Archives par mot-clé : Greenland

climate-debate

Another Tipping Point Cancelled—Claims Of Runaway Greenland Ice Melt Overblown

by  Klimanachrichten, Oct 23,2023 in ClimateChangeDispatch

We have carefully read the definition of a “tipping point” as conveyed by the Potsdam Institute (PIK):

“It’s like a pencil that you push further and further over the edge of a table with your finger. First nothing happens – then it falls.” That’s what the PIK website says.

Nothing can bring the pencil back to the table except a failure of gravity, which is not conceivable. [emphasis, links added]

Then PIK lists various “elements” that are supposed to exhibit such behavior. To the Greenland Ice Sheet (GrIS), one finds:

There are indications that the tipping point, which leads to an almost complete loss of ice in the long term (about 10,000 years), could probably be reached at a global warming of just under 1.5°C (possible from 0.8°C global warming, at the latest at 3°C).“

Now there’s a paper on the subject that has appeared in “Nature“, which paints a different picture. It finds that even after a possibly “critical warming threshold” has been crossed, “the pencil does not fall down”:

We find several stable intermediate ice-sheet configurations … that return to the present-day state if the climate returns to present-day conditions.”

In addition, models often determine the warming in Greenland (the root of the evil) using the mean global warming rate and then apply an “Arctic amplification” factor to each warming to determine the temperature swing in Greenland.

The paper states:

Recently, it has been shown that the Arctic warms four times faster than the global average and thus substantially exceeds previous estimates and projections from climate models.

Arctic amplification of this magnitude would reduce the safe space for the GrIS substantially. However, surface temperatures around Greenland might not increase that severely in the future.”

Observations since 2000 now show that during this period, the warming of the Arctic is far from uniform:

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climate-debate

“RUN AWAY MELTING” IS AN IPCC EMBARRASSMENT; -23C (-9.4F) IN SWEDEN; + NORWEGIAN STATISTICS BUREAU COUNTERS GLOBAL WARMING HYSTERIA

by Cap Allon, Oct 23, 2023 in Electroverse

“RUN AWAY MELTING” IS AN IPCC EMBARRASSMENT

It’s been over 15-years since the release of the IPCC’s AR4 report which called for “run away melting” of Arctic sea ice. This bold proclamation, devised from a baseless extrapolating of a few ‘bad’ years, will be the ruin of the agency.

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See also: Greenland’s Tipping Point Cancelled? Claims Of A Runaway Melt Are Overblown

climate-debate

Greenland Icecap – 2023

By P. Homewood, Sep 2, 2023 in NotaLotofPeopleKnowThat

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As can be seen, the rate of loss in the last decade is similar to the 1930s, 50s and 60s. During the 1970s and 80s, Greenland’s climate grew much colder, and the ice mass loss almost stopped completely.

Significantly the rate of loss now is not accelerating, as you may have assumed from what the media have told you. On the contrary, the rate of loss has been slowing down since 2012.

The average annual loss between 2013 and 2022 was 184 Gt, which equates to 0.51mm sea level rise a year.

In short there is nothing alarming or unprecedented about the tiny amount of ice melt in Greenland.

climate-debate

Study: Northern Greenland Was Ice Free, Forested ~125k Years Ago, Adding 3 Meters To Sea Levels

by Diamond et al. 2021, Apr 27, 2023 in NoTricksZone

During the last interglacial (LIG) 127 to 119k years ago, when CO2 levels were said to be only 275 ppm, Greenland’s Camp Century surface was ice free, vegetated. Today this same site is buried under a 1.4 kilometers-high ice sheet.

The Arctic was sea ice free during the LIG (Diamond et al., 2021).

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climate-debate

Massive iceberg discharges during the last ice age had no impact on nearby Greenland, raising new questions about climate dynamics

by WUWT, Apr 24, 2023

CORVALLIS, Ore. – During the last ice age, massive icebergs periodically broke off from an ice sheet covering a large swath of North America and discharged rapidly melting ice into the North Atlantic Ocean around Greenland, triggering abrupt climate change impacts across the globe.

These sudden episodes, called Heinrich Events, occurred between 16,000 and 60,000 years ago. They altered the circulation of the world’s oceans, spurring cooling in the North Atlantic and impacting monsoon rainfall around the world.

But little was known about the events’ effect on nearby Greenland, which is thought to be very sensitive to events in the North Atlantic. A new study from Oregon State University researchers, just published in the journal Nature, provides a definitive answer.

“It turns out, nothing happened in Greenland. The temperature just stayed the same,” said the study’s lead author, Kaden Martin, a fourth-year doctoral candidate in OSU’s College of Earth, Ocean, and Atmospheric Sciences. “They had front-row seats to this action but didn’t see the show.”

Instead, the researchers found that these Heinrich events caused rapid warming in Antarctica, at the other end of the globe.

The researchers anticipated Greenland, in close proximity to the ice sheet, would have experienced some kind of cooling. To find that these Heinrich Events had no discernible impact on temperatures in Greenland is surprising and could have repercussions for scientists’ understanding of past climate dynamics, said study co-author Christo Buizert, an assistant professor in the College of Earth, Ocean, and Atmospheric Sciences.

“If anything, our findings raise more questions than answers,” said Buizert, a climate change specialist who uses ice cores from Greenland and Antarctica to reconstruct and understand the Earth’s climate history. “This really changes how we look at these massive events in the North Atlantic. It’s puzzling that far-flung Antarctica responds more strongly than nearby Greenland.”

Scientists drill and preserve ice cores to study past climate history through analysis of the dust and tiny air bubbles that have been trapped in the ice over time. Ice cores from Greenland and Antarctica provide important records of Earth’s atmospheric changes over hundreds of thousands of years.

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unclassified

Study Claims Ice Sheet Melt After Last Ice Age Faster Than Expected, Sans SUV

by E. Utter, Apt 11, 2023 in ClimateChangeDispatch

According to a recently released study, at the end of the last ice age, parts of an enormous ice sheet covering Eurasia retreated up to 2,000 feet per day.

That rate is the fastest measured to date, far exceeding what scientists previously believed to be the upper limits for ice sheet retreat. [emphasis, links added]

In the new study, lead author Christine Batchelor and her colleagues analyzed former beds of two major ice streams across the Norwegian continental ice shelf dating back 15,000 to 19,000 years ago.

Using ship-borne imagery, the team then calculated the rates of retreat by studying patterns of wavelike ridges along the seafloor.

They hypothesized that the “orderly” ridge patterns they observed may have been created as the front of the glacier bounced on the seafloor from daily tides.

Call me a skeptic, but this doesn’t sound to me like “settled science.”

Nonetheless, Batchelor and crew think the finding may shed light on how quickly ice in Greenland and Antarctica might melt — and raise global sea levels — in a warming world.

Batchelor stated: “If temperatures continue to rise, then we might have the ice being melted and thinned from above as well as from below, so that could kind of end up with a scenario that looks more similar to what we had [off] Norway after the last glaciation.”

According to a story in The Washington Post, Eric Rignot, a glaciologist who was not involved in the study, opined on it anyway, stating via email:

“This is not a model. This is real observation. And it is frankly scary. Even to me.” (Cue the voice of Elmer Fudd. “Yes, it is vewy, vewy, scawy, Rignot.” Not.

The only thing the study proves is that the Earth warmed quickly and dramatically eons ago— without any possible help from man.

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climate-debate

Media Regurgitate Nonsense About Greenland Ice Sheet And Sea Level Rise

by D. Burton, Apr 3, 2023 in ClimateChangeDispatch

CNBC and the Potsdam Institute (PIK) report that:

We’re halfway to a tipping point that would trigger 6 feet of sea-level rise from the melting of the Greenland Ice Sheet

PUBLISHED WED, MAR 29 202312:12 PM EDT By Catherine Clifford

KEY POINTS:

● Once people have cumulatively emitted approximately 1,000 gigatons of carbon in total, then the southern part of the Greenland Ice Sheet will melt eventually causing the sea level to rise by almost six feet.

● Once humans have cumulatively emitted approximately 2,500 gigatons of carbon in total, the whole Greenland Ice Sheet will eventually melt and the sea level rise would rise by 6.9 meters or 22.6 feet.

 

● And right now, now we are at approximately 500 gigatons of carbon emissions released.

Here’s the article.

Here’s the paper.

Like most things from PIK, this “study,” and this CNBC article, are nonsense. [emphasis, links added]

The best estimates are that since 1850, anthropogenic carbon emissions have totaled about 675 Gt of carbon (a/k/a PgC) (not 500).

Over that same period, the amount of CO2 in the atmosphere has increased by only about 135 ppmv CO2 = 287 PgC (gigatonnes carbon).

The difference is the amount removed from the atmosphere by natural negative feedbacks, such as absorption by the oceans, the greening of the Earth, and rock weathering.

(Aside: Petagram ≡ gigatonne ≡ Gt, and “PgC” means “petagram of carbon,” so 1 PgC = 1 Gt of carbon (GtC). 1 ppmv CO2 = 7.8024 Gt CO2 = 2.12940 PgC.)

Yet we’ve only gotten an estimated 1.02 to 1.27 °C of warming from all that CO2, and it’s beenaccompanied by negligible acceleration in sea-level trends:

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climate-debate

Greenland Temperatures 2020

by P. Homewood, June 12, 2021 in NotaLotofPeopleKnowThat

I mentioned a year ago that the reason for the deficit in ice mass increase during the winter and spring of 2020 was sustained cold and dry weather. (Conversely milder weather tends to bring snow). I also reported how the summer melt began much later than normal.

The Danish Meteorological Institute (DMI) have now published the official Greenland temperature for last year, bearing this out and showing how cold it really was:

 

image

Greenland Surface Mass Ice Balance 2019/20

http://polarportal.dk/en/greenland/surface-conditions/

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climate-debate

Greenland Temperatures Rose 1°C In 1994 … Since Then They Have Been ‘Relatively Constant’

by K. Richard, Feb 27, 2023 in NoTricksZone

A warming event that spans only one year, with decades of stable temperatures before and after, would not appear to align with rapidly rising human CO2 emissions or a gradually rising atmospheric CO2 concentration.

From 1958 to 2020, as CO2 rose from 320 ppm to 410 ppm, Greenland had a warming period of 1°C that lasted one year – 1994. Over the next 26 years (1994-2020) and spanning the years 1958 to 1993, there have been “relatively constant” temperatures across Greenland (Zhang et al., 2022).

These temperature trends appear to align much better with phases of the North Atlantic Oscillation (NAO), Greenland blocking indexes (GBI), and volcanism better than they do with any anthropogenic causal agents.

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unclassified

Greenland Mass Balance

by Andy May, Oct 25, 2022 in WUWT

The following is from Cap Allon’s excellent post here. We are all used to the mainstream media distorting climate science data and analysis, but he has uncovered a case that is beyond the pale. Consider this post a follow up to Dave Middleton’s post earlier the month.

Read on in Cap Allon’s words:

MSM OBFUSCATION

[Greenland’s ‘healthy’ melt season, was obscured across the mainstream media.]

CNN wrote the following in July 20 article: “The amount of ice that melted in Greenland between July 15 and 17 was enough to fill 7.2 million Olympic-sized swimming pools or cover the entire state of West Virginia with a foot of water.”

They even have a quote from cLiMaTe ScIeNtIsT Ted Scambos: “The northern melt this past week is not normal, looking at 30 to 40 years of climate averages. But melting has been on the increase, and this event was a spike in melt.”

CNN is screaming about this period of melting (circled below):

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climate-debate

There Is No Detectable Link Between Greenland’s Climate And Atmospheric CO2 Changes

by K. Richard, Sep 29, 2022 in NoTricksZone

Greenland’s climate changes are remarkably uncorrelated with climate model expectations and changes in atmospheric CO2.

When CO2 levels were in the mid-200s parts per million (11.7 to 4.5 thousand years ago) the Arctic and northern Greenland were 2-4°C warmer than now, ice margins were 80 km behind today’s, ice-free open water conditions prevailed, and Greenland warmed 10°C in just 60 years (Elnegaard Hansen et al., 2022).

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Past interglacial CO2 levels of only 280 ppm were associated with a “nearly ice free” Greenland and the presence of flora and fauna in subarctic terrestrial environments 1000 km northwards of where they can survive today, implying “at least 5°C higher temperatures” (Bennike and Böcher, 2021). Summer sea water temperatures were as much as “7-8°C higher than at present”.

better to know...?, climate-debate

New Study: Greenland ‘Must Have Been At Least 3°C Warmer’ Than Today During The Early Holocene

by K. Richard, Jul 4, 2022 in NoTricksZone

These much warmer Greenland temperatures imply that the elevation of the ice sheet was 400 meters lower than it is today from about 6,000 to 10,000 years ago.

Scientists (Westhoff et al., 2022) report that the two largest Greenland melt events in the last few hundred years occurred in 2012 and in 1889 CE – when atmospheric CO2 levels were still under 300 ppm.

The “melt events around the Holocene Climate Optimum were more intense and more frequent” than has been observed during the modern period. And the most prominent melt events of the last 10,000 years centered around the Medieval Warm Period, 986 CE.

Overall, the elevation of the Greenland ice sheet has grown by 0.4 km since the Early Holocene, as “summer temperatures must have been at least 3 ± 0.6°C warmer during the Early Holocene compared to today.”

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better to know...?, climate-debate

ON SATURDAY, GREENLAND’S SURFACE MASS BALANCE GAINED A RECORD-SMASHING 7 GIGATONS…

by Cap Allon, June 20, 2022 in Electroverse

If you want proof of mainstream media manipulation and agenda driving drivel, you need look no further than the “official” reporting of the Greenland ice sheet–the poster child for anthropogenic global warming. If today’s intensifying energy crisis wasn’t rooted in said obfuscations, all of this would be laughable.

Impressive surface mass balance (SMB) readings –a calculation to determine the ‘health’ of a glacier– have been posted across the Greenland ice sheet all season. But the cherry, at least for me, is taken by Saturday’s record-smashing 7 Gigaton GAIN–particularly when you consider the glacier should be losing mass at this time of year.

The MSM appears to love dumb, decontextualized headlines to advance their AGW narrative. So here’s one for them:

Greenland’s Recent SMB Gains Enough To Bury Central Park, New York City Under 7,833 Feet Of Ice… (it’s true, do the math).

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climate and geology

Holocene ice-free strait followed by dynamic Neoglacial fluctuations: Hornsund, Svalbard

by A. Osaka et al., Apr 25, 2022 in TheHolocene

Keywords

Abstract

The recession of the Hornbreen-Hambergbreen glaciers (Hornsund, Svalbard) will lead to the formation of a strait between the Greenland and Barents Seas within a few decades. We provide evidence for the earlier existence of this strait, in the Early–Middle Holocene and presumably since 1.3 ka cal. BP until glacier advance 0.7 ± 0.3 ka or earlier. Radiocarbon dating of mollusc shells from the ground moraines in the Hornbreen forefield indicate the existence of the marine environment at the contemporary glacierized head of Hornsund since 10.9 ka cal. BP or earlier due to glacier retreat. The gap in the radiocarbon dates between 3.9 and 1.3 ka cal. BP and the published results of 10Be exposure dating on Treskelen suggest the strait’s closure after glacier advance in the Neoglacial. Subsequent re-opening occurred around 1.3 ka cal. BP, but according to 10Be dates from Treskelen, the strait has again been closed since ca. 0.7 ± 0.3 ka or earlier. The oldest known surge of Hornbreen occurred around 1900. Analysis of Landsat satellite images, morphometric indicators characterizing the glacier frontal zones and previous studies indicate one surge of Hambergbreen (1957–1968) and five re-advances of Hornbreen in the 20th century (after 1936, between 1958 and 1962, in 1986–1990, 1998–1999, 2011). While the warmer Holocene intervals might be a benchmark for the effects of future climate change, glacier dynamics in post-Little Ice Age climate warming seems to be an analogue of glacier retreats and re-advances in the earlier periods of the Holocene.

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climate-debate, Cooling

New Analysis Of Greenland’s GISP2 Temperatures Expose Selection Bias In Paleo Reconstructions

by K. Richard, Mar 17, 2022 in NoTricksZone

Scientists admit that 3 different Greenland Summit (GISP2) temperature reconstruction “strategies” produce 3 different paleoclimate temperature results. The reconstructions chosen as the most “robust” are therefore the ones that align best with the authors’ presuppositions.

In a new study published in Quaternary Science Reviews scientists (Döring and Luenberger, 2022) report they reject a reconstruction of Greenland Summit temperatures that shows it has cooled ~4°C since Roman times (shown below as the red trend line, extended to 2000 C.E.).

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climate-debate, Cooling, Snow

Greenland Sees Significant Snow, Ice Mass Loss Slowdown Over Past Decade, Danish Data Show

by P. Gosselin, Nov 14, 2021 in NoTricksZone

Data from the Danish Polar Portal shows Greenland ice melt slowing significantly over past 10 years. Increasingly rapid mass loss is a myth. 

German climate site Die kalte Sonne here looks at whether Greenland is really melting faster or not in its 78th climate and energy video (3rd segment).

Satellite measurement has allowed accurate measurements over the years and so reliable trends are detectable.

Greenland has added mass since July

Over the past year, since September 2020, Greenland has seen a number of heavy snowfalls, as depicted by the solid blue line in the chart by the Danish polarportal.dk:

Image cropped: Die kalte Sonne.

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climate-debate

New Data Suggest Greenland’s Relative Sea Levels Were 6 Meters Higher 1,500-2,000 Years Ago

by K. Richard, Oct 28, 2021 in NoTricksZone

The discovery of whale bones and marine shells at ancient beach sites 32 to 36 meters above today’s shorelines have been dated to the Early to Middle Holocene. Beach ridges were still several meters higher than today during Roman and Medieval times.

The relative sea levels of the ancient past can be discerned by identifying the span of years marine shells were deposited on ancient beaches. Also, whales were as likely to wash up on shore thousands of years ago as they do today.

A new study (Souza et al., 2021) uses an alternative dating method to identify when beach ridge systems were still collection sites for sea shells along the west coast of Greenland (Disko Island). The authors find it “particularly interesting” that beach ridges were still elevated ~6 meters above modern sea levels less than 2,000 years ago, as previous studies have suggested the Disko Bay region’s sea levels should have fallen to below present sea level by this time.

The authors also determined the marine shells located 32 meters above present Disko Island shorelines can be dated to about 5,300 years ago. Whale carcasses collected at sites elevated 36 meters above modern have been dated to the Early Holocene.

The highest sea levels of the Holocene, or the Holocene Marine Limit, has been dated to ~9000 years ago. At that time deposits of sea shells on the southwest coast of Disko were as much as “~70 to 80 m above present sea level.”

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climate-debate

Greenland’s 2021 spring: more snow, less melt

by C. Rotter, July 14, 2021 in WUWTfromNSIDC

Surface melt and total melt-day area for the Greenland Ice Sheet at the end of the 2021 spring season was below the 1981 to 2010 average. Snowfall and rain (minus runoff) added mass to the ice sheet. As of June 20, total mass gain for the ice sheet since September 2020 was slightly above average. The spike from June 25 to June 27 will be discussed in later a post.

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climate-debate

Greenland Temperatures & The AMO

by P. Homewood, June 13, 2021 in NotaLotofPeopleKnowThat

It’s not new, but it’s worth going over it again.

We have seen how Greenland temperatures rose sharply in the 1920s, and remained at levels similar to the last decade until the 1960s, when they fell equally sharply. This change in climate is closely interlinked with the Atlantic Multidecadal Oscillation (AMO), which switches from cold to warm phase, and back again, roughly every 50 to 60 years:

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climate-debate

The anatomy of past abrupt warmings recorded in Greenland ice

by C. Rotter, Apr 19, 2021 in WUWT/Nature

New paper at Nature Communications

Abstract

Data availability and temporal resolution make it challenging to unravel the anatomy (duration and temporal phasing) of the Last Glacial abrupt climate changes. Here, we address these limitations by investigating the anatomy of abrupt changes using sub-decadal-scale records from Greenland ice cores. We highlight the absence of a systematic pattern in the anatomy of abrupt changes as recorded in different ice parameters. This diversity in the sequence of changes seen in ice-core data is also observed in climate parameters derived from numerical simulations which exhibit self-sustained abrupt variability arising from internal atmosphere-ice-ocean interactions. Our analysis of two ice cores shows that the diversity of abrupt warming transitions represents variability inherent to the climate system and not archive-specific noise. Our results hint that during these abrupt events, it may not be possible to infer statistically-robust leads and lags between the different components of the climate system because of their tight coupling.

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better to know...?, climate-debate

Greenland And Iceland Mean Winter Temperatures Continue Cooling Since Start Of The Century

by Kirye & Pierre, March 24, 2021 in NoTricksZone

The February 2021 data for Iceland and Greenland are available from the Japan Meteorological Agency (JMA), which means the latest meteorological DJF winter mean temperature can be computed.

Icelandic winters have cooled since 2001

We plotted the JMA data for three stations (the ones with sufficient data) in Iceland. Result: no warming over the past 18 winters!

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climate-debate

Danish Institute Data: Greenland Ice Melt Has Slowed Down Significantly Over Past Decade

by P. Gosselin, March 10, 2021 in NoTricksZone

The media and activists, among them a number of “Climate scientists”, have been declaring that Greenland ice melt has been accelerating.

Today the German Klimaschau climate news video reports, however, that this has not been the case over the recent years. All the recent talk about accelerating Greenland ice loss over the past years is false.

SMB on the rise

First a plot of Greenland’s surface mass balance SMB (blue curve below) shows that snow accumulation has occurred faster than snow and ice have melted over the past 35 years:

Chart: cropped from Klimaschau here. 

Though the annual SMB values declined from 1985 to 2012, the trend has rebounded since.

Loss through coastal discharge steady over the past 15 years

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better to know...?, climate-debate

Southeast Greenland Sea Surface Temperature 1° – 2°C Warmer In 1940 Than Today, New Study Shows

by P. Gosselin, Feb 14, 2021 in NoTricksZone

A team of Danish scientists led by David Wangner published a paper a year ago about the results of a Greenland sediment core from Skjoldungen Fjord, near the Thrym Glacier, which allowed sea surface temperatures to be reconstructed.

The core covers the past 200 years (1796–2013). The scientists find that the SST record compares well with other alkenone‐based reconstructions from SE‐Greenland and thus features regional shelf water variability.

Today some scientists like claiming the present is warmer than at any time in the past 1000 years and suggest the Greenland ice sheets are rapidly melting. But the results of the core reconstruction show that it was warmer in the past, some 80 years ago

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unclassified

Ocean forcing drives glacier retreat in Greenland

by M. Wood et al., Jan 01, 2021 in AAAS OPEN ACCESS

INTRODUCTION

The Greenland Ice Sheet has contributed substantially to sea-level rise over the past few decades. Since 1972, approximately two-thirds of the ice sheet’s contribution to sea-level rise resulted from increased glacier flux with the remaining one-third from anomalous surface melt (1). Before 2000, anomalous ice discharge was the dominant driver of mass loss, but in recent years, increasingly negative surface mass balance anomalies have contributed to a larger proportion of the total mass loss from the ice sheet (1). The acceleration in mass flux has been partially attributed to a warming of subsurface waters around Greenland near the end of the 1990s (2, 3) and increased runoff, resulting in enhanced water mixing and melt at glacier margins, destabilization of terminus regions (4, 5), ice front retreat (6, 7), and, in most cases, accelerated ice flow (8). The increase in flow speed, combined with enhanced surface melt, results in increased glacier thinning, which is conducive to further retreat (9). Other processes may have additionally contributed to the glacier retreat, e.g., increases in basal lubrication, melting of the ice mélange in front of glaciers, or weakening of glacier shear margins, but quantitative evidence about their impact has been limited (10–12).

The warming of subsurface waters at the turn of the 21st century was caused by the spreading of ocean heat from the subpolar gyre during a transition in the North Atlantic Oscillation (NAO) from a high positive phase to a low-to-negative phase (3). In this shift, the North Atlantic subpolar gyre expanded, enhancing ocean heat fluxes through the coastal Irminger and West Greenland currents, yielding warmer subsurface waters on the continental shelf of all seven major basins of Greenland (Fig. 1). Since 2010, the NAO has transitioned back to a more positive phase, yielding a relative cooling of the ocean waters, however, not sufficiently to bring back ocean heat fluxes to the levels of the 1990s (13).