Science Advances, September 2 Summer sea ice minimums receive the most attention; but Arctic sea ice has been declining year-round, and new reconstructions place the 2018 winter maximum in the Bering Sea as the lowest in at least 5500 years. The 2018 and 2019 maximums were also 60-70% lower than the averages recorded since consistent […]
Journal of Glaciology, August 26 Up to 85% of the glaciers found in the Koshi River Basin could disappear by 2100 under the highest emission scenarios (RCP8.5). The Koshi River, a major tributary of the Ganges has a 50,000 km2 basin (the size of Costa Rica). Over 5% is covered by glaciers, and spreads across India, Nepal, […]
New maps collected under the floating tongue of Thwaites Glacier and further offshore reveal deep (> 1000 m) and wide (> 20,000 m) channels that guide warm ocean water under the ice, accelerating melt that eventually may lead to collapse. Thwaites, part of the West Antarctic Ice Sheet (WAIS) is the size of Great Britain, […]
Copernicus Atmosphere Monitoring Service, September 3 Arctic fire emissions – those directly caused by humans, as well as those from natural phenomena such as lightning strikes – already are one-third higher than the 2019 total, which itself broke the previous record. The CO2 released from these fires through the end of August totalled around 244 […]
Nature, August 26 Antarctic ice shelves – floating ice in contact with land ice – are both critical to maintaining ice sheet stability, and vulnerable to catastrophic fracturing from meltwater entering crevasses. Hydro-fracturing occurs when surface meltwater flows into and deepens pre-existing fractures, and is a potential mechanism driving sudden ice shelf collapse, as occurred with […]
The Cryosphere, August 28 Rain events on some portions of the Arctic Ocean have occurred nearly 4-6 days earlier for each recent decade, accelerating the onset of sea ice melt in the Pacific sector of the Arctic Ocean, and in the Eurasian Marginal seas above Siberia. This study combined limited field observations at Arctic coastal […]
Nature Climate Change, August 31 The global volume of glacier lakes increased 48% between 1990 and 2018, to 156.5 km3, a volume that would cover the country of Liechtenstein by a lake 1 km deep. Glacial lakes are bodies of water fed by a glacier’s meltwater, and subject to sudden outburst events that unexpectedly can […]
Nature Climate Change, August 31 The Greenland and Antarctic ice sheets have increased global sea level by 12.3 mm from 2007 and 2017, matching the most pessimistic predictions of the IPCC’s most recent assessment report (AR5). In particular, this study indicated that current models underestimate the contribution of ice sheet surface melt. The comparison […]
The Cryosphere Discussion/Review, August 14 A paper placed in open review notes that the cryosphere globally has lost a total of 28 trillion tonnes of ice (28,000 Gt) in the past 23 years, with a significant acceleration of mass loss since the year 2000. The largest losses have occurred to (in approximate order) Arctic sea […]
Nature, August 19 For the first time, researchers have been able to close the “sea-level budget” (relative sources of sea-level rise), gaining new insights on the drivers of observed global mean sea-level rise over the past century. By re-examining the contributions of glaciers, ice sheets, thermal expansion, and land water storage, this study was able […]
Nature Communications, August 24 The floating Shirase Ice Tongue (a long and narrow projection of ice, connected an ice basin about the size of the United Kingdom) in Queen Maud Land, East Antarctica, has revealed surprisingly high basal melt rates of 7 to 16 m per year. These rates equal or surpass the melting rate underneath […]
Nature, August 20 The Greenland Ice Sheet lost a record-breaking 532 (± 58 Gt) of ice in 2019, up around 200 Gt in the early 2000s, when it first became clear that the ice sheet was losing mass. The two GRACE satellite missions also provided new insights on the sensitivity of the Greenland Ice Sheet to climate-related changes in […]
Nature, Communications Earth & Environment, August 13 Acceleration of outlet glaciers from the Greenland ice sheet, not compensated by accumulation above makes it the current largest contributor to sea level rise. Through the 1980s and 1990s, losses through iceberg calving and melting were replaced by snowfall, keeping the ice sheet in balance. However, starting in […]
Nature Geoscience, August 10 Between 1994 and 2018, Antarctic ice shelves (floating ice connected to the land-based Antarctic ice sheet) lost close to 3960 Gt of ice. Many ice shelves bordering Antarctica lose mass through ocean-driven melting at their base. This study builds on previous work by using higher density satellite radar measurements, enabling far […]
Proceedings of the National Academy of Sciences, August 10 Under high emissions scenarios, northern hemisphere permafrost and peatlands will show a 30-50% greater contribution to warming than previously projected, with emissions impacts equivalent to 1% of all anthropogenic radiative forcing this century – and this takes into account both peatland carbon uptake and permafrost thaw […]