Nature Communications, December 15 New CMIP6 models developed for the sixth IPCC Assessment Report (AR6) show that surface melt from the Greenland Ice Sheet alone could contribute a total of 18 cm to sea-level rise under high emissions by 2100, nearly double the amount anticipated by CMIP5. These new models better include the Arctic’s greater […]

Frontier Earth Science, December 15 Measurements of carbon emissions (the greenhouse gases CO2 and methane) from a permafrost column sample found that still-frozen layers deeper in the soil produced measurable amounts of emissions, even prior to thaw.  This carbon release appears to arise from active microorganisms living in the frozen permafrost environment, adding to emissions […]

National Oceanic and Atmospheric Administration, December 7 This annual “Arctic Report Card” by NOAA detailed, among other things that as of this year, Arctic snow cover extent is decreasing at a rate of 3.7% per decade during May, with a much higher rate of loss (15% per decade) for June. Extreme temperatures this past spring […]

Water Resources Research, December 9 Rapidly increasing atmospheric temperatures in the Russian Arctic has led to increased extensive permafrost thaw in the region, with the depth of thaw going ever-deeper into lower permafrost layers.  This can cause the accelerated release of certain chemical substances, previously frozen in the permafrost, into neighboring waters such as Russia’s […]

Climate Dynamics, December 7 90% of the glaciers in the European Alps would completely disappear before 2100 under high emissions scenarios, while keeping global temperatures below 2°C would preserve at least 30% of these glaciers. With current emissions however, the Alps could see their mean annual summer temperature increase by up to 7°C by 2100 […]

Geophysical Research Letters, December 6   Under the new high emissions scenarios developed for IPCC AR6, accelerating sea ice loss will continue to take place both in summer and in winter across the Arctic, with the Barents Sea becoming the first sea-ice-free region in winter as well as summer before the end of the century. The models […]

Science Advances, November 27 Increasing discharge of freshwater from the melting ice of Greenland and other Arctic glaciers has not substantially changed the ocean currents circulating water between the tropical and polar regions of the North Atlantic Ocean over the past 30 years.  A remarkably stable region of polar currents in the eastern North Atlantic plays […]

Nature, November 25 From 20,000 to 9,000 years ago, at the end of the last Ice Age, rapid melt of the Northern Hemisphere ice sheets raised sea levels around Antarctica by 80-130 meters, which in turn drove the rapid retreat of the Antarctica Ice Sheet. These rapid sea-level changes triggered ice shelf loss and retreat of […]

Frontiers in Earth Science, November 26 Over the past 130 years, glaciers in Iceland have lost about 20 percent of their total ice (540 gigatons of ice mass). Nearly half of this glacier loss has occurred in the past 25 years. Most projections (in other studies of Iceland’s glaciers) indicate accelerating loss as temperatures rise, […]

The Cryosphere, December 1   Under emissions scenarios leading to 2°C of global warming and above, significant and rapid mass loss from the Greenland Ice Sheet would lock in several meters of unstoppable and irreversible global sea-level rise, persisting at least tens of thousands of years. The threshold of irreversibility could be reached in as […]

Nature Communications, November 25 Congestion of icebergs near an outlet glacier might lead to an increase in warmer water at the glacier’s base, causing greater calving of icebergs and even more ice loss, in a continuing feedback loop.  This modeling study found that underwater melting of icebergs in Greenland’s Sermilik fjord, at the end of the […]

Science, November 20 Over the past decade, sea levels have risen by an average of 4.8 millimeters per year, a rate much higher than the values estimated in the IPCC’s 2014 Fifth Assessment Report (AR5). This discrepancy suggests that the three main drivers of sea-level rise—thermal expansion of ocean water from global warming, melting glaciers […]

Nature Climate Change, November 23   The flow of heat from subtropical waters into the Nordic Seas and Arctic Ocean has increased over the past three decades. Monthly measurements since 1990 have shown that since 2001, the amount of heat has increased from 305 to 326 terawatts per month. This increase in ocean heat transport […]

Journal of Geophysical Research – Biogeosciences, October 15 Glacier runoff during the peak of Svalbard’s meltwater season contains lower levels of most nutrients (nitrates, carbonates, organic carbons and phosphates) than in the waters surrounding the polar archipelago.  This nutrient-poor runoff increases the absorption of CO2 from the atmosphere in the surrounding ocean, raising acidification and […]

The Cryosphere, November 12 Perhaps related to the above, a 1000-kilometer channel under the Petermann Glacier in northern Greenland may provide more rapid run-off from the ice sheet than previously appreciated.  Researchers realized that current maps of the bedrock under this portion of the ice sheet showed this channel as “blocked” at key points: due […]