10,000 To 5,000 Years Ago, Global Sea Levels Were 3 Meters Higher, Temperatures 4-6° C Warmer

Source: press release for Myers et al., 2015

Sea Levels 2-4 m Higher Until ~5,000 Years Ago

Imply Surface Temps Were At Least 5°C Warmer

According to the accepted (IPCC) formula for calculating the contribution of ocean warming (thermal expansion) to sea level rise upon reaching equilibrium, every additional degrees Celsius of surface warmth yields about 0.4 meter (0.2 to 0.6) to global sea levels.

Moore et al., 2013 “The equilibrium sea level change from thermal expansion alone has been estimated to be ~0.2–0.6 m/°C” (Meehl et al., 2007b).
IPCC AR5: “The amount of ocean thermal expansion increases with global warming (0.2 to 0.6 m/°C–1)”

Considering that much of the globe had sea levels that reached or exceeded 2 to 4 meters above present during the Early to Mid Holocene (~10,000 to ~5,000 years ago), a conversion of 0.4 m/°C  (from thermal expansion alone) would indicate that surface temperatures were at minimum 5°C warmer than now during the first half of the Holocene.  There are many paleoclimate reconstructions of surface temperatures that substantiate such high levels of warming during this period (illustrated below).

It should be noted that during the Early to Mid Holocene, Earth’s CO2 concentrations were only hovering around 260 ppm to 265 ppm – about 140 ppm lower than today’s values (over 400 ppm).

When we consider that 93% of the Earth’s heat is contained in the oceans, which is symbiotically connected to sea level rise and fall via thermal expansion, we can affirm that both surface temperatures and sea levels can and do rise and fall without any meaningful contribution from the atmospheric CO2 concentration.  Therefore, it can be concluded that other internal mechanisms, and not CO2 concentrations, are the driving influence impacting both surface temperatures and sea levels.

Argentina, 3-5 meters higher than present, Bini et al., 2017

The main conclusion is that the relative sea-level between c. 7000 and 5300 cal. yr BP was in the range of c. 2–4 m a.s.l. [above present mean sea level], with a mean value of c. 3.5 m a.s.l. … Initial glacio-hydro-isostatic models of the Patagonian coast [Argentina] suggested that the shoreline could be characterized by currently raised beaches, which started to form as soon as ice-sheet melting ceased (Clark et al., 1978). A more recent model (Milne and Mitrovica, 2008) predicted that RSLs might have exceeded present by c. 5 m at 6000 cal. yr BP. [T]he altimetric and chronological data of the valleymouth terraces show a highstand between c. 7000 and 6600 cal. yr BP at c. 4 m a.s.l. [4 meters above present mean sea level], followed by a progressive fall to c. 2–2.5 m between 6200 and 5300 cal. yr BP.”

Antarctic Peninsula, 15.5 meters higher than present,  Watcham et al., 2011

“The curve shows a mid-Holocene RSL highstand on Fildes Peninsula at 15.5 m above mean sea level between 8000 and 7000 cal a BP.”

South Africa, 3.5 meters higher than present, Lecea et al., 2017

“Ramsay (1995) produced a 9 kyr BP record of sea-level changes from the South African east coast, that showed sea levels reached a high stand of +3.5 m [above present] at 4.65 kyr BP [4,650 years ago]. … In Mozambique, Norström et al., (2012) identified a sea-level highstand ~3 m above present at ~ 6.6 kyr BP.”

Western India, 2 meters higher than present,  Das et al., 2017

“In the absence of any evidence of land-level changes, the study suggests that at around 6 ka to 3 ka [6,000 to 3,000 years ago], the sea was approximately 2 m higher than present.”

Western Sumatra, Indonesia, 2-6 meters higher than present, Dura et al., 2011

“A prominent feature of southeast Asia Holocene sea level records is the mid-Holocene highstand [Geyh et al., 1979; Tjia, 1996; Scoffin and Le Tissier, 1998; Hanebuth et al., 2000], which in Western Sumatra, varies in timing and magnitude from 3000 to 5000 cal years B.P., and +6 to +2 m above present-day sea levels [Horton et al., 2005].”

Denmark, 2.2 meters higher than presentSander et al., 2016

“The data show a period of RSL [relative sea level] highstand at c. 2.2 m above present MSL [mean sea level] between c. 5.0 and 4.0 ka BP [5,000 to 4,000 years before present].”

Africa, 3.5 meters higher than present, Accordi and Carbone, 2016

“Then, the skeletal carbonate storage on the shelf reached its maximum 5 to 4 ka BP [5000 to 4000 years before present] (Ramsay, 1995) during a highstand about 3.5 m above the present sea level, when shallow marine accommodation space was greater than at present.”

Brazil, 4 meters higher than present, Spotorno-Oliveira et al., 2016

“The transgressing sea rapidly rose until reaching the ~ +4 m highstand [above present] level around 5000 years BP.”

Bangladesh, 4.5-5 meters higher than present, Rashid et al., 2012

“The abundant marine diatoms and mangrove pollens indicate the highest RSL [relative sea level] transgression in Bangladesh at approximately 6000 cal BP, being at least 4.5 to 5 m higher than the modern m.s.l. [mean sea level]. … [T]he present shoreline of Bangladesh was established at approximately 1500 cal BP and has not noticeably migrated inland since.”

China, 2-4 meters higher than presentBradley et al., 2016

“In general, the data indicate a marked slowdown between 7 and 8 kyr BP, with sea level rising steadily to form a highstand of ~2-4 m [above present sea level] between 6 and 4 kyr BP [6000 and 4000 years before present]. This is followed by a steady fall, reaching present day levels by ~1 kyr BP.”

East Antarctica, 8 meters higher than presentHodgson et al., 2016

“The geological data imply a regional RSL [relative sea level] high stand of c. 8 m [above present levels], which persisted between 9411 cal yr BP and 7564 cal yr BP [calendar years before present].”

Argentina, Uruguay, 4 – 6.5 meters higher than presentPrieto et al., 2016

“Analysis of the RSL [relative sea level] database revealed that the RSL [relative sea level] rose to reach the present level at or before c. 7000 cal yr BP, with the peak of the sea-level highstand c. +4 m [above present] between c. 6000 and 5500 cal yr BP [calendar years before present] … This RSL [relative sea level] curve was re-plotted by Gyllencreutz et al. (2010) using the same index points and qualitative approach but using the calibrated ages. It shows rising sea-levels following the Last Glacial Termination (LGT), reaching a RSL [relative sea level] maximum of +6.5 m above present at c. 6500 cal yr BP [calendar years before present], followed by a stepped regressive trend towards the present.”

Brazil, 2.7 meters higher than present, Fontes et al., 2017

Vancouver, 1-3 meters higher than presentDura et al., 2016

“RSL [relative sea level] highstand of <1 m (northern Sumatra) and 3 m (western Sumatra) between 6 and 3 ka [6,000-3,000 years ago].”

Thailand-Malaysia, 4-5 meters higher than presentMarwick et al., 2017


“Sinsakul (1992) has summarised 56 radiocarbon dates of shell and peat from beach and tidal locations to estimate a Holocene sea level curve for peninsula Thailand that starts with a steady rise in sea level until about 6 k BP, reaching a height of +4 m amsl (above [present] mean sea level). … Tjia (1996) collected over 130 radiocarbon ages from geological deposits of shell in abrasion platforms, sea-level notches and oyster beds and identified a +5 m [above present] highstand at ca. 5 k BP in the Thai-Malay Peninsula.”

Japan, 2.7 meters higher than presentYokoyama et al., 2016

The Holocene-high-stand (HHS) inferred from oyster fossils (Saccostrea echinata and Saccostrea malaboensis) is 2.7 m [above present sea level] at ca. 3500 years ago, after which sea level gradually fell to present level.”

Uruguay, 3-4 meters higher than presentBracco et al., 2014

“We present a sea level change curve for mid Holocene in Uruguay.  Sea level reached 4 m amsl [above present mean sea level] between 6000 and 5500 yr BP [before present].   A rapid sea level fall to about 1 m amsl [above present mean sea level] was inferred for 4700-4300 yr BP.  A further sea level increase to about 3 m amsl [above present mean sea level] was inferred after 4300 yr BP.  After 4300 yr BP there was a constant sea level a decline.”

New Zealand, 2.75 – 3 meters higher than presentClement et al., 2016

“In North Island locations the early-Holocene sea-level highstand was quite pronounced, with RSL [relative sea level] up to 2.75 m higher than present. In the South Island the onset of highstand conditions was later, with the first attainment of PMSL being between 7000–6400 cal yr BP. In the mid-Holocene the northern North Island experienced the largest sea-level highstand, with RSL up to 3.00 m higher than present.”

Eastern Australia, 2 meters higher than presentMacreadie et al., 2015

“[R]esults from other studies … suggest that high-stand, at perhaps 2 m above present msl[mean sea level] was achieved as early as 7000 radiocarbon years BP [before present](7800 cal. years BP) and that sea-level has exceeded the present value for much of the mid- to late-Holocene [~7000 to ~1000 years ago].”

Thailand, 1.5-3.0 meters higher than present, Scheffers et al., 2012

“Nevertheless, those from the Laem Son coral profile, as well as those from oysters in the Phang-nga Bay show the same trend and maximum altitude lower than +3 m compared with modern RSL (Figure 6a); the maximum of +2.5–3.0 m was timed to c. 5700 cal. BP. … [W]e tentatively deduce a highstand around 5300 BP in the order of +1.5–2.5 m above [present] RSL [relative sea level]”

Kuwait, Qatar, Abu Dhabi, Arabian Gulf, 2-4 meters higher than presentReinink-Smith, 2015

“[A]ssuming the tidal ranges were similar in the middle Holocene, a rough estimate of the MSL [mean sea level] during the middle Holocene highstand is 5.2 m − 1.7 m = +3.5 m above the present MSL [mean sea level]. … The +3.5 m highstand estimate in northeastern Kuwait derived in this study is also higher than the previously reported maximum estimates of +2 to +2.5 m responsible for other Holocene beach ridges in the Arabian Gulf (Gunatilaka, 1986; Lambeck, 1996; Kennett and Kennett, 2007; Jameson and Strohmenger, 2012). Some beach ridges in Qatar and Abu Dhabi are at elevations of 2–4 m above MSL [present mean sea level] as far as 5-15 km inland (Alsharhan and Kendall, 2003).”

Singapore, 2.5 meters higher than present, Bird et al., 2010

“The sea-level curve, corroborated by the indpendent proxy records, suggests rapid rise at a rate of 1.8 m/100 yr until 8100 cal (calibrated) yr B.P., a near cessation in the rate of sea level rise between 7800 and 7400 cal yr B.P., followed by a renewed rise of 4–5 m that was complete by 6500 cal yr B.P [0.5 m/100 yr]. …  A mid-Holocene highstand of ~+2.5 m [above present] was reached after 6500 cal yr B.P., followed by a lowering, with mangroves prograding over the core site by ca. 1000 cal yr B.P.”

South Africa, 3 meters higher than presentStrachan et al., 2014

The mid-Holocene highstands culminated in a sea-level maximum of approximately 3 m above mean sea level (MSL) from 7300 to 6500 cal years BP [calendar years before present] and of 2 m above MSL at around 4000 cal years BP.”

Brazil, 1-4 meters higher than presentHein et al., 2014

“Along the eastern and southern Brazilian coasts of South America, 6000 years of sea-level fall have preserved late-stage transgressive and sea-level highstand features 1–4 m above present mean sea level and several kilometers landward of modern shorelines.”

Reconstructions Of 4 – 6° C Warmer

Temps During The Last 10,000 Years

Svalbard, Arctic, 4-6°C  Warmer Than Present, Mangerud and Svendsen, 2017

“August temperatures on Svalbard were 6°C warmer at around 10.2–9.2 cal. ka BP … 4°C warmer than present between 8.2 and 6 cal. ka BP”

East China, 3-4°C warmer than present, Li et al., 2017

Northern Japan, 3-4°C warmer than present, Kawahat et al., 2017

SST [sea surface temperatures] dropped by 3.5 °C [15.1 to 11.6 °C] within two centuries. Several peaks fluctuate by 2°C over a few centuries.”

Tibetan Plateau, 4-5°C warmer than present, Saini et al., 2017

Fan Lake, Antarctica, 8°C warmer than present, Foster et al., 2016

Arctic Ocean, 3-4 °C warmer than presentBonnet et al., 2010

North Iceland, 5 °C warmer than presentAndersen et al., 2004

Northwest Greenland, 2.5-4 °C warmer than presentLasher et al., 2017

“This paper presents a multi proxy lake record of NW Greenland Holocene climate. … Summer temperatures (2.5–4 °C warmer than present) persisted until 4 ka [4,000 years ago]

Antarctic Peninsula, 4-5°C warmer than present (1,000 years ago), Browne et al., 2017

NW Pacific, 4 °C warmer than present, Yamamoto et al., 2016

North Atlantic, 6°C warmer than present, Mark, 2016

Mediterranean Sea, 4°C warmer than present, Jalali et al., 2016

Alberta, Canada, 8°C warmer than present, Demezhko et al., 2017

British Columbia (Canada), 3-4°C warmer than presentRosenberg et al., 2004

East Greenland, 3-6 °C warmer than present, Lusas et al., 2017

Air temperatures in Milne Land, west of our study area, based on preliminary estimates from chironomids, may have been 3–6°C warmer than at present (Axford et al. 2013)”

Russia2.5° to 7.0°C warmer than present, MacDonald et al., 2000

“Over most of Russia, forest advanced to or near the current arctic coastline between 9000 and 7000 yr B.P. and retreated to its present position by between 4000 and 3000 yr B.P. … During the period of maximum forest extension, the mean July temperatures along the northern coastline of Russia may have been 2.5° to 7.0°C warmer than modern.”

Antarctic Peninsula, 3.5 °C warmer than present, Mulvaney et al., 2012

“A marine sediment record from offshore of the western Antarctic Peninsula also shows an early Holocene optimum where surface ocean temperatures were determined to be ~3.5 °C warmer than present, while the George VI ice shelf on the southwestern Antarctic Peninsula was absent during this early Holocene warm interval before reforming in the mid Holocene.”

11 responses to “10,000 To 5,000 Years Ago, Global Sea Levels Were 3 Meters Higher, Temperatures 4-6° C Warmer”

  1. Bitter&twisted

    It’s worse than we thought!!
    We are all going to drown/fry/starve/freeze/get blown away/die of thirst if we don’t stop emitting CO2 NOW!!

    SebastianH you were right all along.
    Please accept my grovelling apologies


  2. tom0mason

    Thank-you Kenneth Richard,

    A nice compilation.
    I see that at any point in time across the globe the actual climate effects (SST, sea level variations) though coordinated are not synchronized.
    Some much for homogenized data across large areas being meaningful.

  3. DMA

    A very interesting and informative article. Thank you Kenneth. Your salient points are correct even if my contention of minor error is correct. I contend that the reliance on ice cores to estimate ancient CO2 concentrations is improper so your statements of CO2 levels are questionable. Maybe you could give us one your collections of works that show my contention. It would include Jaworowski and Segalstad on the ice core problems and Wallace on stomatta evidence of higher CO2 in the earlier Holocene and Beck on higher CO2 by chemical analysis more recently. I’m not a very good researcher and I bet you would find a lot more material along these lines.
    Thanks again

  4. 10,000 To 5,000 Years Ago, Global Sea Levels Were 3 Meters Higher, Temperatures 4-6° C Warmer – Infinite Unknown

    […] – 10,000 To 5,000 Years Ago, Global Sea Levels Were 3 Meters Higher, Temperatures 4-6° C Warmer […]

  5. 4 Eyes

    Ask local Aborigines in North Queensland about sea level rise many years ago. Their folklore says the sea rushed in over the flats which are now the Great Barrier Reef. If you work it out it encroached at up to 20 kms per year. They thought it was a giant stingray flapping its fins that caused the water to rush in so fast.

  6. Robert Clark

    There are three methods of heat transfer. They are conduction, convection, and radiant heat. Heat transfer to or from the earth can only be done by radiant. All material contains heat and is radiating it to cooler surfaces or absorbing it from warmer surfaces. The difference is the heat gain or loss of the material.

    The earth gains heat radiated from the sun and loses heat it radiates to outer space, called black sky radiation. Outer space is considered absolute zero.

    The amount of radiant heat hitting the earth from the sun daily is relatively constant. The radiant heat lost daily by the earth thru black sky radiation is constant since absolute zero is constant. The amount of heat gained by the earth’s surface depends on the surface area of the earth covered by water relative to that covered by land. Land area absorbs a larger percent of the radiant heat relative to the water area since the surface of the water reflects a percentage of the radiant heat back to outer space. The daily access heat, or loss of heat, is transferred to the oceans thru conduction and convection where it works its way to the poles and it freezes water adding to the polar ice caps or melts the polar ice caps thus keeping the temperature of the oceans, thus the earth, relatively constant. As the polar ice caps grow or melt, the surface area of the earth covered by land relative to that covered by water changes. This is the definition of global warming.

    That radiant heat absorbed by oceans and land masses is transferred to the atmosphere thru conduction and convection. When it is winter in one hemisphere it is summer in the other and the same with spring and fall. I would think the average temperature of the lower 5,000 feet of the atmosphere changes about 10’F to20’F each day. This probably takes more heat than man has added to the earth in the last 50 years. That heat man adds to the atmosphere each day is radiated to the black sky and the infinitesimal amount left helps melt the ice during global warming, should be called Global Defrosting, . The scientists have taken core samples of the polar ice caps and know how close we are to the ice left at the beginning of the last ice age. That is how close we are to the end of global warming or we have already begun global cooling, should be called global ice making. According to the Antarctic ice core we began the new ice age about 11,000 years ago.

    Absolute Zero is -459.68’F and the surface temperature of the sun is between 7,300’F and 10,000’F. If we could go back in time 12,000 years, the end of the last ice age, we would probable see that the average daily temperature of the earth was in the mid 60’F as it is today. You must understand the amount of heat gained every 24 hours is almost equal to that lost during the same 24 hours. Angle of the earth’s axis is 23.5’.

    The above in simple English.

    The average surface temperature of the earth is 63.5’f. The heat loss to black sky radiation every 24 hours is constant. The average radiant heat striking the surface of the earth is relatively constant. Because the sun is an active star the average temperature will change over centuries. As the surface area of the earth covered by water increases, the more radiant heat is reflected back to the black sky increases. When the daily radiant heat gained by the earth from the sun in 24 hours is less than that lost by black sky radiation we will begin ice making. Looking at the ice core from the Antarctic we can see that the earth began the new Ice Age about 12,000 years ago.

    The Weather Channel just had a piece of a very large section of ice is about to break off a peninsula in the Antarctic. Could this be because of the fact that 12,000 years ago the earth switched from Global Ice Melting to Global Ice Making. Since then the Ocean levels may have dropped a foot and the ice has risen around 600’ in the Antarctic. It seems like that would be a tremendous amount of leverage attempting to break off that ice.

    The Arctic ice core chart also shows the top 500’ is the beginning of the Industrial Revolution, thus the increase of CO2 rise in the atmosphere. The chart also shows that as the ocean level drops the CO2 level in the atmosphere drops. This is because the land surface area grows, thus the green foliage increases, thus the photosynthesis, which is how nature removes the CO2 from the atmosphere, lowers the CO2 level. Oceans were about 400’ lower than they are now at the peak of the ice age and global ice melting began. The last ice age lasted about 120 thousand years. That means it took about 60 thousand years to melt the ice, thus the oceans rose an average of 6.67 feet per thousand years.

  7. gallopingcamel

    @Robert Clark,
    “There are three methods of heat transfer. They are conduction, convection, and radiant heat.”

    Somehow you forgot latent heat that cannot be ignored on bodies that have oceans. In this solar system that means Earth and Titan. For a mathematical model that predicts the warming effect of dense atmospheres with amazing accuracy I recommend Robinson & Catling:

    Unlike most papers on “Climate Science” the above paper provides sufficient information to allow replication of the results. See here: