One of Earth’s Largest Ocean Circulation Systems Slows to Unprecedented Rates

Nature Geoscience, February 25 After a long and relatively stable period, one of Earth’s largest ocean circulation systems — the Atlantic Meridional Overturning Circulation (AMOC) —started weakening during the early 19th century; followed by a second, more rapid, decline in the mid-20th century. Over the past few months, according to this study the AMOC has […]

Melting of Southern European Glacier is Faster Than in any Previous Warm Phase During the Last 2000 Years

The Cryosphere, March 3 The response of glaciers in southern European mountain ranges, such as the Pyrenees, to previous warm periods in the Holocene (an epoch covering the previous 12,000 years) has not been well documented. This study concludes that the Monte Perdido Glacier, located in the Central Pyrenees of northeastern Spain, lost significant mass […]

Projections of Greenland Ice Sheet Loss by 2100 Using CMIP6 Models for IPCC AR6

The Cryosphere, February 26 The contribution of Greenland to global sea level rise by 2100 can be as low as 20 mm, and as high as 160 mm (16 cm), depending on whether we follow low or high emissions pathways during the rest of this century; based on modeling from the new “ISMIP6” effort.  This work is based […]

Major Infrastructure Damage in Northwestern Greenland due to Accelerating Glacier Melt

Journal of Glaciology, February 17 In northwestern Greenland, rapid increases in meltwater from Qaanaaq Glacier resulted in two abnormally intense floods during the summers of 2015 and 2016.  The high discharge associated with the 2015 flood, over three times higher than normal from this glacier, came from intense melt caused by warm temperatures and strong […]

Accelerating Future Ice Loss for Svalbard Glaciers

Journal of Glaciology, February 17 Although several southern glaciers on Svalbard have retreated significantly in recent decades, the amount of ice overall has remained the same or shown very slight gains through 2018.  However, over the next forty years the average mass of Svalbard glaciers is anticipated to enter a phase of accelerating decline. This pattern […]

Experts Estimate of Carbon Emissions from Subsea Permafrost

Environmental Research Letters, December 22 Emissions from subsea permafrost – existing in near-coastal waters, mostly inundated at the end of the last Ice Age – long have comprised a question mark for global carbon budgets.  This expert assessment, with 32 co-authors estimated the total amount of subsea permafrost as containing 560 Gt carbon in organic […]

Catastrophic Indian Flood Appears Caused by Landslide, Not Glacier Collapse

Preliminary analysis of satellite images reveals that the massive, catastrophic floods in the Chamoli region of northern India last weekend could be the result of a large landslide. The slab – made of ice and rock – was 500 m across at the top and 150 m thick. The huge mass came crashing down the […]

Increased Outburst Flood Hazard in Peru from Climate Warming and Glacier Retreat

Nature, February 4 Over the past 140 years, the Cordillera Blanca region of the Peruvian Andes has warmed by 1°C, with 95% of that warming attributed to human emissions. This warming has triggered a dramatic acceleration in the retreat of the Palcaraju Glacier, with its meltwater causing expansion of Lake Palcacocha at the glacier’s base. […]

Massive Glacier in East Antarctica Shows Signs of Vulnerability

The Cryosphere, February 11 The massive Denman Glacier in East Antarctica, a 19 km-wide stream of ice that flows over the deepest undersea canyon of the continent, holds 1.5m of sea-level rise and is beginning to show signs of instability; potentially in response to the warming ocean at its base. During the past 50 years, […]

New Evidence of a Freshwater Arctic Ocean Covered by Thick Ice

Nature, February 3 During the two most recent ice ages, the Arctic Ocean was almost completely isolated from the rest of the world’s oceans by a thick ice shelf bordering the polar ice sheets covering the Arctic Ocean and parts of North America and northern Europe. This ice shelf cut off connections to the Atlantic […]

IPCC Projections of 2100 Sea-level Rise May Be Too Conservative

Ocean Science, February 2 Ice sheets and oceans take centuries to fully respond to changes in greenhouse gas concentrations and atmospheric temperatures, and the amount of sea level rise that will take place by 2100 is only the beginning of this response, which will take place over many centuries.  New models that correlate average global […]

Heightened Risk of Episodic Flooding and Water Shortages in the Himalayan Region

Nature Reviews Earth & Environment, February 2 Glacier melt and meltwater run-off in the Himalayan region will likely peak in the next few decades (around 2050 under a medium emissions scenario) and then decline as the glaciers shrink. Glaciers in nearly all this region have seen accelerating rates of ice loss for the past several […]

Mineral Phosphorus Accelerates Surface Melt on the Greenland Ice Sheet

Nature Communications, January 25 Glacier ice algae blooms on the surface of the Greenland Ice Sheet form a dark layer of microbial growth that increases the amount of solar radiation the ice absorbs, melting it more rapidly. This phenomenon largely occurs on the southwest portion of the ice sheet, and is responsible for up to […]

New Measurements Show Greater Warming of the Southern Ocean

Nature Communications, January 21 New analysis of a rare time series of temperature data, collected over 25 years aboard the French Antarctic station’s resupply vessel L’Astrolabe in the portion of the Southern Ocean that separates Australia and Antarctica, shows rapid ocean warming beneath the surface layers of water circling Antarctica, at a rate of 0.3°C warming per […]

Greenland’s Surface Also to Show Net Ice Loss at Global Temperatures Above ~2.5°C

Geophysical Research Letters, January 19 Greenland has been losing mass and contributing to sea-level rise since the 1980’s, according to most studies, with most of this loss occurring through calving of icebergs where glaciers running from the ice sheet meet the ocean. Melting of the surface of the ice sheet each summer however is largely offset […]

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