These much warmer Greenland temperatures imply that the elevation of the ice sheet was 400 meters lower than it is today from about 6,000 to 10,000 years ago.
Scientists (Westhoff et al., 2022) report that the two largest Greenland melt events in the last few hundred years occurred in 2012 and in 1889 CE – when atmospheric CO2 levels were still under 300 ppm.
The “melt events around the Holocene Climate Optimum were more intense and more frequent” than has been observed during the modern period. And the most prominent melt events of the last 10,000 years centered around the Medieval Warm Period, 986 CE.
Overall, the elevation of the Greenland ice sheet has grown by 0.4 km since the Early Holocene, as “summer temperatures must have been at least 3 ± 0.6°C warmer during the Early Holocene compared to today.”
14 responses to “New Study: Greenland ‘Must Have Been At Least 3°C Warmer’ Than Today During The Early Holocene”
[…] New Study: Greenland ‘Must Have Been At Least 3°C Warmer’ Than Today During The Early H… […]
The Holocene Climate Optimum is a good period to study because it is the only period in the past 20,000 years with strong evidence that the world was warner than in the past decade. But the CO2 level was lower, so plants are happier with 400ppm+ today. In my opinion, the current climate is the best climate for humans, animals, and especially plants, since that Optimum ended about 5000 years ago.
We should be celebrating the current climate.
There must be a good reason Greenland was called Greenland rather than
North Iceland or Coldland
“Overall, the elevation of the Greenland ice sheet has grown by 0.4 km since the Early Holocene” A reasonable conclusion can be that we are heading for the next ice age…….
[…] New Study: Greenland ‘Must Have Been At Least 3°C Warmer’ Than Today During The Early Holocene […]
“And the most prominent melt events of the last 10,000 years centered around the Medieval Warm Period, 986 CE.”
And likewise, the Little Ice Age was much colder than today.
Both occurred when CO2 levels were 45% lower than today…And need I recall that the Medieval Warming Period was GLOBAL and not an isolated, regional event.
CO2 is not a climate driver. Except fr the very early stages of Earth history, CO2 levels have negligible, if any influence on global temperatures.
Behind your wikipedia link: “Climate proxy records show peak warmth occurred at different times for different regions, which indicate that the MWP was not a globally uniform event.”
Manmade CO2 is a greenhouse gas and a climate driver
CO2 levels have unknown effects on the climate
More CO2 should impede Earth’s ability to cool itself by an unknown amount
That unknown amount has not harmed anyone in the past.
Manmade CO2 is a gas and not physically shown to be a climate driver
There, fixed that for ya!
I think “notrickszone” has misinterpreted the results of the study:
“elevation of the ice sheet was 400 meters lower than it is today from about 6,000 to 10,000 years ago.” is NOT true.
Ice sheet was (6000-9000 yrs ago) 400m HIGHER than today. Research says:
“Today, the highly dynamic EastGRIP site is 170 km further north-northeast and 400 m lower than 9000 years ago.”
After all, the study was about melting of ice, not gaining of ice. Greenland summer temperatures were warmer than today, but overall and global mean temperature was not. “…while the annual mean temperature remained lower
and gradually climbed to today’s value, more or less following atmospheric CO2 concentrations”
You may want to correct that, thank you.
The paper says: “Using the lapse rate estimate of temperatures decreasing by 0.6 to 0.9°C every 100 m of elevation gain we can deduce a temperature change…of 2.4 to 3.6°C”
If the ice sheet elevation gain is 100 m for every ~0.75°C of cooling, and if it has cooled 3°C since the Holocene peak, then the elevation has risen by 400 m as a consequence of the 3°C cooling.
Hello, I think we were both in error here. I read more carefully and now it seems that the altitude change they are talking about, is not about the present ice surface level (from sea level) but the drilling site. EastGRIP’s vertical drilling hole was 9000 years ago in different place: 170km southwest and 270m (400m) higher. 170km southwest is towards higher “ground”, Greenland is higher from the middle and ice sheets travel or flows down to coasts. So the elevation what we are talking here, is the elevation of the drilling place, not the elevation of Greenland ice surface growing or diminishing 400m from present.
In the quoted part You provided: Elevation gain means when we go backward 9000 years and on that time temperature is decreasing from 0.6-0.9 celsius every 100 meter. This interpretation gets ratification from this conclusion (page 13):
“With a corresponding lapse rate of
0.6 to 0.9 ◦C per 100 m, the temperature has increased by
3 ± 0.6 ◦C over the past 9000 years”
It seems that summers were about 3c warmer in early holocene, but then temperature got more stable or cooled little bit (page 16)
“The trend in the Middle and Early Holocene appears
to plateau, with some fluctuations. This climatic interpretation fits well with the generally accepted theory that summer
temperatures decrease throughout the Holocene”
Also, researhers say, that 3 celsius temperature change is due to “When ice flows downstream, the site elevation decreases and the temperature
gradually increases (see the “Discussion”)” Page 18. It is colder in higher altitudes. Researchers also say, that mentioned 3c change cannot be done by climate.
“This temperature change
is solely connected to the drop in elevation and not any climatic changes” (page 13) but still they connect it to more intense melting layers.
Anyway, this study does not imply modern era global warming would not be human-caused. Or say that present whole ice surface of Greenland was 9000 years ago 400 meter lower than today. Ice surely has been cumulating in some centuries, but I doubt this much.
I would suggest the study indicates that there is nothing unusual about what has happened on Greenland (i.e., cooling since the early 2000s per here and here).
When it comes to Greenland ice sheet melt attribution, any contribution from anthropogenic climate forcing is still “too small to be detected”.
Greenland also cooled from the 1940s to 1990s.
This study suggests there is substantially more ice on Greenland today than during the Early Holocene.
And this study (Fig. 1) indicates there is more ice volume on Greenland today than any time in the last 10,000 years with the exception of a few Little Ice Age centuries.
So this new study is no more than an add-on to these (and many other) studies indicating there is nothing unusual happening today on the Greenland ice sheet that has not occurred naturally and without human intervention.
I will not argue against that Greenland’s ice has melted and refroze many times in million of years. Natural variability.
Non of these articles you provided, deny Greenland’s present melting. Only you do.
”…anthropogenic climate forcing is still “too small to be detected”.”
→ This is old information. Human contribution is estimated now to be 50%, https://www.sciencedaily.com/releases/2014/05/140507132657.htm
”Greenland also cooled from the 1940s to 1990s.”
→ Ok, since Greenland has a nonlinear response to warming, it’s reasonable to assume there are some cooling events, or slowdowns of melting.
If you find a research which says Greenland is gaining ice NOW, I’m happy to read. And btw, instead of
hand picked pictures. A real link to actual research would be nice.
”So this new study is no more than an add-on to these (and many other) studies indicating there is nothing unusual happening today on the Greenland ice sheet that has not occurred naturally and without human intervention.”
→ So past climatic circumstances tells us there is nothing to worry: all is natural variation. Wrong.
We are influencing to the precent melting thorough warming the climate.
Scientist are studying Greenland’s climatic past to understand how it will respond to increasing temperatures. How the ice will melt in hundreds of years. And that is a problem through rising sea level and perhaps messing with AMOC
And you were wrong about 400 meter ice sheet elevation. Greenland gained more ice, but that particular research did not say what you claimed it said. So there is still a demand to correct your headline in the name of the credibility of this website. Thank you.
And commenting my own comment: I was wrong. The issue was not about present surface elevation, but drill hole location.