Tag • #glaciers

chevron_right

Scientists call for greater study of glacier geoengineering options

news.movim.eu / TheGuardian · 3 days ago - 05:00

Report says serious research needed into risks and benefits as melting could cause devastating sea level rise

We need to seriously consider geoengineering projects to save our glaciers or face catastrophic sea level rise, scientists say in a report .

Antarctica and Greenland’s ice sheets are melting fast and even if we manage to reduce carbon emissions and limit global heating to 2C, it is not clear if that will be enough to prevent ice sheet collapse. But geoengineering glaciers may be a way to buy us vital time, the authors of the report argue.

chevron_right

Alaska’s top-heavy glaciers are approaching an irreversible tipping point

news.movim.eu / ArsTechnica · Sunday, 7 July - 11:07

Enlarge / Taku Glacier is one of many that begin in the Juneau Icefield. (credit: Mauricio Handler / Getty Images )

The melting of one of North America’s largest ice fields has accelerated and could soon reach an irreversible tipping point. That’s the conclusion of new research colleagues and I have published on the Juneau Icefield, which straddles the Alaska-Canada border near the Alaskan capital of Juneau.

In the summer of 2022, I skied across the flat, smooth, and white plateau of the icefield, accompanied by other researchers , sliding in the tracks of the person in front of me under a hot sun. From that plateau, around 40 huge, interconnected glaciers descend towards the sea, with hundreds of smaller glaciers on the mountain peaks all around.

Our work, now published in Nature Communications , has shown that Juneau is an example of a climate “feedback” in action: as temperatures are rising, less and less snow is remaining through the summer (technically: the “end-of-summer snowline” is rising). This in turn leads to ice being exposed to sunshine and higher temperatures, which means more melt, less snow, and so on.

Read 13 remaining paragraphs | Comments

chevron_right

Newly identified tipping point for ice sheets could mean greater sea level rise

news.movim.eu / TheGuardian · Tuesday, 25 June - 09:00

Small increase in temperature of intruding water could lead to very big increase in loss of ice, scientists say

A newly identified tipping point for the loss of ice sheets in Antarctica and elsewhere could mean future sea level rise is significantly higher than current projections.

A new study has examined how warming seawater intrudes between coastal ice sheets and the ground they rest on. The warm water melts cavities in the ice, allowing more water to flow in, expanding the cavities further in a feedback loop. This water then lubricates the collapse of ice into the ocean, pushing up sea levels.

chevron_right

East Coast has a giant offshore freshwater aquifer—how did it get there?

news.movim.eu / ArsTechnica · Monday, 20 May - 16:23

Image of a large boat with a tall tower at its center, and a crane in the rear. It is floating on a dark blue ocean and set in front of a white cloud.

Enlarge / An oceangoing scientific drilling vessel may be needed to figure out how huge undersea aquifers formed. (credit: Credit: IODP )

One-quarter of the world’s population is currently water-stressed , using up almost their entire fresh water supply each year. The UN predicts that by 2030, this will climb to two-thirds of the population .

Freshwater is perhaps the world’s most essential resource, but climate change is enhancing its scarcity. An unexpected source may have the potential to provide some relief: offshore aquifers, giant undersea bodies of rock or sediment that hold and transport freshwater. But researchers don’t know how the water gets there, a question that needs to be resolved if we want to understand how to manage the water stored in them.

For decades, scientists have known about an aquifer off the US East Coast. It stretches from Martha’s Vineyard to New Jersey and holds almost as much water as two Lake Ontarios. Research presented at the American Geophysical Union conference in December attempted to explain where the water came from—a key step in finding out where other undersea aquifers lie hidden around the world.

Read 25 remaining paragraphs | Comments

chevron_right

Bid to secure spot for glacier in Icelandic presidential race heats up

news.movim.eu / TheGuardian · Friday, 19 April - 15:51

Idea Angela Rawlings had a decade ago for Snæfellsjökull has snowballed into a full blown campaign with a team of 50 people

Standing in the shadow of Iceland’s Snæfellsjökull, – a 700,000-year-old glacier perched on a volcano and visible to half the country’s population on any given day – in 2010, Angela Rawlings was struck by an unconventional thought.

“It suddenly just came to me. What if the glacier was president?” said Rawlings. It was a seemingly unorthodox way to push forward a movement that was already swiftly advancing; Ecuador had enshrined legal rights for nature while Māori in New Zealand were working to secure legal personhood for the Whanganui River.

chevron_right

Andean alarm: climate crisis increases fears of glacial lake flood in Peru

news.movim.eu / TheGuardian · Tuesday, 26 March - 11:00

In 1941, thousands of people died in Huaraz when the natural dam on a lake above the city gave way. Now, melting glaciers are raising the chances of it happening again

• Photographs by Harriet Barber

Lake Palcacocha is high in the Cordillera Blanca range of the Peruvian Andes, sitting above the city of Huaraz at an altitude of about 4,500 metres. When the lake broke through the extensive moraines, or natural dams, holding it in place on 13 December 1941, it sent nearly 10m cubic metres of water and debris into the narrow valley towards the city, 1,500 metres below.

The result was one of the most devastating glacial lake outburst floods – or “GLOFs” – ever recorded. The force of the water altered the area’s geography for ever, and killed at least 1,800 people, and possibly as many as 5,000 .

chevron_right

Les crèmes solaires contaminent les neiges de l’Arctique

news.movim.eu / Numerama · Tuesday, 2 January, 2024 - 15:09

Plusieurs ingrédients issus des lotions corporelles, en particulier les filtres UV des crèmes solaires, ont été retrouvés dans les neiges du Svalbard, dans l'Arctique. Cela pourrait être particulièrement problématique à chaque fonte de ces neiges.

chevron_right

The Scientists Watching Their Life’s Work Disappear

news.movim.eu / TheNewYorkTimes · Thursday, 26 October, 2023 - 09:01

Some are stubborn optimists. Others struggle with despair. Their faces show the weight they carry as they witness the impact of climate change.

chevron_right

‘We’ve lost control’: what happens when the west Antarctic ice sheet melts? – podcast

news.movim.eu / TheGuardian · Tuesday, 24 October, 2023 - 04:00

Madeleine Finlay hears from environment editor Damian Carrington about why Antarctic ice may be melting even faster than we thought. He also reflects on the life and career of former environment editor John Vidal, whose death was announced last week