Archives par mot-clé : Sea level

The Supermoon and SLR

by Kip Hansen, Apr 30, 2021 in WUWT

Dr. Judith Curry sent out a tweet about this article at The Conversation:  “This supermoon has a twist – expect flooding, but a lunar cycle is masking effects of sea level rise“.  The piece is written by Brian McNoldy, a Senior Research Associate, University of Miami and written in conjunction with Covering Climate Now — the climate news propaganda effort headed up by the Columbia Journalism Review and The Guardian.  The Conversation is a member of Covering Climate Now  and a search of their website shows they have published, so far, a total of 86 articles in cooperation with that organization.

McNoldy does a good job explaining what Lunar Nodal Cycle is and how it affects apparent local Relative Sea Level Rise

Bottom Line:

Miami, Florida has high tide flooding because much of Miami Beach (particularly) is built within a foot or two of normal high tides, and some portions are below normal high tides.  So, of course, Miami will experience tidal flooding again at these predicted higher tides.  For Miami’s real Sea Level story, see my earlier essay:  Miami’s Vice.

Follow the Science: Seas Rising 20 Times Slower than the Media Claim

by J. Taylor, Apr 13, 2021 in ClimateRealism

According to NASA and NOAA satellite instruments, sea level is rising at a mere 3 millimeters per year, which is a pace of just under one foot per century. (Note, the NASA/NOAA-reported 3.3 mm/year rise in Global Mean Sea Level includes a 0.3 mm “adjustment” that accounts for land rising as glaciers melt. The sea-level rise in relation to coastal shorelines is therefore 3.0 mm/year.) Moreover, the satellite measurements show no significant acceleration during recent decades in the pace of sea-level rise.

Given that seas are rising at a pace of merely one foot per century, which is little if any faster than the pace of sea-level rise throughout the global warming of the 1800s and 1900s, it is almost certain that seas will not rise 20 feet during the next 100 to 200 years. It is also almost certain that seas will not rise two feet during the next 20 years.

Subsidence In The Bangladesh Basin

by P. Homewood, Mach 26, 2021 in NotaLotofPeopleKnowThat

Absolute sea levels are rising by about 2mm a year, yet the land is subsiding by 2.2cm a year. A small part of this is due to isostasy, but most is evidently the result of “dewatering”, what we would call water extraction. (see here)

Whatever problems farmers in Bangladesh are having, it has nothing to do with climate change.

We’re Not Gonna Drown! Analyses Show COASTAL SEA LEVEL RISE Is Only 1.69 mm Per Year!

by P. Gosselin, March 23, 2021 in NoTricksZone

UPDATE: Sea level rise near the coasts where people actually live is found to be 1.69 mm/yr. But when crunching the data for the entire ocean, as Willis Eschenbach has shown, a figure of just 1.52 mm/year is computed. 

Hot shot data analyst Zoe Phin at her site examines sea level rise.

There she notes, “Climate alarmists are worried that the sea level is rising too fast and flooding is coming soon. You can find many data images like this on the net:”

Sea Level and the Jersey Shore

by Kip  Hansen, March 22, 2021 in WUWT

Dr. Judith Curry has been writing about Sea Levels and New Jersey [and here], spurred on by a request for an evaluation of the topic from the New Jersey Business & Industry Association(NJBIA).  The NJBIA is concerned because a study by a team of sea level researchers at Rutgers University has called for “draconian policies unsupported by science” that would “harm our economy today” by overreacting to “legitimate concerns about climate change, sea level rise, and flooding”.   Dr. Curry’s full report is titled: “Assessment of projected sea level rise scenarios for the New Jersey Coast”.

Dr. Curry’s CFAN report contains this summary:

The summary conclusions of the CFAN Review are:

—  The sea level projections provided by the Rutgers Report are substantially higher than those provided by the IPCC, which is generally regarded as the authoritative source for policy making. The sea level rise projections provided in the Rutgers Report, if taken at face value, could lead to premature decisions related to coastal adaptation that are unnecessarily expensive and disruptive.

—  Scenarios out to 2050 for sea level rise and hurricane activity should account for scenarios of variability in multi-decadal ocean circulation patterns.

—  Best practices in adapting to sea level rise use a framework suitable for decision making under deep uncertainty. The general approach of Dynamic Adaptive Policy Pathways is recommended for sea level rise adaptation on the New Jersey coast.

I wrote a piece here at WUWT a year ago, titled “Atlantic City:   I’ll meet you tonite…..”, prompted by the Governor of New Jersey’s executive order stating that  “New Jersey has set a goal of producing 100 percent clean energy by 2050.” and  “New Jersey will become the first state to require that builders take into account the impact of climate change, including rising sea levels, in order to win government approval for projects.”  The sea level rise part of this executive order was based on an earlier draft of  the same  study by researchers at Rutgers University.

False Alarm: IPCC Models Say A Warming Antarctica REDUCES Sea Levels -0.8 Of A Meter By 3000

by K. Richard, March 15, 2021 in NoTricksZone

The IPCC-endorsed anthropogenic global warming (AGW) paradigm finds a warming Antarctica results in more precipitation locked up as ice on the continent. This contributes to reducing sea levels: a -1.2 mm/year−1 mitigation of sea level rise over the next 80 years.

In the 4th IPCC report, Working Group 1 (the physical science) reported that as global temperatures rise,GCMs [models] indicate increasingly positive SMB for the Antarctic Ice Sheet as a whole because of greater accumulation.” This means that by 2100 Antarctica “would contribute 0.4 to 2.0 mm yr−1 of sea level fall.” Over the next 980 years, Antarctica’s ice accumulation will reduce sea levels by nearly a full meter (-0.8 m by 3000).

“Acceleration” in Sea-Level Rise Found to Be False – An artifact of Switching Satellites

by P. Homewood, Feb 27, 2021 in NotaLotofPeopleKnwoThat

One of the most common arguments climate alarmists make is that rate of sea-level rise is “accelerating” or rising faster every year.

Sea-level data reported from satellites indicate seas are rising approximately of 3.3 mm/year (See Figure 1). By contrast, tidal stations have recorded a rise of approximately 1 to 2 mm annually, a rate which is little changed over the century or so for which we have adequate records. Indeed, as reported in Climate at a Glance: Sea Level Rise,  the oldest tide gauge in the USA, in New York City, shows no acceleration at all going back to 1850.

Why the large difference?

The answer it turns out is simple. When NASA and NOAA launched new satellites, the data they produced wasn’t the same as the data recorded by earlier satellites.

Figure 2. NOAA sea level data, showing the trend of each of the full individual satellite records and the overall trend. SOURCE: NOAA Excel Spreadsheet

Full post here.

Munging The Sea Level Data

by W. Eschenbach, Feb 21, 2021 in WUWT

For more than a decade now, I’ve been wondering about a couple of questions.

First, why does the satellite-based sea-level data show that the sea level is rising so much faster than the rise measured at tidal stations on the coastlines around the world? Records from tidal stations show a rise on the order of a couple of mm per year, a rate which is little changed over the century or so for which we have adequate records. But the satellite record (Figure 1) shows a rise of 3.3 mm/year. Why the large difference?

Second, why does the satellite-based sea-level show such significant acceleration? As mentioned above, the sea-level records from tidal stations, which are much longer, show little or no acceleration. But the satellite record claims that the rate of sea-level rise is increasing by about a tenth of an mm per year. That amount of acceleration would double the rate of sea-level rise in about thirty years. Again, why the large difference?

To start with, here’s what the satellite data says, according to the University of Colorado Sea Level Research Group.


Alarmism Dies In The Maldives: 97% Of 186 Island Coasts Have Grown (59%) Or Not Changed (38%) Since 2005

by C. Rotter, Dec 22, 2020 in WUWT

Reposted from NoTricksZone

By Kenneth Richard on 21. December 2020

Despite sea level rise, a 2019 global analysis (Duvat, 2019) found 89% of 709 island coasts have been either stable or growing in size in recent decades. A new Maldives-only study (Duvat, 2020) finds rapid (>3 to >50%) coastal growth in 110 of 186 Maldives islands from 2005 to 2016. Just 5 islands – 2.7% – actually contracted in size during this period.

Last year Dr. Virginie Duvat published a global assessment of how the Earth’s islands and atolls are faring against the ongoing challenge of sea level rise since satellite monitoring began in the 1980s.

Fortunately she found “no widespread sign of physical destabilization in the face of sea-level rise.” In fact, a) none of the 30 atolls analyzed lost land area, b) 88.6% of the 709 islands studied were either stable or increased in area, c) no island larger than 10 hectare (ha) decreased in size, and d) only 4 of 334 islands (1.2%) larger than 5 ha had decreased in size.

Browse: Home / 2020 / November / 20 / “Sinking” Maldives Clear Forests, Pave Beaches, To Construct Four New Airports For Future Tourism! “Sinking” Maldives Clear Forests, Pave Beaches, To Construct Four New Airports For Future Tourism!

by P. Gosselin, Nov 20, 2020 in NoTricksZone

Despite all the money-generating gloomy predictions of sinking islands, we reported in 2013 on how the Maldives was planning to build 30 new luxury hotels for future tourists.

The resort island of Landaa Giraavaru (Baa atoll), photo by: Frédéric DucarmeCC BY-SA 4.0.

Underwater in 7 years?

We recall how in 2012, the former President of the Maldives Islands, Mohamed, Nasheed said: “If carbon emissions continue at the rate they are climbing today, my country will be underwater in seven years.”

4 new airports!

Well, today the islands have not gone underwater and remains popular with tourists like never before. And to help with the job of ferrying the 1.7 million (2019) tourists to and from the resort islands, the Maldives have recently opened 4 new airports, according to German site Aero here!

Sea level rise and Antarctica

by Jim Steele, Nov 4, 2020 in WUWT

California’s and other American coastal towns are engaged in divisive arguments regards rising sea levels. Although observed sea levels rose less than 8 inches (0.08 inches per year) since 1900, some modelers forecast much bleaker futures. They predict a 2.4-foot rise for every 1°F rise above preindustrial temperatures, then accelerating to nearly 4.5 feet for every 1°F additional increase. Why a dramatic acceleration in sea level? It’s based primarily on dire models, typically presented to coastal planning commissions as ‘best science’, suggesting increasing ice instability and Antarctica ice sheet collapse. “Antarctica has the potential to contribute more than 3.3 feet of sea-level rise by 2100 and more than 49 feet by 2500.”

Those models have prompted some citizens to argue we must abandon the coasts via managed retreat. Others argue we should build better sea walls. But how high? Others rightfully ask, “how trustworthy are those models?” Model predictions of a collapsing Antarctica ice sheet are not based on observations.  Models of Antarctica’s catastrophic ice collapse are attempts to explain ancient sea levels such as the 30-foot higher levels 120,000 years ago.

There are good reasons toquestion catastrophic models. For one, away from the coast Antarctica’s surface temperatures average −70 °F. Antarctica’s extremely cold surfacesrequire global warming to increase many, many times more before surface glaciers could ever melt. For another, although greenhouse theory predicts increasing CO2  concentrations will raise temperatures, greenhouse theory also predicts added CO2  has a cooling effect on Antarctica (Wijngaarden & Happer 2020, Schmithüsen 2015).


New Climate Report: Islands Not Losing Land, People To Sea-Level Rise

by J. Taylor, Oct 19, 2020 in ClimateChangeDispatch

A new study posted at documents that most small islands are growing, not losing land to sea-level rise, and island nations are attracting growing populations rather than shedding climate refugees.

The new climate summary drives a stake into the heart of alarmist assertions that climate change and rising seas are threatening island nations and their populations.

Objective measurements show that islands and atolls are growing in size, not disappearing under rising seas.

Rising seas bring sand and sediment, which build up coastal shorelines and are more than keeping pace with rising waters.

Also, coral, as living organisms growing near sea level, build up their height along with the rising sea.

For example, climate activists often claim the island nation of Tuvalu is shrinking due to rising seas and spawning climate refugees.

However, a recent peer-reviewed study found eight out of Tuvalu’s nine coral atolls have grown in size during recent decades, and three-fourths of Tuvalu’s 101 reef islands have similarly grown in size.

Also, Tuvalu’s population is consistently growing, not declining, with 20% more people living on Tuvalu now than 30 years ago. Tuvalu’s population has doubled since 1970.

Additional peer-reviewed studies (see here, here, and here) confirm the same processes are allowing – and will continue to allow – other Pacific islands to keep up with rising seas.

For example, 30 years ago, the Canberra Times claimed all 1196 islands that comprise the Maldives could be completely underwater by now.

Not only are all 1196 islands still there, but the Maldives population has doubled during the past 20 years.

People are flocking to the Maldives islands, not fleeing them. The Maldives are absorbing political refugees, not spawning climate refugees.

To read the full summary, see Climate at a Glance: Islands and Sea Level Rise.

Claim: Sea level rise from ice sheets track worst-case climate change scenario

by University of Leeds, September 1, 2020 in WUWT/Nature

Ice sheets in Greenland and Antarctica whose melting rates are rapidly increasing have raised the global sea level by 1.8cm since the 1990s, and are matching the Intergovernmental Panel on Climate Change’s worst-case climate warming scenarios.

So far, global sea levels have increased in the most part through a mechanism called thermal expansion, which means that volume of seawater expands as it gets warmer. But in the last five years, ice melt from the ice sheets and mountain glaciers has overtaken global warming as the main cause of rising sea levels.

Dr Ruth Mottram, study co-author and climate researcher at the Danish Meteorological Institute, said: “It is not only Antarctica and Greenland that are causing the water to rise. In recent years, thousands of smaller glaciers have begun to melt or disappear altogether, as we saw with the glacier Ok in Iceland, which was declared “dead” in 2014. This means that melting of ice has now taken over as the main contributor of sea level rise. “


Further information

The study, “Ice-sheet losses track high-end sea-level rise projections,” is published today (31 August) in Nature Climate Change.

View towards Icefjord in Ilulissat. Easy hiking route to the famous Kangia glacier in Greenland. The Ilulissat Icefjord seen from the viewpoint. Declared a UNESCO World Heritage Site in 2004. Photo taken in Greenland.

Satellite survey shows California’s sinking coastal hotspots

by Arizona State University, August 2, 2020 in WUWT

A majority of the world population lives on low lying lands near the sea, some of which are predicted to submerge by the end of the 21st century due to rising sea levels.

The most relevant quantity for assessing the impacts of sea-level change on these communities is the relative sea-level rise – the elevation change between the Earth’s surface height and sea surface height. For an observer standing on the coastland, relative sea-level rise is the net change in the sea level, which also includes the rise and fall of the land beneath observer’s feet.

Now, using precise measurements from state-of-the-art satellite-based interferometric synthetic aperture radar (InSAR) that can detect the land surface rise and fall with millimeter accuracy, an Arizona State University research team has, for the first time, tracked the entire California coast’s vertical land motion.

They’ve identified local hotspots of the sinking coast, in the cities of San Diego, Los Angeles, Santa Cruz and San Francisco, with a combined population of 4 to 8 million people exposed to rapid land subsidence, who will be at a higher flooding risk during the decades ahead of projected sea-level rise.

“We have ushered in a new era of coastal mapping at greater than 1,000 fold higher detail and resolution than ever before,” said Manoochehr Shirzaei, who is the principal investigator of the NASA-funded project. “The unprecedented detail and submillimeter accuracy resolved in our vertical land motion dataset can transform the understanding of natural and anthropogenic changes in relative sea-level and associated hazards.”

The results were published in this week’s issue of Science Advances (DOI link here).

NOAA Bureaucrats Falsely Claim ‘Extraordinary’ Sea Level Rise

by H.S. Burnett, July 18, 2020 in ClimateRealism

The National Oceanic and Atmospheric Administration, which relies on perpetuation of the Climate Delusion to maintain high funding, is falsely claiming there has been “extraordinary” sea level rise since 2000. Fox News and other media outlets are devoting substantial attention to the assertion by NOAA bureaucrats. However, there is simply nothing extraordinary about recent sea level rise.

According to Fox News, NOAA claims “Communities in coastal areas of the U.S. saw record-setting high-tide flooding last year, part of a trend of rising seas … [and an] ‘extraordinary’ rise in high-tide flooding since 2000.”

“Damaging floods that decades ago happened only during a storm now happen more regularly, even without severe weather,” Nicole LeBoeuf, acting assistant administrator for NOAA’s National Ocean Service, told reporters in a conference call.

Even if high-tide flooding has increased in recent years, natural factors are the primary cause.

As detailed in Climate at a Glance: Sea Level Rise: Data shows global sea level has been rising at a relatively steady pace of approximately one foot per century since at least the mid-1800s, which was long before coal power plants and SUVs. Moreover, the United Nations Intergovernmental Panel on Climate Change (IPCC) confirms here has been no significant recent acceleration.

Global sea level has risen approximately 400 feet since the beginning of the end of the most recent ice age—approximately 20,000 years ago. The rate of sea level rise has risen and fallen at various times since then, slowing and increasing on the order of tens, hundreds, and thousands of years over the past 20,000 years. All of that variance had  nothing to do with human activities. Indeed, as NASA reports, sea level always rises between ice ages as ice sheets retreat. During the last interglacial period between ice ages, seas were four to six meters higher than we are experiencing today….

New Studies Suggests Sea Levels Are Lower Today Than They Were Even During The Little Ice Age

by K. Richard, June 18, 2020 in NoTricksZone

Coastal history analyses increasingly suggest sea levels are lower today than at any time in the last 7000 years – even lower than the 1600s to 1800s.

Recently we compared cartology from the 17th to 19th centuries to direct aerial images of coastal positions today. Rather surprisingly, there seemed to be more land area below sea level a few hundred years ago.

For example, an 1802 nautical map of New York City and Long Island shows there may have been more open waters in this region during the Little Ice Age than in 2019.


Image Source:

Shoreline analysis from India also suggests the coasts were further inland during the 1600s than they are today (Mörner, 2017).

Study: As Sea Levels Rise, Island ‘Drowning’ Is Not Inevitable

by A. Williams, June12, 2020 in ClimateChangeDispatch

Coral reef islands across the world could naturally adapt to survive the impact of rising sea levels, according to new research.

The increased flooding caused by the changing global climate has been predicted to render such communities – where sandy or gravel islands sit on top of coral reef platforms – uninhabitable within decades.

However, an international study led by the University of Plymouth (UK) suggests that perceived fate is far from a foregone conclusion.

The research, published in Science Advances, for the first time uses numerical modeling of island morphology alongside physical model experiments to simulate how reef islands – which provide the only habitable land in atoll nations – can respond when sea levels rise.

Pacific Island states will not longer play the patsies for the climate alarmists

by P. Homewood, May 27, 2020 in NotaLotofpeopleKnowThat

The science is settled. The time for debate is over. It’s actually better than we thought. The Pacific islands are not sinking under rising sea levels, in fact, the peer-reviewed science shows the exact opposite, the majority of low lying islands are either stable or increasing in size — something even ABC FactCheck was forced to concede.

Nevertheless, this has not stopped climate alarmists led by the Portuguese socialist and UN General Secretary Guterres from denying the peer-reviewed science and exploiting Pacific Island nations, by using them as patsies to peddle fear and misinformation with discredited claims of ”sinking islands”.

And so far, the Pacific islanders have been happy to play along; perhaps driven by a cargo-cult mentality, believing if they utter the magic words ”climate change” and pose for the international media forlornly staring out over the sea, that they might be rewarded with cash handouts from the UN Green Global Climate fund.

But that was all before the Wuhan Flu.

Sea Level Rise Is Accelerating (If You Ignore Pre 1970 Data!)

by P. Homewood, February 19, 2020 in NotaLotofPeopleKnowThat

This has to go down as one of the most fraudulent climate studies yet!

Want to know how sea level in your area is changing due to global warming and other factors? Our ‘report cards’ can help. Updated by the Virginia Institute of Marine Science each year as annual tide-gauge data become available, they display recent sea-level trends and project sea-level height to the year 2050 for 32 localities along the U.S. East, Gulf, West, and Alaskan coasts.

Report Card Components

Our report cards have 3 components: the 2050 projection, recent trends in the rates of sea-level change, and an explanation of processes affecting sea level at each locality.

The annotated chart below, using the latest data from Norfolk, Virginia, briefly explains the data and statistical approaches we use in our 2050 projections. Visit an individual locality for details on all its report-card components. You can also compare sea-level trends, projections and processes among localities and by region. For full technical details, read our report.

Jakarta is not an Exemplar of Sea Level Rise

by K. Hansen, January 25, 2020 in WUWT

Ted Nordhaus has an excellent article in the Wall Street Journal titled “Ignore the Fake Climate Debate”.

[  It may or may not be pay-walled for you — if it is, try searching the title in your search engine and use the link provided by Google/Bing/whatever — it may let you in or see here. ]


Jakarta, Indonesia, is not an exemplar of rising sea levels    

 Jakarta is a good proxy for many of the problems that Asian cities are having with sea levels — relative sea levels.   Is Relative Sea Level a problem specific to Asian cities?  No, but it is a common problem to Asian mega-cities as can be seen in this figure:

North Atlantic Sea Levels Have Been Falling At A Rate Of 7.1 mm/yr Since 2004…In Tandem With 2°C Cooling

by K. Richard/Chafik et al. 2019, January 20, 2020 in NoTricksZone

Rapid cooling in the North Atlantic has reversed regional sea level changes and has apparently spread to the Greenland ice sheet

Image Source: Chafik et al. (2019)

Despite stressing global sea level rise is worrisome and due to anthropogenic warming, Chafik et al. (2019) report a distinct cooling trend in the North Atlantic that coincides with a transition to falling regional sea levels since 2004.

19 Papers Published In 2019 Affirm Sea Levels Were METERS Higher Than Today 4-8 Thousand Years Ago

by K. Richard, January 16, 2020 in NoTricksZone

The onslaught of paleoclimate evidence for warmer-than-now Mid-Holocene climates – when the Earth’s sea levels were meters higher than they are today –  stormed through 2019.

There were 107 scientific papers published this past year indicating today’s warmth isn’t even close to being unusual or unprecedented when compared to the climates of the last centuries to millennia.

As illustrated below, there were also 19 papers affirming today’s sea levels are among the lowest of the last ~8000 years.

This is added to the list of nearly 100 scientific papers published in the last handful of years indicating Mid-Holocene sea levels were multiple meters higher than they are today due to the much more extensive glacier and ice sheet melt occuring during these millennia.

A Geological Perspective on Sea Level Rise Acceleration

by David Middleton, December 9, 2019 in WUWT

There have been at least three recent peer-reviewed papers asserting an anthropogenic acceleration in the rate of sea level rise (SLR): Church & White, 2006 (CW06), Church & White, 2011 (CW11) and Nerem et al., 2018 (N18). N18 only covers the satellite era (since 1993) and might actually be correct, albeit irrelevant. The primary culprits in the SLR acceleration scam are CW06 and CW11. Two other recent peer-reviewed papers clearly shoot down the notion of a recent anthropogenic acceleration: Jevrejeva et al., 2008 (J08) and Jevrejeva et al., 2014 (J14). This post will focus on CW11 (updated through 2013) and J14.

J08 and J14 indicate that the acceleration, to the extent there is one, started 150-200 years ago, consistent with the end of neoglaciation and that a quasi-periodic fluctuation (~60-yr cycle) is present. CW06 and CW11 also note the 19th Century acceleration; but also assert a more recent acceleration, presumably due to anthropogenic global warming. This SLR acceleration is, at worst, innocuous.

Figure 1. Jevrejeva et al., 2014 (red) and Church & White, 2011 (green).

Cartology Affirms Relative Sea Levels Were Similar To Or HIGHER Than Now During The Little Ice Age

by K. Richard, December 5, 2019 in NoTricksZone

Surprisingly accurate nautical maps created the 17th to 19th centuries strongly suggest coastal land area in both hemispheres were quite similar to today’s. There is even evidence relative sea levels were higher than now back then.

Image Source:

Globally, coasts have grown since the 1980s

Between 1985 and 2015, satellite observations indicate the world’s coasts gained 13,565 km²  more land area than they had lost to the seas (Donchyts et al., 2016).

This means more coastal land area is above sea level today than in the 1980s.

This surprises scientists, as they “expected the coast would start to retreat due to sea level rise,” but instead they observed “coasts are growing all over the world.”