Current Models Underestimate Ice Loss from Largest Greenland Glaciers

Nature Communications, November 17   From 1880 to 2012, Greenland’s three largest outlet glaciers lost enough ice to increase global sea levels by around 8 mm. These three glaciers currently drain 12% of the ice sheet, and together contain enough ice to raise sea levels by another 1.3 meters. However, climate projections under high emissions […]

Increasing River Temperatures Trigger Arctic Sea-Ice Decline and Atmospheric Warming

Science Advances, November 6 Warmer river discharge waters into the Arctic Ocean contributed up to 10% of regional sea-ice loss from Arctic continental shelves between 1980 and 2015. Particularly notable, this injection of warm freshwater also increased sea-ice breakup in late spring and early summer. The decline of Arctic sea-ice causes a warmer Arctic Ocean […]

Past Climate Conditions Anticipates Sea Level From Ice Sheets and CO2 Stabilization

Science, November 6 The Pliocene Epoch (3-4 million years ago) is our best analogue for current rates of climate change. During this period, CO2 concentrations peaked at 427 ppm; and sea-level was about 17 m higher than today, implying a near-to-complete loss of the Greenland and West Antarctic Ice Sheets, as well as substantial portions […]

Widespread Sea-Ice Decline in Nordic Seas Associated with Past Extreme Greenland Warming

Proceedings of the National Academy of Sciences, November 9   During the last Ice Age (about 110 000 to 10 000 years ago), a number of abrupt climate warming events increased temperatures up to 16.5°C over the Greenland Ice Sheet over just a few decades. New analysis of ice and sediment cores shows that such […]

High Arctic Temperatures and Low Sea-Ice Levels Cause Heatwaves at Mid-Latitudes

Environmental Research Letters, October 12 As the Arctic rapidly warms, the temperature difference between that region and warmer lower latitudes decreases, resulting in a weakened polar jet stream (the ribbon of very fast winds that greatly influences mid-latitude weather). Changes in the shape of the polar jet stream over the past decade have allowed for […]

Potential Climate Sensitivity Above 5°C from Cloud Feedback Mechanisms

Nature Geoscience, October 26 Updated CMIP6 climate models (produced for the next IPCC assessment AR6) consider the radiative effects of clouds and may show higher values of warming for a doubling of CO2 in the atmosphere.  If these new estimates are borne out, the upper limit of warming for a doubling of CO2 would rise […]

Additional Global Warming Feedbacks from Decay of the Earth’s Cryosphere

Nature Communications, October 27   New climate modelling shows that feedbacks from cryosphere melt dynamics including loss of Arctic summer sea-ice, melting of the Greenland and West Antarctic Ice Sheets, and retreat of mountain glaciers could result in an additional 0.4°C of global temperature rise under 1.5°C emissions scenarios. This warming response from melting ice […]

A Closer Look at Greenland’s Ice Sheet Margins and Glacier Outlets

Journal of Geophysical Research – Earth Surface, October 27 Over the past three decades, the Greenland Ice Sheet ice transitioned from near balance to rapid mass loss, due to increasing temperatures in the atmosphere and ocean. For the outlet glaciers of Greenland, feeding into the oceans, multiple factors affect the behavior of individual glaciers and […]

Agricultural Irrigation in NW China Creates Unexpected Glacier Growth in Western Himalayas

The Cryosphere, September 24 While most glaciers are losing mass, the Kunlun Shan and Karakoram mountain range contains glaciers that are stable or growing due to increased snowfall, linked in this study to extensive agricultural irrigation in the Tamir and Junggar Basins.  Greater rates of evapotranspiration from plants in these irrigated lowlands lead to increases in […]

Reduced Biodiversity in the Arctic with Higher Sea Ice Loss

Nature Climate Change, October 27   If higher human greenhouse gas emissions continue, greater loss of Arctic sea ice will significantly reduce many species in the Arctic.  Lower sea ice coverage results in more light availability in these increasingly open-ocean conditions, favoring the growth of more southerly forms and even blooms of phytoplankton and zooplankton, […]

Arctic Sea Ice Building Stalls to Record Low for October

Arctic sea ice, normally growing rapidly at this time of year post-sundown, has stalled.  Extent is currently 1.2 million square kilometers lower than the 2012 record low season, which had recovered to 6.6 million square kilometers by this point in the fall season; 2019, the third-lowest summer extent, also saw an unusually low recovery path. […]

Warming of the Arctic Ocean and Nearby Seas

Global and Planetary Change, October 1 From 1982 to 2018, the Arctic Ocean and its surrounding seas have warmed by 1.3°C, with the greatest rate of warming occurring during the summer months, at +0.03°C/yr. The Greenland, Norwegian, Barents, and Chukchi Seas experienced the strongest warming due to incursion of warming waters from the mid-latitudes of […]

Worldwide Decline in Snow Accumulation and Duration

Environmental Research Letters, October 14   Snow cover and duration has declined worldwide over the past three decades due to the rise in global mean temperature.  Snowpack in the mid-latitudes and at lower altitudes — especially in the southern and south-eastern parts of the Himalayas; Iberian Peninsula; southern Andes; Drakensberg Range in South Africa; New Zealand; […]

Integrating Risks of Water Scarcity and Glacier Lake Outburst Floods in Peruvian Andes

Geoenvironmental Disasters, September 23 Towns and rural populations near the rapidly deglaciating Andes in Peru are threatened by both glacier lake outburst floods (GLOFs), and reduced water availability that will be heightened under a high emission scenario; however these two risks are rarely examined together.  This interdisciplinary study found glacier meltwater an important source of […]

Overlooked VOC Emissions from Thawing Arctic Permafrost May Increase Warming and Pollution

Environmental Research Letters, October 12 In thawing permafrost peatland soils studied in Finland, emissions of volatile organic compounds (VOCs, including alcohols, acids, ethers, and aldehydes) doubled when temperatures increased from 0 to 5°C.  Such VOCs help form tropospheric ozone, which contributes to both air pollution and global warming.  Under high emissions scenarios, more than 40% […]