and Climate Experiment (GRACE) and global positioning system (GPS) observations reveal that the spatial patterns of the sustained acceleration and the abrupt deceleration in mass loss are similar. In mid-2013, an abrupt reversal occurred, and very little net ice loss occurred in the next 12–18 months. From early 2003 to mid-2013, the total mass of ice in Greenland declined at a progressively increasing rate.