Archives par mot-clé : Melting

How to Scare and Deceive without Lying: JPL Cries Wolf about Polar Glacial Melt

by C. Beisner, Nov 6, 2020 in WUWT


Yesterday NASA’s Jet Propulsion Laboratory published “The Anatomy of Glacial Ice Loss.” For the most part it’s an interesting, though not particularly revolutionary, discussion of the various forces that add to and subtract from glacial ice. Nothing wrong with that.

But its authors took the opportunity to insert a poison pill, a little bit of fearmongering, in a video caption:

Did you catch that little trick? “Combined, the two regions also contain enough ice, that if it were to melt all at once, would raise sea levels by nearly 215 feet ….”

Well, yes, but at what rate is the ice from the two regions melting, and at what rate can we, with any confidence, predict they’ll continue to melt, and over what period of time?

There is absolutely no chance of their melting “all at once”—barring, I suppose, Earth’s collision with some enormous asteroid that sends Earth careening into the Sun!

So, how fast is the ice melting?

For Greenland, about 0.1% of its ice mass per decade—1 percent per century.

For Antarctica, about 0.0045% per decade—1% in 2,200 years.

Combined, those contribute to sea-level rise of about 1 mm per year, i.e., 3.94 inches per century.

(See “Lying with Statistics: The National Climate Assessment Falsely Hypes Ice Loss in Greenland and Antarctica.”)

So, if the actual rate is about 3.94 inches (0.3283 foot) per century, how long would it take to raise sea level by 215 feet? The answer: 215 ft. / 0.3283 ft. per century = 654.889 centuries, or 65,488.9 years.

Claim: Past evidence supports complete loss of Arctic sea-ice by 2035

by BRITISH ANTARCTIC SURVEY, August 3, 2020 in WUWT/Ch. Rotter


A new study, published this week in the journal Nature Climate Change, supports predictions that the Arctic could be free of sea ice by 2035.

BRITISH ANTARCTIC SURVEY

A new study, published this week in the journal Nature Climate Change, supports predictions that the Arctic could be free of sea ice by 2035.

High temperatures in the Arctic during the last interglacial – the warm period around 127,000 years ago – have puzzled scientists for decades. Now the UK Met Office’s Hadley Centre climate model has enabled an international team of researchers to compare Arctic sea ice conditions during the last interglacial with present day. Their findings are important for improving predictions of future sea ice change.

During spring and early summer, shallow pools of water form on the surface of Arctic sea-ice. These ‘melt ponds’ are important for how much sunlight is absorbed by the ice and how much is reflected back into space. The new Hadley Centre model is the UK’s most advanced physical representation of the Earth’s climate and a critical tool for climate research and incorporates sea-ice and melt ponds.

Using the model to look at Arctic sea ice during the last interglacial, the team concludes that the impact of intense springtime sunshine created many melt ponds, which played a crucial role in sea-ice melt. A simulation of the future using the same model indicates that the Arctic may become sea ice-free by 2035.

Joint lead author Dr Maria Vittoria Guarino, Earth System Modeller at British Antarctic Survey (BAS), says:

“High temperatures in the Arctic have puzzled scientists for decades. …

A snapshot of melting Arctic sea ice during the summer of 2018

by C. Rotter, July 30, 2020 in WUWT


 

IMAGE: THIS FIGURE SHOWS THE SEA ICE CONCENTRATION AND THICKNESS IN THE ARCTIC ON SEPTEMBER 23RD 2018. view more CREDIT: JUHI YADAV

As sea ice in the Arctic retreats further and melts faster every decade, scientists are racing to understand the vulnerabilities of one of the world’s most remote and unforgiving places. A study appearing July 29 in the journal Heliyon details the changes that occurred in the Arctic in September of 2018, a year when nearly 10 million kilometers of sea ice were lost over the course of the summer. Their findings give an overview at different timescales of how sea ice has receded over the 40 years of the satellite era and show how the summer’s extensive decline is linked to global atmospheric processes as far south as the tropics.

At the peak of its melting season, in July 2018, the Arctic was losing sea ice at a rate of 105,500 square kilometers per day–an area bigger than Iceland or the state of Kentucky. “On the ground, I am sure it would have looked like an excellent summer month in the Arctic, in general, but over the past four decades, September sea-ice loss has accelerated to a rate of 12.8% per decade and 82,300 square kilometers per year,” says co-author Avinash Kumar, a senior scientist at the National Centre for Polar and Ocean Research (NCPOR) in India.

Melting Glaciers Uncover Medieval Artefacts In Norway

by P. Homewood, April 16, 2020 in NotaLotofPeopleKnowThat


Melting glaciers in Norway have revealed ancient artefacts dropped by the side of a road more than 1,000 years ago.

Clothes, tools, equipment and animal bone have been found by a team at a lost mountain pass at Lendbreen in Norway’s mountainous region.

A haul of more than 100 artefacts at the site includes horseshoes, a wooden whisk, a walking stick, a wooden needle, a mitten and a small iron knife.

The team also found the frozen skull of an unlucky horse used to carry loads that did not make it over the ice.

The objects that were contained in ice reveal that the pass was used in the Iron Age, from around AD 300 until the 14th century.

Activity on the pass peaked around AD 1000 and declined after the black death in the 1300s, due as well to economic and climate factors.

The researchers say the melting of mountain glaciers due to climate change has revealed the historical objects, with many more to come.

https://www.dailymail.co.uk/sciencetech/article-8224817/Melting-ice-reveals-lost-Viking-mountain-path.html

 

Unfortunately neither the journalist nor the scientists seem to be capable of adding 2+2!

 

The existence of the Medieval Warm Period in Norway, followed by glacial advance in the Little Ice Age has been long known about, as HH Lamb wrote in 1982:

Denman Glacier–Latest Antarctic Meltdown Scare

by P. Homewood, March 24, 2020 in NotaLotofPeopleKnowThat


Scientists have found a new point of major vulnerability in the Antarctic ice sheet, in a region that already appears to be changing as the climate warms and has the potential to raise sea levels by nearly five feet over the long term.

Denman glacier, in East Antarctica, is a 12-mile-wide stream of ice that flows over the deepest undersea canyon in the entire ice sheet before spilling out into the ocean. That subsea trough is more than 2 miles deep, or double the average depth of the Grand Canyon. While there are far deeper trenches in the open ocean, such as the Marianas Trench, in this case the extreme undersea topography lies right on the outer fringe of the Antarctic continent — making it the “deepest continental point on Earth.”

In reality the scientists who wrote this study do not have a clue whether the retreat of the Denman is anything new or not, or whether the deep ocean temperatures are any warmer than before 1979. Or whether what they are observing is just a natural process.

 

We can then go on to explore sea level implications.

They claim that since 1979, 250 billion tonnes of ice has been lost, equivalent to 0.5mm of sea level rise. In other words, 1.3mm/C, hardly cataclysmic.

They then go on to talk about a potential loss of 540 trillion tonnes, raising sea levels by 5 feet. Yet at current rates, it would take 86400 years for this to occur!

As always with these sort of studies, the authors refuse to say how long all this will take to happen.

 

Comprehensive Data, Recent Studies In Top Journals: Antarctica Stable, Temps Falling, Ice Mass Growing!

by P. Gosselin, January 14, 2020 in NoTricksZone


The ice in Antarctica, how is it doing? Is it melting, is it growing? In the following we wishto present the latest literature on the subject. There is a lot to report.

Fasten your seat belt, there’s a lot to cover.

Let’s start with the temperature development because along with snowfall, this is the most important control factor for Antarctic inland ice.

At NoTricksZone, Kirye shows ten coastal stations of Antarctica. None have been warming over the past 10 years. An example follows:

 

And here’s the temperature development of the entire Antarctic according to UAH and RSS satellite measurements (from Climate4You, via NoTricksZone):

Greenland Ice sheet Meltdown Scare–Except It’s Not True

by P.  Homewood,  August 1, 2019 in NotaLotofPeopleKnowThat


The same heat dome that roasted Europe and broke national temperature records in five countries last week has shifted to Greenland, where it is causing one of the biggest melt events ever observed on the fragile ice sheet.

By some measures, the ice melt is more extreme than during a benchmark record event in July 2012, according to scientists analyzing the latest data. During that event, about 98 percent of the ice sheet experienced some surface melting, speeding up the process of shedding ice into the ocean.

The fate of Greenland’s ice sheet is of critical importance to every coastal resident in the world, since Greenland is already the biggest contributor to modern-day sea level rise. The pace and extent of Greenland ice melt will help determine how high sea levels climb and how quickly….

The Danish Meteorological Institute tweeted that more than half the ice sheet experienced some degree of melting on Tuesday, according to a computer model simulation, which made it the “highest this year by some distance.”

And there is no mention of the fact that the ice sheet grew substantially last year, and also the year before:

The simple fact is that the Greenland ice sheet melts every summer, particularly when the sun shines. That’s what it does. And it grows back again in winter as the snow falls. Indeed, if it did not melt, it would carry on growing year after year.

Inevitably there are some days when the weather is warmer and sunnier than normal, and others when it is colder. To pick an odd day or two is ridiculous and dishonest scaremongering.

See also here and here