By Joe D’Aleo, CCM, AMS Fellow, Co-Founder The Weather Channel and Dr. Don Easterbrook, Emeritus Professor of Geology, Western Washington University
January 28, 2021
The Arctic includes the Arctic Ocean, Greenland, Iceland, and part of Siberia and northern Alaska. Because of the absence of any land mass in the Arctic Ocean, most of area lacks glaciers, which require a land mass. Thus, most of the Arctic contains only floating sea ice. Greenland, Iceland, northern Alaska, and northern Siberia contain the only glaciers in the general Arctic region.
Arctic warming and the melting of the arctic ice are not at all unprecedented (they happen predictably on multidecadal scales with a period of around 60 years) and are in fact entirely natural. Warming results in part from the reduction of arctic ice extent because of flows of warm water into the arctic from the Pacific through the Bering Straits and from the Atlantic from the far North Atlantic Current. The warmer water thins the ice from beneath, slows the refreezing and limits to varying degrees the depth and extent of the ice.
The arctic ice is unlike the Glaciers on land in Greenland, the Antarctic and in the world’s mountain ranges is floating on water and the melting has no effect on sea level (much as ice in cold beverages doesn’t cause the liquid to overflow the glass when it melts).
The Monthly Weather Review in 1922 alerted to the start of this warming period “a radical change in climatic conditions, and hitherto unheard-of high temperatures”
ftp://ftp.library.noaa.gov/docs.lib/htdocs/rescue/mwr/064/mwr-064-02-c1.pdf
Polyakov et al (2002) created a temperature record using stations north of 62 degrees N. The late 1930s-early 1940s were clearly the warmest of the last century. In addition, the numbers of available observations in the late 1930s-early 1940s (slightly more than 50) is comparable to recent decades. ‘
MULTIDECADAL OCEAN CYCLES AND THE ARCTIC
The Japan Agency for Marine-Earth Science and Technology in Yokosuka, Kanagawa Prefecture observed in a story in Yahoo Asia News in 2005 an ice shrinkage in the western Arctic Ocean from 1997 to 1998 that they attributed to “… by the flow to the area of warm water from the Pacific Ocean, not by atmospheric impact as previously thought”. This was related to the super El Nino of 1997/98. JAMSTEC’s Koji Shimada, the group’s sub-leader, said the shrinkage was particularly severe in the Pacific side of the Arctic Ocean. The ocean’s ratio of area covered with ice during the summer stood at about 60-80 percent from the 1980s to mid-1990s, but it went down to 15-30 percent after 1998, he said. Trenberth (1999) also has acknowledged this warming effect of El Nino on the arctic.
The cycle with respect to arctic temperatures and ice relate to multidecadal cycles in ocean temperatures in both the Pacific (Pacific Decadal Oscillation or PDO) and Atlantic (Atlantic Multidecadal Oscillation or AMO).
THE PACIFIC DECADAL OSCILLATION (PDO)
The Pacific warm mode favors more El Ninos and warmer water in the far northern Pacific including the Bering Straits. The PDO flipped into its warm mode in 1978 and the arctic temperatures began to warm and ice began to melt repeating what happened in the 1910s to early 1940s time period.
Notice how the temperatures in Alaska go through step changes tied to the PDO (Keen, 2011).
In the winter 0f 2019/20, at Fairbanks average daytime high was -2.1F, while the daytime low -20F, average daily mean was -11F! The coldest was -43F while the warmest was 31F December 9. 33 days were at or below -30F, 5 were at or below -40F. The winter averaged 4.7F below normal, the 3rd coldest since before the Great Pacific Climate Shift (a shift of the so called Pacific Decadal Oscillation to positive) in the late 1970s when warmer Pacific waters favored warmth in Alaska and western North America.
THE ATLANTIC’S ROLE
The Atlantic also cycles on a 60-70 year period. The Atlantic Multidecadal Oscillation or AMO returned to the positive warm mode in 1995.
Frances et al. (GRL 2007) showed how the warming in the arctic and the melting ice was related to warm water (+3C) in the Barents Sea moving slowly into the Siberian arctic and melting the ice. She also noted the positive feedback of changed “albedo” due to open water then further enhances the warming.
The International Arctic Research Center at the University of Alaska, Fairbanks showed how arctic temperatures have cycled with intrusions of Atlantic water – cold and warm beneath the ice.
Of the two oceans, for the larger arctic basin, the Atlantic may be more important.
Pryzbylak (2000) says:
“There exists an agreement in estimating temperature tendencies prior to 1950. Practically all (old and new) of the papers which cover this time period concentrate on the analysis of the significant warming which occurred in the Arctic from 1920 to about 1940….In the Arctic, the highest temperatures since the beginning of instrumental observation occurred clearly in the 1930s. Moreover, it has been shown that even in the 1950s the temperature was higher than in the last 10 years.”
“For arctic temperature, the most important factor is a change in the atmospheric circulation over the North Atlantic” The influence of the atmospheric circulation changes over the Pacific (both in the northern end and in the tropical parts) is significantly lower”
As is the case for US temperatures, the combination of the PDO and AMO Indexes (PDO+AMO) again has considerable explanatory power for Arctic average temperature.
“In approximately the last 140 years, there have been two periods of significant temperature increases in the Arctic. The first began in around 1918–1920 and lasted until 1938 and has been called the ‘1930s warming’ (Bengtsson et al. 2004). Other works have referred to this period as the ‘Early Twentieth Century Warming’ (ETCW, Brönnimann 2009) or the ‘Early Twentieth Century Arctic Warming’ (ETCAW, Wegmann et al. 2017, 2018)
Karlen (2005) reported on historical temperatures in Svalbard (Lufthavn, at 78 deg N latitude), claiming that the area represents a large portion of the Arctic. It is reported that the “mean annual temperature increased rapidly from the 1910s to the late 1930s.” Later, temperatures dropped, “and a minimum was reached around 1970.” Once again, “Svalbard thereafter became warmer, but the mean temperature in the late 1990s was still slightly cooler than it was in the late 1930s.”
Drinkwater (2006) concluded that “in the 1920s and 1930s, there was a dramatic warming of the air and ocean temperatures in the northern North Atlantic and the high Arctic, with the largest changes occurring north of 60°N,” which “led to reduced ice cover in the Arctic and subarctic regions and higher sea temperatures.” This was “the most significant regime shift experienced in the North Atlantic in the 20th century.”.
Hanna, et al (2006) estimated Sea Surface Temperatures (SSTs) near Iceland over a 119-year period based on measurements made at ten coastal stations located between latitudes 63°’N and 67°’N. They concluded that there had been “generally cold conditions during the late nineteenth and early twentieth centuries; strong warming in the 1920s, with peak SSTs typically being attained around 1940; and cooling thereafter until the 1970s, followed once again by warming – but not generally back up to the level of the 1930s/1940s warm period.”
THE EFFECT ON ICE COVER
Both the Atlantic and Pacific play roles in arctic ice extent. The sea ice extent diminished following the Great Pacific Climate Shift (flip of the PDO to positive) in the late 1970s. It stayed relatively stable until early 2000s when a more precipitous decline began, related to a spike in North Atlantic warmth and a positive AO.
Dmitrenko and Polyokov (2003) observed that warm Atlantic water in the early 2000s from the warm AMO that developed in the middle 1990s had made its way under the ice to off of the arctic coast of Siberia where it thinned the ice by 30% much as it did when it happened in the last warm AMO period from the 1880s to 1930s.
The University of Colorado’s National Snow and Ice Data Center (NSIDC) summarized the role of the ocean cycles very well in October 2007 in this way:
“One prominent researcher, Igor Polyakov at the University of Fairbanks, Alaska, points out that pulses of unusually warm water have been entering the Arctic Ocean from the Atlantic, which several years later are seen in the ocean north of Siberia. These pulses of water are helping to heat the upper Arctic Ocean, contributing to summer ice melt and helping to reduce winter ice growth.
Another scientist, Koji Shimada of the Japan Agency for Marine–Earth Science and Technology, reports evidence of changes in ocean circulation in the Pacific side of the Arctic Ocean. Through a complex interaction with declining sea ice, warm water entering the Arctic Ocean through Bering Strait in summer is being shunted from the Alaskan coast into the Arctic Ocean, where it fosters further ice loss.
Many questions still remain to be answered, but these changes in ocean circulation may be important keys for understanding the observed loss of Arctic sea ice.”
THE SUN AS THE ULTIMATE DRIVER FOR CLIMATE IN ARCTIC
As to the driver for the multidecadal ocean cycles it may well be the solar cycles. Soon (GRL 2005) showed how the Arctic temperatures (Polyakov) correlated extremely well with the total solar irradiance (Hoyt-Schattem) (r-squared of 0.79). This compared to an r-squared correlation of just 0.22 with the CO2.
GREENLAND
Greenland is often considered a sign of climate change. The data here too suggests it is cyclical and relates to ocean cycles on century scales and longer. Note the current interglacial period ice core data tells us the last 10,000 years shows 1000-year cycles. They have slowly declined as we move towards the end of the interglacial period (usually just over 10,000 years in length. The last warm period called the Medieval Warm Period saw ice retreat in Greenland enough to entice the Vikings to settle Greenland and grow crops including grapes for wine. They abandoned it as we cooled towards the Little Ice Age.
ANTARCTICA
The figure below shows temperature changes during the past 30 years, compared to temperatures recorded between 1950 and 1980. Most of Antarctica is cooling, with warming occurring over just a small portion of the continent that juts out into the Southern Ocean. That region is volcanic with both surface and sea bottom vents. It is also subject to periodic warming from winds that blow downslope and locally warm by compression.
THE ANTARCTIC ICE SHEET IS GROWING, NOT MELTING.
Previous studies showed cooling across all of the much larger East Antarctic Ice Sheet and warming limited to the Antarctic Peninsula of west Antarctica. In 2009, Steig et al. published a controversial paper, “Warming of the Antarctic Ice-Sheet Surface Since the 1957 International Geophysical Year,” in Nature contending that warming instead was occurring.
Measured satellite and surface temperatures confirm the lack of warming over most of Antarctica. The UAH and RSS satellite records are the most comprehensive.
The main conclusion to be drawn from these data is that at least 95% of glacial ice in Antarctica is increasing, not melting.
Cooling of the Southern Ocean around Antarctica
The Southern Ocean around Antarctica has been getting markedly colder since 2006. Sea ice has increased substantially, especially since 2012.
WEST ANTARCTIC ICE SHEET
The West Antarctic Ice Sheet occupies a deep basin west of the main East Antarctic Ice Sheet. It comprises only about 8% of glacial ice in Antarctica. The Antarctic Peninsula has been cooling sharply since 2006. Ocean temperatures have been plummeting since about 2007, sea ice has reached all-time highs, and surface temperatures at 13 stations on or near the Antarctic Peninsula have been cooling since 2000. A plot of temperature anomalies at 13 Antarctic stations on or near the Antarctic Peninsula show that the Antarctic Peninsula was warming up until 2000 but has been cooling dramatically since then.
The Larsen Ice Shelf Station has been cooling at an astonishing rate of 1.8° C per decade (18°C per century) since 1995 (Fig. 8). Nearby Butler Island records even faster cooling at 1.9 C/decade. Sea ice around Antarctica is increasing because ocean temperature from the surface to 100 m dropped below the freezing point in 2008 and has stayed there since.
Annual average temperature at the Larsen Ice Shelf shows sharp cooling (1.8 ° C/decade). (Easterbrook, 2016) (From GISTemp.)
SUMMARY
Multidecadal Oscillations in the Pacific and the Atlantic are acknowledged to be the result of natural processes. The warm mode of the Pacific results in warm water off Alaska that can enter the arctic through the Bering Strait and produce arctic ice melt. The warm mode of the AMO also results in warming in the North Atlantic waters, which are carried by the North Atlantic current into the arctic reducing ice depth and extent. When you combine the two cycles, you can explain the temperature and ice cover variances of the past 110 years for the Arctic. Greenland data suggests the recent warming falls far short of earlier warming periods during the current interglacial and short of the warming early in the 20th century. The Antarctic has cooled and ice has increased in recent years although volcanism near the Antarctic peninsula leads to local water warmth and sea ice melting. Prior to the recent meting, the ice cover reached a long-term record high.
Also we should note that the prescribed melting reported in the Science Journal can’t be claimed a long time record as global ocean data prior to the satellite (1980) and Argo Buoy era (post 2004) is spotty at best.
Even if the claims about water released were true, computations show global sea level would rise just 4 inches/century (agreeing with global data) and not the up to 24 feet promised decades ago. See the sea level story here.
References:
Arctic Climate Assessment (ACIA), 2004. Impacts of a warming Arctic.
Cambridge University Press, Cambridge,UK
Changnon, S., Winstanley, D.:2004: Insights to Key Questions about Climate Change, Illinois State Water Survey http://www.sws.uiuc.edu/pubdoc/IEM/ISWSIEM2004-01.pdf
Christy, J.R., R.W. Spencer and W.D. Braswell, 2000: MSU tropospheric temperatures: Dataset construction and radiosonde comparisons. J. Atmos. Oceanic Tech., 17, 1153-1170.
Climate Change Impacts on the United States: The Potential Consequences of Climate Variability and Change National Assessment Synthesis Team USGRCP, June 2000
Delworth, T.L. ,and M.E. Mann, 2000: Observed and simulated multidecadal variability in the Northern Hemisphere. Climate Dyn., 16, 661–676.
Drinkwater, K.F. 2006. The regime shift of the 1920s and 1930s in the North Atlantic. Progress in Oceanography68: 134-151.
Gray, S.T., et al., 2004: A tree-ring based reconstruction of the Atlantic Multidecadal Oscillation since 1567 A.D.Geophys. Res. Lett., 31, L12205, doi:10.1029/2004GL019932
Hanna, E., Jonsson, T., Olafsson, J. and Valdimarsson, H. 2006. Icelandic coastal sea surface temperature records constructed: Putting the pulse on air-sea-climate interactions in the Northern North Atlantic. Part I: Comparison with HadISST1 open-ocean surface temperatures and preliminary analysis of long-term patterns and anomalies of SSTs around Iceland. Journal of Climate 19: 5652-5666.
Hass, C., Eicken, H., 2001: Interannual Variability of Summer Sea Ice thickness in the Siberian and central Arctic under Different Atmospheric Circulation Regiomes, JGR, 106, 4449-4462
IPCC Fourth Assessment 2007
Johannessewn, O.M., Shalina, E.V., Miles, M. W., (1999): Satellite Evidence for an Arctic Sea Ice Cover in Transformation, Science, 286, 1937-1939
Karlen, W. 2005. Recent global warming: An artifact of a too-short temperature record? Ambio 34: 263-264.
Kerr, R. A., A North Atlantic climate pacemaker for the centuries,
Science, 288 (5473), 984-1986, 2000.
Latif, M. and T.P. Barnett, 1994: Causes of decadal climate variability over the North Pacific and North America. Science 266, 634-637.
Polyakov, I., Walsh, D., Dmitrenko, I., Colony, R.L. and Timokhov, L.A. 2003a. Arctic Ocean variability derived from historical observations. Geophysical Research Letters 30: 10.1029/2002GL016441.
Polyakov, I., Alekseev, G.V., Timokhov, L.A., Bhatt, U.S., Colony, R.L., Simmons, H.L., Walsh, D., Walsh, J.E. and Zakharov, V.F., 2004. Variability of the Intermediate Atlantic Water of the Arctic Ocean over the Last 100 Years. Journal of Climate 17: 4485-4497.
Proshutinsky, A.Y., Johnson, M.A., 1997: Two Circulation Regimes of the Wind Driven Arctic, JGR, 102, 12493-12514
Przybylak, R., 2000, Temporal And Spatial Variation Of Surface Air Temperature Over The Period Of Instrumental Observations In The Arctic, Intl Journal of Climatology, 20: 587–614
Rigor, I.G., Wallace, J.M. and Colony, R.L., 2002. Response of Sea Ice to the Arctic Oscillation. Journal of Climate 15: 2648-2663.
Rothrock, D.A., Yu, Y., Maykut, G.A., 1999: Thinning of the Arctic Sea-Ice Cover, GRL, 26, no23 3469-3472
Soon, W.H., “Variable Solar Irradiance as a Plausible Agent for Multidecadal Variationsin the Arctic-wide Surface Air Temperature Record of the Past 130 Years,” Geophysical Research Letters , Vol. 32,doi:10.1029/2005GL023429.
Thomas, R., Akins, T., Csatho, B., Fahenstock, M., Goglneni, P., Kim, C., Sonntag, J., (2000): Mass Balance of the Greenland Ice Sheet at High Elevations, Science, 289, 427
Trenberth, K.E., and J.W. Hurrell, 1999: Decadal atmosphere-ocean variations in the Pacific. Clim. Dyn., 9, 303-319.
Venegas, S.A., Mysak, L.A., 2000: Is There a Dominant Time scale of Natural Climate Variability in the Arctic, Journal of Climate, October 2000,13, 3412-3424
Wadhams , P., Davis, N.R., 2000: Further Evidence of Ice thinning in the Arctic Ocean, GRL, 27, 3973-3975 Winsor, P.,(2001) Arctic Sea ice Thickness Remained Constant During the 1990s: GRL 28, no6 1039-1041
During WWII, the Northern Sea Route (NSR) along the Siberian coast was open in summer, as it usually is now. Both Soviet and sneaky German ships used it.
But in the multidecadal cool cycle following the Early 20th Century Warming, the NSR remained closed by summer ice. Hence nuclear-powered ice breaker Lenin:
https://en.wikipedia.org/wiki/Lenin_(1957_icebreaker)
Study from last year on Holocene Arctic sea ice:
Holocene variability in sea ice and primary productivity in the northeastern Baffin Bay
https://link.springer.com/article/10.1007/s41063-020-00075-y
Abstract (full paper available)
Arctic sea ice is a critical component of the climate system, known to influence ocean circulation, earth’s albedo, and ocean–atmosphere heat and gas exchange. Current developments in the use of IP25 (a sea ice proxy with 25 carbon atoms only synthesized by Arctic sea ice diatoms) have proven it to be a suitable proxy for paleo-sea ice reconstructions over hundreds of thousands to even millions of years. In the NE Baffin Bay, off NW Greenland, Melville Bugt is a climate-sensitive region characterized by strong seasonal sea ice variability and strong melt-water discharge from the Greenland Ice Sheet (GIS). Here, we present a centennial-scale resolution Holocene sea ice record, based on IP25 and open-water phytoplankton biomarkers (brassicasterol, dinosterol and HBI III) using core GeoB19927-3 (73° 35.26′ N, 58° 05.66′ W). Seasonal to ice-edge conditions near the core site are documented for most of the Holocene period with some significant variability. In the lower-most part, a cold interval characterized by extensive sea ice cover and very low local productivity is succeeded by an interval (~ 9.4–8.5 ka BP) with reduced sea ice cover, enhanced GIS spring melting, and strong influence of the West Greenland Current (WGC). From ~ 8.5 until ~ 7.8 ka BP, a cooling event is recorded by ice algae and phytoplankton biomarkers. They indicate an extended sea ice cover, possibly related to the opening of Nares Strait, which may have led to an increased influx of Polar Water into NE-Baffin Bay. The interval between ~ 7.8 and ~ 3.0 ka BP is characterized by generally reduced sea ice cover with millennial-scale variability of the (late winter/early spring) ice-edge limit, increased open-water conditions (polynya type), and a dominant WGC carrying warm waters at least as far as the Melville Bugt area. During the last ~ 3.0 ka BP, our biomarker records do not reflect the late Holocene ‘Neoglacial cooling’ observed elsewhere in the Northern Hemisphere, possibly due to the persistent influence of the WGC and interactions with the adjacent fjords. Peaks in HBI III at about ~ 2.1 and ~ 1.3 ka BP, interpreted as persistent ice-edge situations, might correlate with the Roman Warm Period (RWP) and Medieval Climate Anomaly (MCA), respectively, in-phase with the North Atlantic Oscillation (NAO) mode. When integrated with marine and terrestrial records from other circum-Baffin Bay areas (Disko Bay, the Canadian Arctic, the Labrador Sea), the Melville Bugt biomarker records point to close ties with high Arctic and Northern Hemispheric climate conditions, driven by solar and oceanic circulation forcings.
Dear friends,
My modest contribution to the subject:
https://helda.helsinki.fi/bitstream/handle/10138/243251/Kilpisj%c3%a4rvi_Notes_26_2017_pdf.pdf?sequence=1&isAllowed=y
Best wishes, Antero Järvinen, kilpisjarvinen@gmail.com
Thanks. I don’t read Finnish, but the imagery was instructive.
From 2014:
https://www.sciencedirect.com/science/article/pii/S0277379113004162
Arctic Ocean perennial sea ice breakdown during the Early Holocene Insolation Maximum
AbstractArctic Ocean sea ice proxies generally suggest a reduction in sea ice during parts of the early and middle Holocene (∼6000–10,000 years BP) compared to present day conditions. This sea ice minimum has been attributed to the northern hemisphere Early Holocene Insolation Maximum (EHIM) associated with Earth’s orbital cycles. Here we investigate the transient effect of insolation variations during the final part of the last glaciation and the Holocene by means of continuous climate simulations with the coupled atmosphere–sea ice–ocean column model CCAM. We show that the increased insolation during EHIM has the potential to push the Arctic Ocean sea ice cover into a regime dominated by seasonal ice, i.e. ice free summers. The strong sea ice thickness response is caused by the positive sea ice albedo feedback. Studies of the GRIP ice cores and high latitude North Atlantic sediment cores show that the Bølling–Allerød period (c. 12,700–14,700 years BP) was a climatically unstable period in the northern high latitudes and we speculate that this instability may be linked to dual stability modes of the Arctic sea ice cover characterized by e.g. transitions between periods with and without perennial sea ice cover.
From 2006, with multiple paleoproxies, eg marine mammals, forams, diatoms and isotopes:
https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2006EO280001
Natural Variability of Arctic Sea Ice Over the Holocene
Only one german raider (“Komet”) went through, in 1940, and it did need assistance from Soviet Icebreakers, admittedly only for two rather short stretches.
Going through the NSR without icebreaker assistance has really never been practical, even in late summer/autumn, except for quite small craft
You’re right. Thanks.
Doubtful any ship could have got through without ice breaking aid.
But less ice during the war than in the postwar period before the dramatic PDO shift of 1977-78.
Panic!!
What a great report! Oscillations/cycles messing with the data without any help from CO2? Great stuff. The direct value of this report is an example of two great scientists teaming up, and the D’Aleo/Easterbrook TagTeam can coax any topic into submission. Great stuff!
Thanks for the kind words!
How about no more preposterous punts.
“Cycles” does not explain this: https://www.livescience.com/4702-melting-glacier-reveals-ancient-tree-stumps.html
or in visual terms:
https://www.bing.com/images/search?q=before%2fafter+images+glaciers&qpvt=before%2fafter+images+glaciers&form=IQFRML&first=1&tsc=ImageHoverTitle
Yes, it was much warmer in past, than it is now.
Thank you for acknowledging that simple truth.
You missed the point, D’Aleo and Esterbrook’s explanation doesn’t account for the tree stump’s carbon dating.
You need to read better
They do discuss the longer cycles and the general downward temperature trend of the Neoglaciation.
They even show it in the GISP data showing warmer during the MWP, RWP and Minoan warm period
ALL of which were warmer than the current slightly warm period.
Explain why not. Can’t follow your argument if it will be one.
You mean these ancient tree stumps?
The ones in Siberia that show that the treeline 1000 years ago (in the MWP) was at the same latitude that the treeline has now reached with its northward march. So the treeline shows same temperatures in the MWP as now.
https://ptolemy2.wordpress.com/2020/07/09/the-to-and-fro-of-the-siberian-taiga-tundra-treeline/
Actually it doesn’t address the tree’s carbon dating, and it doesn’t need to.
Intelligent people understand that there are many factors that impact temperatures in the arctic.
Sure they do.
Climate is cyclical at various time scales, from decades to at least tens of millions of years.
Don’t overstrain bethan.
Unfortunately D’Aleo and Esterbrook don’t mention them.
They show the Alley Greenland graph of Holocene land ice. But the rest of their discussion covers only data since AD 1880, so why should they mention longer cycles?
They show the GISP graph, what else is needed.
Or are graphs beyond your limited understanding.?
A piece about Arctic temperature with “What they don’t tell you” in the headline…never mentions AGW. That has to be a new high water mark for irony.
.
Why should they ???
The only “AGW” comes from urbanisation and land use changes…
…. and those sure ARE NOT GLOBAL,
They are only very small percentages of land area
(….but a HUGE part of the farce that is the Global Average Surface Temperature.)
As you are well aware, there is no empirical scientific evidence of warming by atmospheric CO2.
If you think there is… then produce it.
Arctic temperatures are similar to what they were in the 1940’s, and BELOW what they were in the MWP and nearly all the last 10,000 years
Why would they bother mentioning the NON-science of the AGW fantasy ?
Why should it mention AGW? Not everything is the result of man.
”never mentions AGW.”
Because it is irrelevant.
Do you want to return to the cold of the 70s?
Btw, it was -27 F in Bemidji Mn yesterday….balmy indeed.
Loydo,
Everyone here is well aware of the claimed link between CO2 and climate, so no irony is involved and your claim is false. All the evidence given in this post strongly suggests that CO2 plays a very minor role in the climate.
But there is an irony in your post. Anthropogenic greenhouse warming only occurs in – well, greenhouses, basically. Greenhouses do *not* work by trapping radiation. They work by trapping warm air. It is very appropriate that the AGW unproven theory has a name based on junk science and scientific ignorance. Now that is actually quite ironic.
Chris
Don’t look now bethan, but you are starting to look desperate.
You are conflating presumptions with science.
“D’Aleo and Esterbrook” wrote an analysis about long term cycles governing Polar ice melt.
They did not write an article that encompasses every ice melt worldwide.
Nor do “D’Aleo and Esterbrook” address specific non cyclical significant contributors to ice melt, including that of mountain glaciers; e.g. black carbon deposits on ice.
Nor do “D’Aleo and Esterbrook” address the LIA ‘Little Ice Age’ that caused glaciers to advance almost everywhere. And the gradual warming from the depths of the LIA.
Cold, including accreting glaciers is historically proven to be a killer.
This modern warm period is not deadly, anywhere. In spite of alarmists fantasizing wildlife and human dooms.
There are dang good reasons geologists, paleontologists and archeologists term warm periods as ‘Optimums’. They are optimal periods for mankind, wildlife and sea life world wide.
John, afraid you went over bethan’s comprehension there. I mean, cyclical at various time-scales?
2 points
First, for years, we’ve been told that the rising temperatures since the 70’s were caused by CO2 and CO2 only. Those of us who have studied the past have always known that this was garbage. Now there is yet more science that agrees.
Second, thank you for helping to demonstrate that the arctic was much warmer in the not to distant past, than it is today.
You are correct in your implication that there is more than short term cycles going on here.
However, the people you are arguing with have never believed or declared that there is only one factor that controls climate.
That has been the myth pushed by those you support.
The somewhat erratic cycle of the AMO is still visible in the Icelandic sea ice data.
LIA was a time of anomalously high Arctic sea ice…
1970s extent was similar to periods during the LIA.
Most of the Holocene has had much less sea ice than now.
Bethan
Why do you enter your email address in the field for your name?
Do you need help reading?
(No shame in that)
A very welcome history of polar ice. Sincere thanks to d’Aleo and Easterbrook for this concise but comprehensive review of the issue; I’m going to keep it handy for future reference.
I’m already getting a sense that climate alarmism is starting to ramp up again (not that it ever stopped, but it did slow down a bit while covid19 was about to wipe us all off the face of the earth). Now that president Biden is going to conquer the pandemic, Firefox has decided to start softening me up for future draconian rules by adding climate stories to the links it “suggests” for me when I open a new page. Here are the clickbait headlines from this morning’s offerings:
“<i>The Climate Crisis Is Worse Than You Can Imagine. Here’s What Happens If You Try</i>”
“<i>Earth is now losing 1.2 trillion tons of ice each year. And it’s going to get worse.Ice is melting faster worldwide, with greater sea-level rise anticipated, studies show.</i>”
Will the deluge of manufactured bad news ever stop? No, it’s going to get worse, studies show. In fact it’s going to reach a tipping point, scientists say. It’s getting dark outside.
manual html tags are not very helpfull, use just the tag box below
“climate alarmism is starting to ramp up again”. The left HAS to ramp up all efforts as they, too, can see a colder future for the world. If the US government can spread a few billion dollars around, the leftists will claim they saved the world in just a few short years.
”the leftists will claim they saved the world in just a few short years.”
I thought that too, gut they will have to explain why the co2 has not fallen.
Oh, no worries – they’ll come up with some pseudo-scientific “explanation” (in the “dog ate my homework” mode) for that.
Or, they’ll just blame cooling temperatures on fossil fuel use too. Just like last time.
Greenland Ice Mass since 1900 (using PIOMAS/GRACE data)
Antarctic Ice Mass since 1900 (using any data you choose)
I wonder if old Joe has the same handlers as old David Attenborough?
Either way, it’s still more elder abuse.
AMO and PDO are two different variable, hence the sum of AMO+PDO is a bit misleading, it would be more appropriate to say ‘when AMO & PDO are in/out of phase this or that might happen.
Joe,
Here’s a paper published a few years ago that strongly supports one of your conclusions.
Arctic Air Temperature Change Amplification and the Atlantic Multidecadal Oscillation
Geophysical Research Letters
Petr Chylek – Space and Remote Sensing, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
Chris K. Folland – Met Office Hadley Centre for Climate Change, Exeter, UK
Glen Lesins -Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
Manvendra K. Dubey – Earth and Environmental Sciences, Los Alamos National Laboratory, Los Alamos, New Mexico, USA
Muyin Wang – Joint Institute for the Study of the Atmosphere and Ocean, University of Washington, Seattle, Washington, USA
Abstract
Understanding Arctic temperature variability is essential for assessing possible future melting of the Greenland ice sheet, Arctic sea ice and Arctic permafrost. Temperature trend reversals in 1940 and 1970 separate two Arctic warming periods (1910–1940 and 1970–2008) by a significant 1940–1970 cooling period. Analyzing temperature records of the Arctic meteorological stations we find that (a) the Arctic amplification (ratio of the Arctic to global temperature trends) is not a constant but varies in time on a multi-decadal time scale, (b) the Arctic warming from 1910–1940 proceeded at a significantly faster rate than the 1970–2008 warming, and (c) the Arctic temperature changes are highly correlated with the Atlantic Multi-decadal Oscillation (AMO) suggesting the Atlantic Ocean thermohaline circulation is linked to the Arctic temperature variability on a multi-decadal time scale.
AMO actually seems to affect many things outside the Arctic as well
eg Temperatures at Armagh in Ireland
Grape harvesting in Portugal
retreat and advance of Swiss glaciers
Even the glaciers in the USA NW seem to be affected.
As well as the raw measured temperatures in the US
Even South African temperatures have the same pattern !
The continued arctic sea ice decline is NOT solely because it is influenced by the low phase of any cycle – the warming effects in the arctic are additional to cycles operating there.
Things have moved quickly in the last 5 years too: temperatures in Svalbard, Siberia and N Greenland show this.
..
IS A MYTH or a BLATANT LIE.
There has been no Arctic sea ice decline since around 2005
NSIDC NH is currently above the 15 year average.
And FAR ABOVE the Holocene norm.
Your Norwegian Blue impression is quite bizarre, mindless parrot.
.
You have ABSOLUTELY ZERO EVIDENCE to back up that fallacy.
Much of Siberia, and Greenland are currently BELOW the 1979-2000 average
Siberia?
https://www.rt.com/russia/510740-central-siberia-record-cold-december/
Climate Reanalyzer has current Arctic anomaly at -1.4ºC
After the effect of the 2015-2016 big blob/El Nino event, Arctic temperatures are nearly back down to the ZERO TREND from 2000-2015
It is pretty PATHETIC to have to rely on that El Nino effect to try to make a pointless point.
Both the Polyakov-based graph in the article above and the HadCRUT4 Arctic (70N-90N) monthly surface air temperature anomalies indicate similar overall Arctic long-term cyclical trends.
But at least data from some individual stations can keep one’s spirits up in the cheery hope that the world is heading for a climate catastrophe.
A record high (by a few tenths of a degree) on one day is all griff needs to prove that the arctic is MEEEEEEELTING.
Ice levels in the arctic are about the same as they were 5 years ago and well above what they were 12 years ago.
The phases and cycles of the oceans are leading the temperatures, the phases and cycles of the sun are leading the ocean cycles :|| (period)
So tell us, griff, when the Arctic is really going to be ice-free. Despite the scientific forecasts, it didn’t happen in 2013, 2014, 2015, 2016, 2018 or 2020.
https://cei.org/blog/wrong-again-50-years-of-failed-eco-pocalyptic-predictions/
https://wattsupwiththat.com/2020/12/18/wrong-again-2020s-failed-climate-doomsaying/
I love this gem in the “cooling/heading for a new ice age” predictions – “Increased frequency and amplitude of extreme weather anomalies such as those bringing floods, snowstorms, killing frosts etc.”
ROTFLMAO
”Things have moved quickly in the last 5 years too”
Stop worrying. We are at the peak of two different cycles at the moment. The 65, and the 230 year cycles. Within a few years, temps will begin to fall and you will really wish that co2 has the influence the zombies claim. Personally, I’m so glad to have lived during this lovely warm phase.
The cooling has already begun.
I could have sworn that the Arctic included Canada but apparently not! Benevolently ignorant as the saying goes.
The Arctic includes the Arctic Ocean, Greenland, Iceland, and part of Siberia and northern Alaska.
<i>As to the driver for the multidecadal ocean cycles it may well be the solar cycles. Soon (GRL 2005) showed how the Arctic temperatures (Polyakov) correlated extremely well with the total solar irradiance (Hoyt-Schatten) (r-squared of 0.79). </i>
Except that the Hoyt-Schatten reconstruction no longer is considered valid.
Here are some modern series:
https://lasp.colorado.edu/lisird/data/historical_tsi/
Even the last two cycles (23 and 24) on the LASP graph are incorrect:
https://leif.org/research/Calibration-TSI-Magnetic-Flux.pdf
‘As to the driver for the multidecadal (global) ocean cycles it may well be the solar cycles’
The graphs of the solar data reconstructions that you present show that there is a cyclical variation in the strength of the solar cycles that has a period of approximately 10 solar cycles, or 110 years, where as the multi-decadal ocean cycles have a periodicity of approximately 70 years, i.e. they don’t match.
In my opinion the periodicity of the ocean cycles is likely based on the mechanics of the ocean currents.
It must be also be remembered that one of the largest factors that determines the amplitude of any cyclical process is the amplitude of the previous cycle. The way that the solar cycles can affect the ocean cycles will be as an additional forcing, on top of the amplitude that is already embedded from the previous ocean cycle. Thus the effect of the solar cycle, as an additional forcing, on top of the existing ocean cycle, can be very difficult to identify, as it may only be seen as a modification of the ocean temperature cycle. In addition, due to the tremendous heat capacity of the oceans, the effect can be displaced in time by many years (decades).
We see a similar situation with the shorter cycles. The article posted by Willis Eschenbach (https://wattsupwiththat.com/2021/01/26/complete-ensemble-empirical-mode-decomposition/) shows that the ENSO cycle (which is a local cycle) has a relatively stable periodicity that averages about 3.7 years. The periodicity is again likely to be determined by the mechanics of the ocean currents. However previous papers (for example: ENSO predictions based on solar activity, Judith Curry, Sept 1, 2019) conclude that the amplitude of ENSO is affected by the 11 year solar cycle, with a delay of the order of approximately 4 years.
Thus we can see an overall picture of a short-period (3.7 years), local (to the Pacific) ocean temperature cycle (ENSO) driving global atmospheric temperature variations. The amplitude of the ENSO cycle is influenced by the solar cycle (11 years), and also by an underlying global ocean temperature cycle (70 years). The amplitude of this global ocean cycle is in turn influenced by the long term solar cycle – 110 years. And, all of these cycles are characterized by a large degree of internal variability.
I wonder if the climate modellers have adequately accounted for all of these cycles and the interactions between them.
dh-mtl – good pointing out there is non-linear amplitude of cycles by “amplitude of previous cycle.”
Hi doc
And yet the AMO can be very accurately reconstructed by combining two magnetic components in the Earth’s magnetic field, of which 21.4 years is also periodicity of the solar magnetic oscillations ( Hale cycle) and 16.1 years which is due to the ‘jitters’ in the earth’s core differential rotation.
http://www.vukcevic.co.uk/SUN-and-AMO.htm
The AMO has strong input in the Global temperature, and does, as it happen correlates well with decadal changes of the Earth’s magnetic field.
http://www.vukcevic.co.uk/GMF-CT4.gif
One of the important known unknowns : Global temperature v.s.Earth’s v.s. Solar magnetic fields variability (electric currents could be invisibly lurking in the background)
The other day I was listening to yet another let’s say out of the ordinary talks by your Stamford’s colleague, Leonard Susskind ‘the string&holography man’. Keep safe.
Yep, you have done a great job flattening out the solar series. 😉
I will still trust older, non-agenda-driven, reconstructions more, thank you.
You display a nice case of confirmation bias: trusting what agrees with your view
And you bend the data to fit your view.
There doesn’t appear to be a 110 year “cycle” in the data: https://woodfortrees.org/plot/gistemp/plot/gistemp/trend
Of course not, its been INTENTIONALLY ERASED
Hansen and Jones both showed the AMO clearly in NH temperature before hitching a ride on the AGW trough.
HadCrud4 still retains some of the Arctic cyle though
Bethan… You have to understand that GISS fabrication is not worth the paper it is printed on.
It bears very little resemblance to actual recorded data.
” On the other hand a strong and stable quasi 110-120 yearsand ~200-year cycles are obtained in all of these series. “
THE SUB- AND QUASI-CENTURIAL CYCLES IN SOLAR AND GEOMAGNETICACTIVITY DATA SERIES
“Different records of solar activity (Wolf and group sunspot number, data on cosmogenicisotopes, historic data) were analyzed by means of modern statistical methods, including one espe-cially developed for this purpose. It was confirmed that two long-term variations in solar activity –the cycles of Gleissberg and Suess – can be distinguished at least during the last millennium. Theresults also show that the century-type cycle of Gleissberg has a wide frequency band with a doublestructure consisting of 50 – 80 years and 90 – 140 year periodicities. The structure of the Suess cycleis less complex showing a variation with a period of 170 – 260 years. Strong variability in Gleissbergand Suess frequency bands was found in northern hemisphere temperature multiproxy that confirmsthe existence of a long-term relationship between solar activity and terrestial climate”
LONG-PERIOD CYCLES OF THE SUN’S ACTIVITY RECORDED INDIRECT SOLAR DATA AND PROXIES
“Spectral analysis using wavelet, Lomb-Scargle and maximum entropy techniques of the proxy rainfall record of northeastern South Africa based on annual carbon isotope (δ13C) data obtained from baobab trees for the period 1600 AD – 2000 AD show clear evidence of the presence of characteristic solar periodicities. Solar periodicities that were identified above the 95% confidence level include the ~11-year Schwabe cycle, the ~22-year Hale cycle as well as the 80-110-year Gleissberg cycle. A Morlet wavelet analysis of the δ13C data between 1600 AD and 1700 AD shows the effect of the Maunder sunspot minimum on both the Schwabe and Hale cycles during this time.”
Identification of solar periodicities in southern African baobab δ13C record
That you can’t find an 11 year cycle doesn’t mean it doesn’t exist.
It’s even named: Gleissberg cycle, so open your eyes…..
If you are interested to know more about the sun, I recommend you the book above from John “Jack” A. Eddy
Worth reading !
Reykjavik temperatures are a direct match to the AMO
As are Alaskan regional anomalies
Canadian Maritime temperatures
DOE Arctic sea ice
Surface Mass Balance of Greenland
Strangely even the South American Andes seem to follow the same pattern
There is a direct correlation between PDO 30-year warm/cool cycles and global temps trends as can be seen in the following graph:
https://www.woodfortrees.org/plot/hadcrut4gl/from:1850/to:1880/plot/hadcrut4gl/from:1850/to:1880/trend/plot/hadcrut4gl/from:1880/to:1921/plot/hadcrut4gl/from:1880/to:1921/trend/plot/hadcrut4gl/from:1921/to:1943/plot/hadcrut4gl/from:1921/to:1943/trend/plot/hadcrut4gl/from:1943/to:1977/plot/hadcrut4gl/from:1943/to:1977/trend/plot/hadcrut4gl/from:1977/to:2005/plot/hadcrut4gl/from:1977/to:2005/trend/plot/hadcrut4gl/from:2005/plot/hadcrut4gl/from:2005/trend
We’ve been in a prolonged PDO warm cycle since 1977, which is the main reason we’ve had a 0.14C/decade UAH 6.0 warming trend since 1979.
Super El Niño events also cause large global temp spikes, whose effects are mitigated by strong La Niña events.
Since the 2015/16 Super El Niño event, we still haven’t had a strong La Niña event as the current one is only a moderate one, but still, by April of this year, UAH 6.0 will likely fall be 0.0C.
When the next PDO cool cycle starts (nobody knows when), global temp trends will again go negative for the duration of the PDO cool cycle and the CAGW scam will be DOA because CAGW projects a 0.3C/decade or greater warming trend from now until 2100. Not so much…
ECS is likely around 1C, which not only isn’t a problem, it’s a net benefit.
it’s just a waiting game now about when the next PDO cool cycle will restart..
This is understandable when you see the 30 year trailing TSI data (using Greg Kopp data)
This is why I believe Hansen at GISS knew this in the mid-1980’s from data GISS had at the time.
Hansen, being an environmental activist before scientist, wanted to k1ll coal mining, (especially in WV with it mountain top removal mining, and sulfur emissions) realized there was a window of opportunity until about 2010 +/-5 years to claim human CO2 was the primary cause of the coming next 30-35 years of warming and something had to be done to stop it. The birth of the Climate Scam then commenced with his Senate testimony in 1988 and the UN Rio conference that created the UNFCCC in 1992 and with the first IPCC assessment report in 1990.
The only thing saved their butt was the El Nino of 2015-16. It’s all downhill for the next 25 years or so now. They know it. They know they have to close the deal on Global Socialism before the climate scam Trojan horse collapses.
Also, if we flip the NH sea ice and superimpose it on the AMO, we get a very close match
(end date is about 2018)
Central Siberia also follows the same pattern
Gotta put in a plug for one of my favorite college textbooks…
Principles of geomorphology
by Easterbrook, Don J
Now that was along time ago!
This post fits with in with what I posted recently. CO2 is not the cause of warming.
https://breadonthewater.co.za/2021/01/26/am-i-a-climate-denier-denialist/
I don’t think the Vikings grew grapes for wine in Greenland. Vinland was further south on the N. American continent.
How do we find out for sure, I’d really like to know if you can help I’d appreciate it. In layman’s terms please (I am one of the laymen). If the Vikings really did grow grapes on Greenland that would be fascinating. No wonder a certain mann felt compelled to make a hockey stick.
https://www.sciencedaily.com/releases/2018/06/180604151150.htm
Certainly an interesting topic for research..
I am only slightly conversant in the mythology of Vinland, however propose the following interpretation of suppositions about grapes being found. Wild grapes would not be like what we moderns consume.
The plant we call Bearberry in English is certainly found in Greenland-like climates & has not only a range of traditional folk medicinal applications, but smoking the leaves has effects on the mind. Thus, reporting it grow in Vinland would be something relevant – healing & ceremonial buzz.
Bearberry fruit grows in clusters, enough like grapes clusters that the current botanical name is a compound of the word “-staphylos”, which is borrowed from the Greek to mean resembling a bunch of grapes. Obviously Vineland retellings didn’t employ Greek terminology but adventurers certainly knew of the useful bearberry plant, some what it looked like & in their language conceivably had a name for it.
I propose proponents of the legend wanted their audience, who were not all herbalists/ethno-botanists, to grasp the image that a known valuable clustering plant was found in Vinland. My impression is that the desired alcoholic beverage of Norse folk was not wine & they would not make finding grapes of major importance; I suspect the translation “Vin-” is due to outsiders’ appellation for comprehension rather than the original word in the speakers language popularly used for what we now call Arctostaphylos uva ursi (in English called bearberry).
Brian Fagan in his book ‘The Great Warming : Climate Change and the Rise And Fall of Civilisations’ says (page 91)
“Leif Eirikson, the son of Eirik the red, ….then coasted southward….until he reached the mouth of the St. Lawrence River, then southward to a region south of the great estuary that he named Vinland, on account of the wild grapes that grew there. He founded a small settlement at L’Anse aux Meadows on the northern peninsula of what is now Newfoundland”
You are right.
Ice thickness INCREASING around Svalbard
https://www.unis.no/2020-a-good-sea-ice-year-in-svalbard/
Actual weather patterns suggest the same for this year. Winds are not from the SW but from the NE: see for now and the coming days: https://www.ventusky.com/?p=45;27;1&l=snow&t=20210207/1800&m=gfs
In recent years many low pressure systems came from the SW and turned around Norway on the north. Right now they are blocked and go southward to Danmark. A different pattern is bringing colder weather to Western Europe. If a high pressure system will develop over Scandinavia old fashioned ‘skating winters’ will return: eastern winds will bring ‘Russian cold’ to Western Europe. We will see what we get at the end of this winter and next year. Actual weather patterns are quite different from what I have seen most years in the 2000s. Cold February 2012 has been an exception, this seems to be more persistent as last year’s developments in the North Atlantic seem to be continued.
https://en.wikipedia.org/wiki/Early_2012_European_cold_wave#:~:text=The%20early%202012%20European%20cold,much%20of%20the%20European%20continent.&text=Particularly%20low%20temperatures%20hit%20several,44.9%20%C2%B0F)%20in%20Finland.
I like all the interesting research here. But I have to wonder if Nature is so well ordered that it can be expressed in cycles. My experience is that Nature can be both messy and surprising when it wants to be. 😉
Think of it as being chaotic, on top of chaotic cycles. 🙂
Yes. The ‘cycles’ is just a language to explain the broader patterns, doesnt mean a natural system will follow ‘our rules’
If you have multiple cycles one on top of the other, and all with varying amplitudes and frequencies, and all influencing the each other, you get what appears to be chaos. That’s why it’s easier to just blame the great sky dragon and use that to advance your particular political aspirations. Religion in other words.
Not quite correct. There are glaciers on every major landmass and many islands in the Atlantic sector from Davis sound east to Severnaya Zemlya. There are very few glaciers in northern Siberia, and none near the coast.
In the rest of the Arctic from Taimyr east to Bering Strait and on through northern Alaska and Canada including most of the Parry Archipelago there are NO glaciers (except a few far inland in the Brooks Range). This area is very cold but too dry for glaciers to form.
Glaciers require moisture which comes into the Western Arctic from the Atlantic ocean. The Pacific contributes little moisture since it almost all rains/snows out on the mountains of Southern Alaska and Sikhota Alin and Chukotka. Hence no glaciers in the Eastern Arctic.
“Arctic temperatures (Polyakov) correlated extremely well with the total solar irradiance (Hoyt-Schattem)”
Yet the AMO is always warmer at least during each centennial solar minima. Like in the Oort solar minimum from around 1000 AD which gets mislabeled as the Medieval Warm Period, and the super solar minimum of 1250-1195 BC which gets mislabeled as the Minoan Warm Period. That’s when the Minoan civilisation collapsed.
The most recent three coldest AMO anomalies in the early-mid 1970’s, mid 1980’s, and early 1990’s, correlate extremely well with the strongest solar wind states of the space age observations of the solar wind. And the decline in solar wind strength since 1995 with AMO warming since then. Take a look at the collapse in the solar wind strength late 1976 which switched the multi-year La Nina over to El Nino in the great Pacific climate shift. And the annual detail of slightly stronger solar wind states during AMO cooler anomalies 2000-2003, 2013-2015 (the cold blob) and in 2018. And El Nino conditions normally increase during centennial solar minima, because an increase in negative NAO/AO conditions.
There is also a linkage from ENSO to the AMO, with major AMO warm pulses occurring around 8 months after the December peak of El Nino episodes, like in Aug 1998, Aug 2010, Aug 2016 etc.
You are confusing the general collapse of Bronze-age societies in the Eastern Mediterranean c. 1190 BC with the collapse of the Minoan which occurred c. 1450 BC.
LMIIIB was 1350-1100 BC
“The sea ice extent diminished following the Great Pacific Climate Shift (flip of the PDO to positive) in the late 1970s. It stayed relatively stable until early 2000s when a more precipitous decline began, related to a spike in North Atlantic warmth and a positive AO.”
That’s backwards, at multiple points, the sea ice extent is reduced with negative NAO conditions. In 1981-82, 1985, 1988-89, 1993, 1995-1999, and 2003-2013. It’s not just that negative NAO drives a warmer AMO, -NAO also allows more warm humidity events and cyclones into the Arctic.
“Note the current interglacial period ice core data tells us the last 10,000 years shows 1000-year cycles.”
Grand solar minima series occur on average every 863 years, and every fourth series at 3453 years shows up stronger in the GISP2 series. Most of the warm spikes fit that interval, and most notably, it is the time between the three coldest anomalies around 6200 BC, 2700 BC, and the 700’s AD. But don’t eyeball the GISP2 chart in the post here as its time scale is not linear.
I am convinced that the 8.2kyr event was warm in the mid latitudes like 2750-2450 BC and the 700’s AD were (see Esper 2014 for the 700’s AD). There were lots of expansions of village settlements then, in the Indus region, in Serbia, and wheat growing and an early boatyard in southern England. Plus the 8.2kyr event was dominated by strong trade winds, which means positive NAO conditions, and global La Nina impacts. Greenland should get colder with a strong positive NAO regime.
Time to bring back an old idea? A dam across the Baring Strait.
https://link.springer.com/referenceworkentry/10.1007/978-3-319-24237-8_142
Cite this entry as:
(2016) Dam in the Bering Strait. In: Zonn I.S., Kostianoy A.G., Semenov A.V. (eds) The Eastern Arctic Seas Encyclopedia. Encyclopedia of Seas. Springer, Cham.
Seems the Baring Strait is quite shallow, unlike the underwater ridge between Iceland and Norway.
Very interesting.
A refreshing draught of real climate science and oceanography, thanks Joe!
From the article: “Greenland data suggests the recent warming falls far short of earlier warming periods during the current interglacial and short of the warming early in the 20th century.”
Great article and lots of good comments showing it was just as warm in the past, even the recent past, as it is today.
This means CO2 is not necessary to account for the current warming of today. Mother Nature is in control. She warmed the past in the same way She is warming the present. CO2 was not involved in past warming enough to matter, according to the IPCC, so there’s no reason CO2 has to be involved today to reach our current level of warming.
The Written Temperature Record says CO2 is not a problem for humanity. It shows there is no unprecedented warming going on today, contrary to Alarmist claims.