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Sea Level Long-Term History

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Holocene Thermal Optimum and Sea Level. Cartology Affirms Relative Sea Levels Were The Same Or HIGHER Than Now During The Little Ice Age. 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.” Image Source(s): Donchyts et al., 2016 and BBC (press release) These recent trends would appear to be the opposite of what would be expected with modern global warming. Are relative sea levels lower now than during the 1800s? 1. Image Source: Antique Maps Online 2. Image Source: 3. 4.

Historical European Sea Level Records. Guest Essay by Kip Hansen I have been working on another sea level related essay and in the process stumbled upon a paper published in 1990 by the Permanent Service for Mean Sea Level (PSMSL). The title is: “On The Availability Of European Mean Sea Level Data by P.L. Woodworth, N.E. Spencer and G. I am not going to comment on the data itself, other than to include the PSMSL caveat that accompanies other papers of the late 1980s. Here are the graphs from the cited paper: I would be remiss if I did not include the caveat that PSMSL adds to papers of this period (1980s — early 1990s): What I see in the above is that Stockholm, an obvious outlier, has a strong downward trend — this is to be expected as Stockholm is in an area of positive (upward) Vertical Land Movement. I post these graphs for the sole purpose of bringing them into the current century where they can be seen and taken into account. 2.

Relative sea level is where the sea surface hits the land. 3. 4. 5. 6. 7. Author’s Comment: Holocene Sea Level Trends. By Paul Homewood There seems to be a general acceptance about overall sea level trends during the Holocene. There was naturally a very rapid rise in sea levels at the end of the ice age, until 6000 years ago, since when the rise has been much more gradual. Some research puts the rate of rise in the last 2000 years at 0.07mm/yr, and this reflects the fact that ice caps left over from the ice age are still melting, rather than that the world is warmer than before. However, the impression is often given that, until the 20thC, this rate of rise has been pretty steady.

HH Lamb looked carefully at many expert studies in his day, and wrote about the very significant fluctuations they found. 1) The most rapid phases [of sea level rise] were between 8000 and 5000 BC, and that the rise of general water level was effectively over by about 2000 BC, when it may have stood a metre or two higher than today. Like this: Like Loading... CO2 Control Knob? A 15-22°C Warmer Arctic With Sea Levels 25 m Higher When CO2 Ranged From 300-400 ppm. CO2 concentrations have risen from 310 ppm to 410 ppm since the 1930s. However, there has been no net change in Arctic or Greenland temperatures during these last 90 years. During the Pliocene, CO2 also ranged between about 300-400 ppm, but the Arctic was 15-22°C warmer and sea levels 25 meters higher than today.

Is CO2 really Earth’s “control knob”? Nearly ten years ago, the imagery of a CO2 “control knob” for climate was canonized in the journal Science. Image Source: Lacis et al., 2010 The CO2 concentration was said to determine – or control – Earth’s temperature. However, the scientific literature’s paleoclimate record does not provide fundamental support for this paradigm of a CO2-controlled climate. During the Ordovician, for example, CO2 concentrations reached 4,200 ppm – more than 10 times today’s levels. Image Source: Shuang et al., 2019 Arctic/Greenland warming? Image Source: Araźny et al., 2019 Image Source: Hanhijarvi et al., 2013 Image Source: Hanna et al., 2011.

Rapidly Fluctuating India Sea Levels Were 4 m Higher Than Today 6000 Years Ago, 1.5 m Higher 500 Years Ago. By Kenneth Richard on 18. July 2019 Scientists have found sea levels on India’s eastern coast were still 1-1.5 m higher than today as recently as 500 to 300 years ago and 3-4 m higher than today between 6000 to 4000 years ago. Seas rose and fell by multiple meters (-5 m to +3 m) within 1250 years until as recently as 4000 to 2000 years ago. A new paper (Loveson and Nigam, 2019) reveals sea levels were still rising at a rate of 2.2 meters per century between 8100 and 7200 years ago, reaching a highstand of 4 meters above today’s sea level 6050 years ago.

For the next several millennia sea levels rapidly rose and fell within a range 6 meters – between 4 meters above to -2 meters below present levels. A drop in sea level at one point reached an amplitude of -5 meters in just 1250 years (4350 to 3100 years ago) followed by 3 meters of sea level rise within 1200 years (3100 to 1900 years ago). Image Source: Loveson and Nigam, 2019 Image Source: BBC Image Source: Makwana et al., 2019.

'Reconstruction' begins of stone age lands lost to North Sea | Science. Lost at the bottom of the North Sea almost eight millennia ago, a vast land area between England and southern Scandinavia which was home to thousands of stone age settlers is about to be rediscovered. Marine experts, scientists and archaeologists have spent the past 15 years meticulously mapping thousands of kilometres under water in the hope of unearthing lost prehistoric tribes. On Wednesday a crew of British and Belgian scientists set off on their voyage across the North Sea to reconstruct the ancient Mesolithic landscape hidden beneath the waves for 7,500 years.

The area was submerged when thousands of cubic miles of sub-Arctic ice started to melt and sea levels began to rise. The ancient country, known as Doggerland, which could once have had great plains with rich soils, formed an important land bridge between Britain and northern Europe. It was long believed to have been hit by catastrophic flooding. Gaffney said they were praying for stable weather and good luck.

New Study Shows Sea Level Near In Western Pacific Was 0.4 Meters Higher 3600 Years Ago Than Today. Alarmists say that sea levels are rising rapidly, and unless we act now to take over the climate using the secret man-made CO2 reduction method, soon New York and even Cologne, Germany, will end up in water. At least that’s the alarmist scenario that the Truth Media like to tell us about. However, a number of studies and tide gauge data tell us a very different story. Hat-tip: reader Mary Brown. The latest study titled: Holocene sea-level change and evolution of a mixed coral reef and mangrove system at Iriomote Island, southwest Japan, by Yamano et al tells us that sea levels were more than 1 meter higher 5100 to 3600 years ago than they are today they, or 0.4 meters when corrected for tectonics.

The paper’s abstract follows: Exposed fossil microatolls and core samples from a coral reef and a mangrove forest at the Yutsun River mouth, Iriomote Island, southwest Japan, reveal the internal structure and temporal changes in the sedimentary processes of a mixed reef–mangrove system. New Paper: Widespread Collapse Of Ice Sheets ~5000 Years Ago Added 3-4 Meters To Rising Seas. During the Mid-Holocene, when CO2 concentrations were stable and low (270 ppm), Antarctica’s massive Ross Ice Shelf naturally collapsed, adding the meltwater equivalent of 3-4 meters to sea levels. Because CO2 concentrations changed very modestly during the pre-industrial Holocene (approximately ~25 ppm in 10,000 years), climate models that are predicated on the assumption that CO2 concentration changes drive ocean temperatures, ice sheet melt, and sea level rise necessarily simulate a very stable Holocene climate.

In contrast, changes in ocean temperatures, ice sheet melt, and sea level rise rates were far more abrupt and variable during the Holocene than during the last 100 years. Modern ocean changes are barely detectable in the context of natural variability Image Source(s): Rosenthal et al., 2013; Climate Audit The temperatures of the global ocean have changed by just 0.1°C in the last 50 years, and just 0.02°C during 1994-2013. Image Source: Meltzner et al., 2017. Sea level change in the Middle Ages and the Little Ice Age (LIA) Figuur 2.3. De gemiddelde hoogwater kromme voor de zuidelijke Noordzee (naar Jensen e.a.,1993) en de gemiddelde wereldtemperatuur (volgens Barth & Titus,1984 ) over de laatste 1000 jaar illustreert dat stijging en daling van de mondiale temperatuur samengaat met stijging en daling van het gemiddeld hoogwater (HW).

________________________________________________________________________________________________________________________Behre, 2003 , Behre, 2007 (German North Sea coast, German Bight): Behre, 2004, Abb. 2 (German North Sea coast): Abb. 3: Meeresspiegel an der südlichen Nordseeküste (aus K. -E. See also the critical comments on Behre's sea level curve for the southern North Sea (2003, 2004, 2007) by Baeteman, Waller and Kiden (2011) and Bungenstock and Weerts (2010, 2012), and Behre's response (2012).

North Sea coast of the Netherlands and Belgium Relative sea level rise during the Holocene along the North Sea coast (TNO-NITG, 2003). Grinsted et al., 2009 (Global Sea Level): Relative sea-level change in Newfoundland, Canada during the past ∼3000 years. New Study: Denmark Sea Level Was 11-12.5 Meters Higher Than Now During The Mid-Holocene. By Kenneth Richard on 21. June 2018 In a new paper, data from 57 sites along 17 km of coastal Denmark reveal that sea levels were 11 to 12.5 meters higher than they are today between 7,600 and 4,600 years ago.

Image Source: Clemmensen et al., 2018 Most Holocene reconstructions do not indicate that sea levels were more than about 5 meters above present between about 9,000 to 4,000 years ago. But a new study utilizing well-preserved beach facies along the coasts of northern Denmark indicates that sea levels were as much as 12.5 meters higher than they are today during the Mid-Holocene. These extremely high sea level elevation values may be less common, but other research has revealed that sea levels were as much as 8 meters higher than today near East Antarctica (Hodgson et al., 2016) during the Early Holocene. A high-resolution sea-level proxy dated using quartz OSL from the Holocene Skagen Odde spit system, Denmark Conclusion: Scientists Find Caribbean Sea Levels Were 1 Meter Higher 5300 Years Ago…Today Rising More Slowly. By P Gosselin on 8. July 2018 5300 years ago sea level near Surinam and Guyana was about 1m higher than today By Dr. Sebastian Lüning and Prof. A paper authored by Khan et al. 2017 looked at the Caribbean over the past 10,000 years.

After the end of the last ice age some 11,000 years ago, sea level rose around Surinam and Guyana at a rate of 11 mm per year. During the middle and late Holocene, i.e. over the past 5000 years, sea level rise was only 2.4 mm per year. Drivers of Holocene sea-level change in the Caribbean We present a Holocene relative sea-level (RSL) database for the Caribbean region (5°N to 25°N and 55°W to 90°W) that consists of 499 sea-level index points and 238 limiting dates. No. Doggerland is not a relevant climate change lesson from a “real Atlantis.” 35 Scientific Papers: Global Sea Levels Were 1 – 2 Meters Higher Than Now For Most Of The Last 7,000 Years.

CO2 Concentration Changes Do Not Drive Sea Levels From about 7000 years ago to 2000 years ago, or from the Mid- to Late-Holocene, atmospheric CO2 concentrations varied between only about 260 and 270 parts per million, or ppm. Such low CO2 concentrations are believed to be “safe” for the planet, as they are significantly lower than today’s levels, which have eclipsed 400 ppm in recent years. These high CO2 concentrations are believed to cause dangerous warming, rapid glacier melt, and catastrophic sea level rise. And yet, despite the surge in anthropogenic CO2 emissions and atmospheric CO2 since the 20th century began, the UN’s Intergovernmental Panel on Climate Change (IPCC) has concluded that global sea levels only rose by 1.7 mm/yr during the entire 1901-2010 period, which is a rate of less than 7 inches (17 cm) per century.

A new paper even suggests the global trend is better represented as closer to 1.3 mm/yr, or about 5 inches per century: Prieto et al., 2016 (Argentina, Uruguay) Temperatures, Sea Levels ‘Naturally’ Rise 30 – 40 Times Faster Than Today’s Rates. By Kenneth Richard on 13. April 2017 Modern Temperatures Only Rising 0.05°C/Decade Since 1850, CO2 concentrations have risen from 285 ppm to 400 ppm. During these ~165 years, the IPCC has concluded that surface temperatures have warmed by 0.78°C. This is a warming rate of only 0.05°C per decade for 1850-2012 — which happens to be the same rate of warming over the 1998-2012 period. IPCC AR5 (2013): “The globally averaged combined land and ocean surface temperature data as calculated by a linear trend, show a warming of 0.85°C over the period 1880 to 2012, when multiple independently produced datasets exist. The total increase between the average of the 1850–1900 period and the 2003–2012 period is 0.78 °C, based on the single longest dataset available 4 (see Figure SPM.1). … [T]he rate of warming over the past 15 years (1998–2012; 0.05 °C per decade), which begins with a strong El Niño, is smaller than the rate calculated since 1951 (1951–2012; 0.12 °C per decade).”

Sánchez et al., 2017. Sea Level Decline Over The Past 1,700 Years | The Deplorable Climate Science Blog. A Historic Perspective on the Greenland Ice Sheet and its Contribution to Global Sea Level. Paper Reviewed Vasskog, K., Langebroek, P.M., Andrews, J.T., Nilsen, J.E.Ø. and Nesje, A. 2015. The Greenland Ice Sheet during the last glacial cycle: Current ice loss and contribution to sea-level rise from a palaeoclimatic perspective.

Earth-Science Reviews 150: 45-67. One of the most feared of all model-based projections of CO2-induced global warming is that temperatures will rise to such a degree as to cause a disastrous melting/destabilization of the Greenland Ice Sheet (GrIS), which melting is subsequently projected to raise global sea level by several meters. But how likely is this scenario to occur? And is there any way to prove such melting is caused by human activities? The answer to this two-part question involves some extremely complex and precise data collection and understanding of the processes involved with glacial growth and decay.