Nature, January 4 Warming does not occur evenly across the world. Regional differences in temperature can influence the way the Earth sends its heat back into space and temporarily dampens the planet’s response to increasing emissions, therefore masking a warmer future. This feedback, not included in most models, has the potential to increase long-term estimates for […]

Science Advances, January 1   Warm Atlantic water flowing into dozens of Greenland’s deepest fjords nearly doubles the amount of ice loss by undercutting their outlet glaciers, accounting for about half of their melting and ice loss during the summer months.  The abrupt ∼1.9°C warming of sub-surface ocean waters around Greenland in 1998–2007 triggered widespread […]

Geophysical Research Letters, August 14   Since the 1970s, freshwater lakes in the Northern Hemisphere have been three times more likely to experience entirely ice-free winters, never freezing at all. Drawing less attention than Arctic sea ice loss, this shift – driven by warmer winters — carries major ecological, socio-economic, and cultural consequences. Projections show […]

Science Advances, December 16 Large tabular icebergs (with areas ≥ 3 km2) are one of the greatest sources of melting from the Antarctic Ice Sheet. Until now, studies struggled to accurately model these large icebergs, consistently misrepresenting their survival time or drifting trajectory. By including a new breakup mechanism applied to large icebergs, this study […]

Journal of Geophysical Research, December 15   A new revision of the UK Met Office HadCRUT5 dataset finds that global surface temperatures have actually risen 1.07°C since the industrial revolution, revising upwards their previous estimate of 0.91°C. This increased result arises in part from a better representation of Arctic warming, as well as from improved datasets […]

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 […]