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 […]

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 […]

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 […]

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 […]

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 […]

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 […]

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, 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. […]

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 […]

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; […]

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 […]

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% […]

Nature Communications, October 12   Past abrupt warming periods in the Arctic were related to near-complete disappearance of glaciers in the tropical Andes up to around 4,700 meters.  Arctic warming caused changes in ocean currents that then altered inter-hemispheric heat distribution: weakening the South American summer monsoons, as reflected in sediment records of Andean lakes […]

Nature, October 5 Dust carried by winds from the Middle East and Africa and deposited on snow is now the leading factor in snow melt at higher elevations (above 4000 m) in Central Asia and the Himalayan Plateau, playing a much bigger role on water resources than previously documented. Below 4000 m, the deposition of […]

Environmental Research Letters, October 7   The Arctic Ocean will reach an essentially ice-free state year-round (i.e., fully navigable) under the new high emissions scenarios developed for IPCC AR6.  This ice-free state will occur once global temperatures average 4.5°C above pre-industrial, which occurs well before 2100 in nearly all these new emissions scenarios based on […]