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 […]

Nature Geoscience commentary, September 28 More than half of 2020’s Arctic fires so far this year have occurred in ice-rich permafrost. Formerly thought to be “fire resistant”, these ecosystems also contain the most carbon-rich soils in the Arctic, and are increasingly vulnerable to burning. The thawing, drying, and burning of ice-rich permafrost can considerably increase […]

Nature, September 30 Between 2000-2018, the Greenland Ice Sheet lost ice mass at the rate of 6100 billion tons of ice per century, exceeding the maximum rates at the end of the last Ice Age (the Holocene) 12,000 years ago, at 6000 billion tons/century. Under high-emissions scenarios, Greenland could lose up to 35,900 billion tonnes […]

Journal of Glaciology, Sept 23 Glacier mass loss has doubled in the Tian Shan mountains of eastern Central Asia, known as the region’s “Water Towers”.  This accelerated mass loss, in the glacierized Karlik range of the Tian Shan, between 2000-2015 as compared to 1972-2000 is associated with “dramatic” regional warming; and directly impacts water resources […]

Nature Communications, September 16 Under high emissions scenarios, additional permafrost thaw would drastically increase mercury concentrations in the Yukon River.  This could cause Yukon fish stocks to exceed U.S. EPA health guidelines within the next 30 years; and annual permafrost mercury emissions to the atmosphere would also increase, and be comparable to current global human […]

Science Advances, September 23 Under moderate and high emissions scenarios, the discharge of vast amounts of meltwater from the Antarctic Ice Sheet into the Southern Ocean could affect ocean currents and regional/global climate patterns due to impacts on the overturning ocean circulation.  The faster the ice sheet melts, the more cold freshwater flows into the […]

The Cryosphere, September 17 Sea-level rise from the Greenland and Antarctic ice sheets alone could be 39 cm higher by 2100 than previously estimated under high emissions scenarios. These new estimates come from a large international effort comprising more than 30 different institutions and 60 leading ocean, climate and ice-sheet scientists; and are based on […]

Nature, September 23 The rate and scale of ice loss from Antarctica will increase as temperatures exceed 2°C, according to new modeling from the Potsdam Institute.  At global warming up to 2°C above pre-industrial, Antarctica would lose enough ice mass to increase global sea-levels by 1.3 m per each degree of warming.  From 2°C to […]