Ice Age Temperatures and Precipitation Reconstructed from Earthworm Granules

New method for determination of past climate data on land applied comparatively for the first time / Ice Age summers in Central Europe were at times warmer than previously known.

Peer-Reviewed Publication



New method for determination of past climate data on land applied comparatively for the first time / Ice Age summers in Central Europe were at times warmer than previously known

Scientists from an international research project led by Johannes Gutenberg University Mainz (JGU) have applied a new method to reconstruct past climate. As they report in the current issue of Communications Earth & Environment, they have determined temperatures and precipitation during the last Ice Age, which peaked about 25,000 years ago, by analyzing earthworm granules. “The new method was discovered at Université Paris 1 Panthéon-Sorbonne and further developed at the Max Planck Institute for Chemistry,” said Dr. Peter Fischer of JGU’s Institute of Geography, who was the lead investigator of the TerraClime project funded by the German Research Foundation (DFG) in which the study is embedded. “In cooperation with other scientists, including researchers from the University of Lausanne and Römisch-Germanisches Zentralmuseum, we used the method to reconstruct the climate at Schwalbenberg near Remagen and Nußloch near Heidelberg.” The two sites form well-developed last-glacial dust deposits. The so-called loess contains sequences dating from 45,000 to 22,000 years before present, in which the earthworm granules with up to about only 2.5 millimeters in size can be found throughout. These calcitic granules, technically known as Earthworm Calcite Granules (ECGs), are secreted daily by earthworms. Using the so-called radiocarbon method, which is based on the decay of the naturally occurring radioactive carbon isotope (14C), researchers can precisely determine their age. Additionally, by analyzing the ratios of stable oxygen and carbon isotopes in the ECGs, it is then possible to reconstruct how warm or how humid it was at the time of their formation.

Summer temperatures were higher than previously thought and humidity was significantly reduced

“Analysis of the data obtained from the ECGs shows that from 45,000 to 22,000 years before present it was much drier in Central Europe than it is today, with up to 70 percent less humidity,” said Dr. Charlotte Prud’homme from the University of Lausanne, the study’s lead author. “This allows us for the first time to quantify previous findings about this period.” The novelty in these investigations on ECGs is that summer temperatures at the time were significantly higher than previously thought. “Although summers during the cold maximum of the last glacial were about four to eleven degrees Celsius colder than today, they were only one to four degrees below the values of short milder climatic phases that occurred during the last glacial,” explained Fischer. “Given these summer temperatures, we cannot exclude that Ice Age human populations may have made a seasonal living in Central Europe during the cold maximum, at a time for which it is generally assumed that humans could not survive here,” added Dr. Olaf Jöris of Römisch-Germanisches-Zentralmuseum, who was also involved in the study.

“Until now, reconstructions of Ice Age climate have been mainly based on the analyses of microorganisms in deep-sea deposits,” stated Fischer. For the continents, corresponding comprehensive data have been lacking so far, which can be changed with the new method: “Since ECGs can be found in many loess sequences, temperatures and precipitation of the past can now be determined on land over a large area. One main aim is to build a database that can be used to precisely quantify past climate changes on land and to identify force feedback mechanisms. Incorporating land-based climate data will increase the database and contribute to improve existing climate modelling and thus provide valuable insights for future climate change.”

The German Research Foundation funded the TerraClime project including the ECG dating with around EUR 400,000.

Related links: – DFG project “TerraClime” ; – DFG project for the dating of the ECGs




Millennial-scale quantitative estimates of climate dynamics in central Europe from earthworm calcite granules in loess deposits



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November 22, 2022 2:15 am

They study ancient earthworm poop? Oy vey!!


Bryan A
Reply to  Bob Tisdale
November 22, 2022 5:16 am

It’s a crappy job but someone’s gotta do it

November 22, 2022 2:31 am

and Id bet that info was already known, and proved by a far less obscure supposed a geologist..but they got some nice funding and felt “special” doing this

Reply to  ozspeaksup
November 22, 2022 8:24 am

“Peer-Reviewed Publication”

Reply to  n.n
November 22, 2022 4:28 pm

Those of like minds scratching each other’s backsides for recognition. You scratch mine and I’ll scratch yours…

Reply to  johchi7
November 23, 2022 3:17 am

That’s not all they’re scratching….

Matt Kiro
November 22, 2022 3:16 am

Wait, vast amounts of water were frozen as ice, and they seem surprised that humidity was much lower than they previously guessed.

Sometimes it seems these researchers have no previous scientific knowledge and are just trying out formulas they found in their chemistry book

michael hart
Reply to  Matt Kiro
November 22, 2022 12:20 pm

Yes, I was curious about the statement  “ analyzing the ratios of stable oxygen and carbon isotopes in the ECGs, it is then possible to reconstruct how warm or how humid it was at the time of their formation.”

So what are they claiming. Warmth or humidity? Are they making an assumption that the two are necessarily correlated?

Reply to  michael hart
November 22, 2022 7:30 pm

They dont hold hold back, them claim both!
We make use of a singular material for quantitative, high resolution palaeoclimate reconstruction from loess sediments, which can be analyzed not only as palaeothermometers44 and palaeo-rainfall gauges….

Lots of computer modelling seems to fill in the gaps, a word search for ‘model’ in the paper gets 50 hits

Reply to  Duker
November 23, 2022 3:18 am

Thanks, interesting map.

Reply to  Matt Kiro
November 22, 2022 7:17 pm

It was well known that Ige Ace was much drier- less rainfall, and by extension less humidity.

Peta of Newark
November 22, 2022 3:35 am

The Emperor is very dapper this morning – where did he get those gorgeous rags?


  • What were those temperatures compared to then and now…
  • How does your Carbon Oxygen proxy technique actually work…
  • (Notta lotta confidence is instilled with a wide error band of 4 thro 11 Celsius)
  • What is your adjustment for the ‘now’ temps, considering that:
  • a/ The Romans trashed most of Europe and made it desert
  • b/ There are some humongous urban heart islands on Europe right now
  • c/ There are some even more humongous Rural Heat Oceans created by ploughs, deforestation (big thanks hugs & kisses for Henry 8th), Ammonium Nitrate and Glyphosate

So you found some stuff made by earthworms. Very nice (I really do mean that this time)
I think we’re safe in assuming that The Worms were alive, well and had plenty to eat. Organic ‘stuff’ created by plants.
Thus The Plants were alive, well and growing.
In turn, the soil bacteria were alive, well and thriving.
By reference to the fridge in your kitchen, the soil temperature must have been above 5 Celsius – else the bacteria simply ‘stop’ and when they stop, everything else stops.

Add all that together and as we’re doing Climate Science, throw in some random trivia, wild exaggeration and a sprinkle of simple speculation….

  1. Was there even an Ice Age in the first place?
  2. Considering all the changes (mentioned above) how does this work bear any relevance to either today’s ‘climate’, let alone tomorrow’s?
Reply to  Peta of Newark
November 22, 2022 4:51 pm

Simple logic would indicate that during summer months as heat from the sun around the equator warmed that snow melted and ground thawed to where the frozen worms far below became active in the muddy earth and took the time to relieve themselves as they bored their holes. As fall came the ground cooled, so, the worms dug deeper as the ground froze as winter came to repeat the cycle as the eggs warmed and hatched. We see this going on today where temperatures fluctuate doing the same thing. That carbon dating these worm’s crap is logical to period stamp that warming between the glacier and equator occurred through summer months.

Ron Long
November 22, 2022 3:36 am

Maybe. If they say, paraphrasing, summers were not as cold as thought, could they also say winters were colder than thought? Could they make a comparison to todays climate? Here’s a clue, Russian dissidents were sent to Siberia, not the Black Sea.

November 22, 2022 3:46 am

I suppose it kept them off the streets for a time.

up to 70 percent less humidity

Had they bothered to check Antarctica they’d have found that the relative humidity of air at the South Pole is often as low as 0.03%

What a giveaway

Jeff Alberts
Reply to  strativarius
November 22, 2022 7:54 am

Yup, largest desert on the planet.

Joseph Zorzin
November 22, 2022 5:05 am

“by analyzing the ratios of stable oxygen and carbon isotopes in the ECGs, it is then possible to reconstruct how warm or how humid it was at the time of their formation”

I’ll have to read more about this science. Maybe it’s very good- maybe not. There may be good logic to it- but how accurate is it? How warm OR humid? Can it do both? Really?

The “scientists” say they can tell SO much from tree rings- but that I don’t believe.

Reply to  Joseph Zorzin
November 22, 2022 5:36 am

Interestingly, a proxy is usually the “authority or power to act for another“. In this case it is supposedly representative in some way of the preserved physical characteristics of the environment that can stand in for direct measurements. 

But is it really any better than extrapolation? I would expect someone like M.E. Mann to say it is. Look what he could do with just one tree – oh, and a nature trick.

Reply to  Joseph Zorzin
November 22, 2022 6:58 am

Another proxy to add to the proxy spectrum with its inconsistent and often conflicting range of 2.5 C since the ice age…so actually not very useful although much is made of them.

see the source for which colored line represents which proxy, the emphatic black line being a dubious average of those diverse values.

comment image

Jeff Alberts
Reply to  DMacKenzie
November 22, 2022 7:56 am

Yeah, but all you have to do is average them all together, and then it’s magically “right”. Just like averaging a bunch of temp readings from all over the world.

Or maybe not.

Ireneusz Palmowski
November 22, 2022 6:33 am

Earthworms are extremely sensitive to frost because they contain a lot of water. In addition, they coexist in symbiosis with soil bacteria. They form cocoons of cellulose (carbon). To survive the winter, they need to hide in an area that does not freeze, and there they hibernate.

Reply to  Ireneusz Palmowski
November 22, 2022 7:20 pm
They are obligate inhabitants of glacier ice (they cannot live anywhere else). In fact, their bodies are so specifically adapted to this cold, harsh environment that they “melt” at room temperature due to liquefaction of their cell membranes.

Ireneusz Palmowski
Reply to  Duker
November 23, 2022 3:11 am

Lumbricus terrestris is a deep-burrowing anecic earthworm,[3] that is, it builds deep vertical burrows and surfaces to feed, as opposed to burrowing through the soil for its food as endogeic species. It removes litter from the soil surface, pulling it down into the mineral layer, and deposit casts of mixed organic and mineral material on the soil surface.[3] It lives in semi-permanent burrows and can reside in or escape to deeper soil layers.[4]
Its activity is limited by temperature and humidity. High soil and night air temperatures inhibit activity, as do low night moisture and dry soil. During such times, particularly in the summer, the worms will retreat to the deepest parts of their burrows. Winter temperatures can also reduce activity, while activity in maritime climates can continue through winter.

Sweet Old Bob
November 22, 2022 6:57 am

“One main aim is to build a database that can be used to precisely quantify past climate changes on land and to identify force feedback mechanisms.”

Really ???
” Where’s my money ?”

Jeff Alberts
Reply to  Sweet Old Bob
November 22, 2022 7:57 am

Databases cost literally nothing to build, except time.

Reply to  Jeff Alberts
November 22, 2022 12:56 pm

But time is money, unless you work for free.

November 22, 2022 7:00 am

How did they verify the calcite granules had remained closed systems within the loess?

Jeff Alberts
Reply to  Antoine
November 22, 2022 7:58 am

We don’t need to show you no steenkeen verification!

Joseph Zorzin
November 22, 2022 7:31 am

I happen to believe that aliens are visiting Earth and that many of the UFO sightings are real- having seen one myself in 1983 along the Taconic Parkway in NY state- a location of numerous sightings through the ’80s. Of course there is as of yet no proof so maybe it’s not true- I’d just like to think it’s true. The point I’m getting to is: many people think aliens have been here for a very long time- perhaps thousands or millions of years. One reason I’d like them to be here is that perhaps they have scientists who have kept track of the Earth’s climate all that time. I’d love to see the look on Mickey Mann’s face if an alien says that the climate hasn’t changed much in recent centuries and there is no climate emergency. If in fact they’ve been here for ages, they might have some fascinating histories of the human race and our civilizations- with photos of early humans going back to Australopithecus. Along with photos of famous people long before humans invented cameras. I can dream, can’t I? Among others- I’d like to see a photo of Cleopatra. And maybe of Jesus- though I’m an atheist, I think he probably did exist.

Jeff Alberts
Reply to  Joseph Zorzin
November 22, 2022 7:59 am

UFO sightings are real”

That statement is pretty meaningless.

Joseph Zorzin
Reply to  Jeff Alberts
November 22, 2022 8:06 am

I didn’t say they are real- I said I believe they are real and I also said they may not be. So, your comment is pretty meaningless.

Jeff Alberts
Reply to  Joseph Zorzin
November 22, 2022 9:32 am

No, my statement was correct.

By saying “real”, whether you add “believe” or not, says nothing. Real what? You see something in the sky you can’t identify. So what?

Neil Jordan
November 22, 2022 7:51 am

First, there were treemometers. Now there are wormometers.

Jeff Alberts
Reply to  Neil Jordan
November 22, 2022 7:59 am


Robert B
November 22, 2022 11:39 am

I know that “ice age” automatically conjures up a conclusion of very cold, but as we have seen in NY, formerly glaciated areas still get a lot of snow during the interglacial.

The climate probably was colder because of the higher albedo, but despite the strong feedback, the glacial period ended quickly. It can’t be understood by, amateurishly, putting it down to changes in global temperature. Rainfall must have been an important factor in melting the ice in the warmer months.

Reply to  Robert B
November 22, 2022 2:33 pm

Looking at the ocean south of Greenland now gives a hint at why glaciation comes to end. The pool of water just south of Greenland, where the glacier calves, is the only ocean water in the northern hemisphere where the ocean surface is cooling.

Now imagine when there are ice mountains all the way down to 40N over all the land north of 40N and all those glaciers are calving into the northern oceans. The ensuing cold water slows down the water cycle over the northern land masses and snowfall gets overtaken by snow melt.

The “global warming” currently being experienced is the start of the current glaciation. It is in the transition phase but Earth is past peak melt. Permanent snow cover on Greenland has been increasing throughout the satellite era.

Snowfall on the western side of USA is also increasing but so far melt is mostly outpacing snowfall – 100 years at Mt Ranier:
comment image:

The growing heat in the northern oceans will drive glaciation as the tropical heat gets transported by ocean and air currents toward the North Pole – per attached. Those yellow streams and eddies in the North Pacific and North Atlantic are major ocean currents bringing warm water toward the pole to feed the winter evaporation that produces snow.

Screen Shot 2022-11-22 at 3.56.32 pm.png
Last edited 4 months ago by RickWill
Reply to  RickWill
November 23, 2022 3:23 am

Thanks. Both Russia and Canada/Alaska are currently near 100% snow-covered.

November 22, 2022 1:04 pm

The attached image depicts the northern hemisphere temperature in January. Any location blue to maroon is below freezing.

This single image is the essence of Global Warming. The MINIMUM surface temperature of all the land north of 40N is increasing at almost 4C per century.

This is at a time of the year when there is next to no sunshine so that rising winter heat is directly related to increasing snowfall – the REAL 100kyr winter for all the land shaded blue to maroon has started. Earth is now past peak melt.

Snow melt is no longer outpacing snowfall on an increasing proportion of Greenland despite the warmer ocean Water to the east and west of the island.:
comment image
Greenland is now approaching permanent snow cover over the entire island.

All existing land will have lower moisture level when the ocean level falls at the peak of glaciation because it is at greater elevation with respect to sea level. The ice mountains will have be extremely low moisture levels just like Greenland and Antarctica now.

Screen Shot 2022-11-22 at 1.10.57 pm.png
Last edited 4 months ago by RickWill
November 23, 2022 3:12 am

Analysis of the data obtained from the ECGs shows that from 45,000 to 22,000 years before present it was much drier in Central Europe than it is today, with up to 70 percent less humidity

The message of this is that cold is bad. Very, very bad. Therefore, warm is good. Then why are these marxies trying to make things colder?

Last edited 4 months ago by beng135
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