Future sea level rise from the ice sheets

[Trakar]

An expert judgement assessment of future sea level rise from the ice sheets
J. L. Bamber1
W. P. Aspinall2

Abstract

A major gap in predictive capability concerning the future evolution of the ice sheets was identified in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change. As a consequence, it has been suggested that the AR4 estimates of future sea-level rise from this source may have been underestimated. Various approaches for addressing this problem have been tried, including semi-empirical models and conceptual studies. Here, we report a formalized pooling of expert views on uncertainties in future ice-sheet contributions using a structured elicitation approach. We find that the median estimate of such contributions is 29 cm—substantially larger than in the AR4—while the upper 95th percentile value is 84 cm, implying a conceivable risk of a sea-level rise of greater than a metre by 2100. On the critical question of whether recent ice-sheet behaviour is due to variability in the ice sheet–climate system or reflects a long-term trend, expert opinion is shown to be both very uncertain and undecided.

(the paper has just been released, if anyone is interested I will see if I can find an open-source link for it, or at least provide a few more details in excerpt form from the pay-walled journal paper.)

 

[waltky]

Granny got Uncle Ferd an' possum puttin' pontoons onna side o' the trailer...

Global Warming Report: By End of Century, Sea Will Rise 0.66 Feet--Or 6.6 Feet
March 6, 2013 – An Obama administration-commissioned report predicts that because of climate change the global sea level will rise somewhere between 0.66 feet and 6.6 feet by the year 2100, citing a "lack of knowledge" as the reason for such a wide range of levels.

“Projecting future rates of sea level rise is challenging,” states a draft report released in January by a federal advisory committee appointed by the Commerce Department and the National Oceanic and Atmospheric Administration (NOAA), a federal agency. “Even the most sophisticated climate models, which explicitly represent Earth’s physical processes, cannot simulate recent rapid changes in ice sheet dynamics, and thus tend to underestimate sea level rise,” states the report by the National Climate Assessment and Development Advisory Committee.

Nevertheless, the committee predicts that the “future scenarios” of sea level rise “ranges from 0.66 feet to 6.6 feet in 2100.” “Higher or lower amounts of sea level rise are considered implausible by 2100,” the committee said. The U.S. Commerce Department created the National Climate Assessment and Development Advisory Committee in December 2010. In May 2011, National Oceanic and Atmospheric Administration Administrator Jane Lubchenco was named to its governing panel.

The committee was charged with developing a new National Climate Assessment report, following up on two previous reports published in 2000 and 2009. In January, the advisory committee released an 1,146-page draft report, available to the public to review and comment. In the draft report, the committee warns the “sea level is rising and is expected to continue to rise.” The report also contends that the impact of Hurricane Sandy was made worse by global warming. “The storm’s strength and resulting impact was certainly increased by the fact that the waters of the Atlantic Ocean near the coast were roughly 5 [degrees] F above normal and that the region’s coastline is experiencing sea level rise as a result of a warming climate,” it said.

In predicting where the global sea level will be in the next hundred years the committee said it cannot narrow its range due to “lack of knowledge.” “Lack of knowledge about the ice sheets and their behavior is the primary reason that projections of global sea level rise includes such a wide range of plausible future conditions,” they said. Though studies on the ice sheets in Greenland and Antarctica are ongoing and inconclusive, the committee said “cities, roads, railways, ports, airports, oil and gas facilities, and water supplies” are all vulnerable to climate change. “Sea level rise is not just a problem of the future,” the committee said, “but is already impacting coastal communities such as Charleston, South Carolina, and Olympia Drive in South Puget Sound through flooding during high tides and impacts on coastal roads.”

Source

 

[Old Rocks]

The climate modelers have been bitten bad in the area of prediction. In 2000, these 'alarmists' were predicting an ice free Artice Ocean for 2100. Right now, it looks as if we will see that before 2020, possibly even in the next two years. "The Storms of our Grandchildren" seem to have arrived a bit early. We are poking a rather large beast with a stick, and have little idea of what the results will be.

 

[CrusaderFrank]

Ipcc=joke

 

[waltky]

Caribbean showin' signs of sea level rise...

Encroaching sea already a threat in Caribbean
May 7,`13 -- The old coastal road in this fishing village at the eastern edge of Grenada sits under a couple of feet of murky saltwater, which regularly surges past a hastily-erected breakwater of truck tires and bundles of driftwood intended to hold back the Atlantic Ocean.

For Desmond Augustin and other fishermen living along the shorelines of the southern Caribbean island, there's nothing theoretical about the threat of rising sea levels. "The sea will take this whole place down," Augustin said as he stood on the stump of one of the uprooted palm trees that line the shallows off his village of tin-roofed shacks built on stilts. "There's not a lot we can do about it except move higher up." The people along this vulnerable stretch of eastern Grenada have been watching the sea eat away at their shoreline in recent decades, a result of destructive practices such as the extraction of sand for construction and ferocious storm surges made worse by climate change, according to researchers with the U.S.-based Nature Conservancy, who have helped locals map the extent of coastal erosion.

Dozens of families are now thinking about relocating to new apartments built on a hillside about a 10-minute walk from their source of livelihood, a tough sell for hardy Caribbean fishing families who see beachfront living as a virtual birthright. If climate change impact predictions come true, scientists and a growing number of government officials worry that this stressed swath of Grenada could preview what's to come for many other areas in the Caribbean, where 70 percent of the population live in coastal settlements. In fact, a 2007 report by the Nobel Prize-winning Intergovernmental Panel on Climate Change said the devastation wreaked on Grenada by 2004's Hurricane Ivan "is a powerful illustration of the reality of small-island vulnerability." The hurricane killed 28 people, caused damage twice the nation's gross domestic product, damaged 90 percent of the housing stock and hotel rooms and shrank an economy that had been growing nearly 6 percent a year, according to the climate scientists' report.

Storms and beach erosion have long shaped the geography of coastal environments, but rising sea levels and surge from more intense storms are expected to dramatically transform shorelines in coming decades, bringing enormous economic and social costs, experts say. The tourism-dependent Caribbean is thought to be one of the globe's most vulnerable regions. "It's a massive threat to the economies of these islands," said Owen Day, a marine biologist with the Caribsave Partnership, a nonprofit group based in Barbados that is spearheading adaptation efforts. "I would say the region's coastal areas will be very severely impacted in the next 50 to 100 years." Scientists and computer models estimate that global sea levels could rise by at least 1 meter (nearly 3.3 feet) by 2100, as warmer water expands and ice sheets melt in Greenland and Antarctica. Global sea levels have risen an average of 3 centimeters (1.18 inches) a decade since 1993, according to many climate scientists, although the effect can be amplified in different areas by topography and other factors.

In the 15 nations that make up the Caribbean Community bloc, that could mean the displacement of 110,000 people and the loss of some 150 multimillion- dollar tourist resorts, according to a modeling analysis prepared by Caribsave for the United Nations Development Program and other organizations. Twenty-one of 64 regional airports could be inundated. About 5 percent of land area in the Bahamas and 2 percent of Antigua & Barbuda could be lost. Factoring in surge from more intense storms means a greater percentage of the regional population and infrastructure will be at risk.

MORE

 

[whitehall]

An expert judgement assessment of future sea level rise from the ice sheets
J. L. Bamber1
W. P. Aspinall2

Abstract

A major gap in predictive capability concerning the future evolution of the ice sheets was identified in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change. As a consequence, it has been suggested that the AR4 estimates of future sea-level rise from this source may have been underestimated. Various approaches for addressing this problem have been tried, including semi-empirical models and conceptual studies. Here, we report a formalized pooling of expert views on uncertainties in future ice-sheet contributions using a structured elicitation approach. We find that the median estimate of such contributions is 29 cm—substantially larger than in the AR4—while the upper 95th percentile value is 84 cm, implying a conceivable risk of a sea-level rise of greater than a metre by 2100. On the critical question of whether recent ice-sheet behaviour is due to variability in the ice sheet–climate system or reflects a long-term trend, expert opinion is shown to be both very uncertain and undecided.

(the paper has just been released, if anyone is interested I will see if I can find an open-source link for it, or at least provide a few more details in excerpt form from the pay-walled journal paper.)

While the freaking a-hole scientists, who need those federal grants to keep them in their Lexus cars, are "formalizing, conceptualizing and estimizing, the rest of us are enjoying their geological good fortune in being born in a declining ice age. It's the sun stupid.

 

[Katzndogz]

Fill a glass half full of water. Drop in a few ice cubes. Carefully mark the water level. Wait for the ice cubes to melt. Check the water level.

Hint. It will be the same with melted ice cubes as it was with frozen ice cubes.

In other news, solar activity has caused the polar ice caps on Mars to all but disappear and in a few years they may disappear.

 

[Old Rocks]

Fill a glass half full of water. Drop in a few ice cubes. Carefully mark the water level. Wait for the ice cubes to melt. Check the water level.

Hint. It will be the same with melted ice cubes as it was with frozen ice cubes.

In other news, solar activity has caused the polar ice caps on Mars to all but disappear and in a few years they may disappear.

My, my, here is another dumb fuck that believes that the Greenland and Antarctic continents don't exist. There are thousands of feet of ice sitting above sea level on those continents, and it will raise the level of the sea as it melts.

 

[SSDD]

My, my, here is another dumb fuck that believes that the Greenland and Antarctic continents don't exist. There are thousands of feet of ice sitting above sea level on those continents, and it will raise the level of the sea as it melts.

And you believe that the ice sheets are melting in the face of overwhelming data to the contrary...simply because models that have been proven deficient for decades say that they are going to melt..

A 'Scientific' American article, Greenland Meltdown Driven by Collapse of Glaciers at Ocean Outlets, begins with the scary proclamation, “the ice sheet as a whole has lost some 36 billion metric tons of ice each year in recent years.” However, the New Zealand Climate Conversation Group calculates this amounts to an annual loss of only 0.00148% of the Greenland ice cap and would require only 67,222 years to meltdown at that rate [if an ice age doesn't occur beforehand].
Furthermore, 'Scientific' American conveniently fails to point out

1. The authors of the study said in the abstract:

“Our results suggest that the ice mass changes in this sector were primarily caused by short-lived dynamic ice loss events rather than changes in the surface mass balance. This finding challenges predictions about the future response of the Greenland Ice Sheet to increasing global temperatures.”

2. This is normal behavior for ice caps since the last ice age

3. Meanwhile, the interior of Greenland is growing by 5.4 cm/yr.

Greenland Meltdown Driven by Collapse of Glaciers at Ocean Outlets [Slide Show]: Scientific American

According to an article published in Science, the thickness of the Greenland ice sheet as a whole has been growing at the rate of 5.4 cm/yr (following correction for isostatic uplift). The only areas thinning are selected coastal areas exposed to periodic warm ocean oscillations. This change is also consistent with the natural behavior of ice sheets.

Greenland warming of 1920?1930 and 1995?2005 - Chylek - 2006 - Geophysical Research Letters - Wiley Online Library

A paper published online yesterday in the Journal of Geophysical Research finds "the loss rate in southeast Greenland for the more recent period has become almost negligible, down from 109 ± 28 Gt/yr of just a few years ago. The rapid change in the nature of the regional ice mass in southeast and northwest Greenland, in the course of only several years, further reinforces the idea that the Greenland ice sheet mass balance is very vulnerable to regional climate conditions." Global warming allegedly due to greenhouse gases would not be expected to cause such regional interannual variability in Greenland ice loss, thus pointing to shifts in weather instead

Interannual variability of Greenland ice losses from satellite gravimetry - Chen - 2011 - Journal of Geophysical Research: Solid Earth (1978?2012) - Wiley Online Library

A new paper published in Nature finds from ice cores that Greenland was 8C warmer than the present during the last interglacial period from 130,000 to 115,000 years ago. The authors also find "only a modest ice-sheet response to the strong warming," during which the ice sheet was 130 meters lower than the present. Needless to say, no "tipping point" occurred when Greenland warmed by more than 2C, as claimed by climate alarmists.

Greenland ice cores reveal warm climate of the past

A new paper published in Climate of the Past reconstructs Greenland temperatures over the past 800 years and shows that reconstructed temperatures were higher in the 1930's and 1400's than at the end of the record in the year 2000. The paper also finds Greenland temperatures correlated to "solar-induced changes in atmospheric circulation patterns such as those produced by the North Atlantic Oscillation/Arctic Oscillation (NAO/AO)." The Medieval Warming Period 1000 years ago is not included in this 800 year reconstruction, but Greenland ice cores demonstrate that the Medieval, Roman, Minoan, Egyptian, and other unnamed warming periods were all warmer than modern Greenland temperatures.

CP - Abstract - On the origin of multidecadal to centennial Greenland temperature anomalies over the past 800 yr

A new paper from the 2011 Antarctic Science Symposium presents new ice core data from Greenland and finds that not even the southern portion of Greenland was ice-free during the Eemian period, despite temperatures much higher than the present (5°C or 9°F) lasting for 16,000 years (from 130,000 to 114,000 years ago). Meanwhile, alarmists such as Richard Alley (buddy of Michael Mann at Penn State) and James Hansen claim "The entire ice mass of Greenland will disappear from the world map if temperatures rise by as little as 2°C." Note global temperatures have recovered by a mere 0.7°C since the end of the Little Ice Age in 1850 and have been flat to declining since 1998.

https://events.icecube.wisc.edu/contributionDisplay.py?contribId=19&sessionId=7&confId=34

A paper published today in Quaternary Science Reviews examines fossilized plants at the edge of the Istorvet ice cap in East Greenland and determines the ice cap "was smaller than the present from AD 200 to AD 1025." The ice cap subsequently grew during the Little Ice Age [LIA] and then retreated to the present size significantly larger than was present during the Medieval & Roman warming periods.

ScienceDirect.com - Quaternary Science Reviews - Late Holocene expansion of Istorvet ice cap, Liverpool Land, east Greenland

According to a press release from the British Antarctic Survey, temperatures of the Antarctic peninsula were 1.3°C warmer than today 11,000 years ago. Examination of a graph from the paper [below] also indicates nearby sea surface temperatures were up to a remarkable 10°C warmer than the 1961-1990 mean 12,000 years ago as the Earth emerged from the last major ice age. The graph also indicates the Antarctic peninsula warmed at a much faster rate from 13,000 to 12,000 years ago than over the past 1000 years. Greenhouse gases could not possibly explain this radical climate change, especially given the fact that there was little change in greenhouse gases during these periods and that infrared radiation from greenhouse gases cannot heat the oceans.

Ice core shows Antarctic Peninsula warming is nothing unusual ? The Register

A paper published last month in the journal Climate Dynamics finds that "The Antarctic sea ice extent (SIE) shows an increased trend during 1979–2009, with a trend rate of 1.36 ± 0.43% per decade. Ensemble empirical mode decomposition analysis shows that the rate of the increased trend has been accelerating in the past decade."

Sea ice trends in the Antarctic and their relationship to surface air temperature during 1979?2009 - Springer

A paper published today in The Cryosphere finds Antarctica has been gaining surface ice and snow accumulation over the past 150+ years, and finds acceleration in some areas noting, "a clear increase in accumulation of more than 10% has occurred in high Surface Mass Balance coastal regions and over the highest part of the East Antarctic ice divide since the 1960s." Furthermore, the paper notes, "Global climate models suggest that Antarctic snowfall should increase in a warming climate and mitigate rises in the sea level."

TC - Abstract - A synthesis of the Antarctic surface mass balance during the last 800 yr

And it could go on and on and on peer reviewed paper after peer reviewed paper demonstrating beyond any doubt that your fears simply do not reflect reality.