Traces of ancient rainforest in Antarctica point to a warmer prehistoric world

Imperial College London

Illustration of the Antarctic rainforest  Credit: Alfred-Wegener-Institut/James McKay

Illustration of the Antarctic rainforest Credit: Alfred-Wegener-Institut/James McKay

Researchers have found evidence of rainforests near the South Pole 90 million years ago, suggesting the climate was exceptionally warm at the time.

A team from the UK and Germany discovered forest soil from the Cretaceous period within 900 km of the South Pole. Their analysis of the preserved roots, pollen and spores shows that the world at that time was a lot warmer than previously thought.

The discovery and analysis were carried out by an international team of researchers led by geoscientists from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research in Germany and including Imperial College London researchers. Their findings are published today in Nature.

Co-author Professor Tina van de Flierdt, from the Department of Earth Science & Engineering at Imperial, said: “The preservation of this 90-million-year-old forest is exceptional, but even more surprising is the world it reveals. Even during months of darkness, swampy temperate rainforests were able to grow close to the South Pole, revealing an even warmer climate than we expected.”

The work also suggests that the carbon dioxide (CO2) levels in the atmosphere were higher than expected during the mid-Cretaceous period, 115-80 million years ago, challenging climate models of the period.

The mid-Cretaceous was the heyday of the dinosaurs but was also the warmest period in the past 140 million years, with temperatures in the tropics as high as 35 degrees Celsius and sea level 170 metres higher than today.

However, little was known about the environment south of the Antarctic Circle at this time. Now, researchers have discovered evidence of a temperate rainforest in the region, such as would be found in New Zealand today. This was despite a four-month polar night, meaning for a third of every year there was no life-giving sunlight at all.

The presence of the forest suggests average temperatures were around 12 degrees Celsius and that there was unlikely to be an ice cap at the South Pole at the time.

The evidence for the Antarctic forest comes from a core of sediment drilled into the seabed near the Pine Island and Thwaites glaciers in West Antarctica. One section of the core, that would have originally been deposited on land, caught the researchers’ attention with its strange colour.

The team CT-scanned the section of the core and discovered a dense network of fossil roots, which was so well preserved that they could make out individual cell structures. The sample also contained countless traces of pollen and spores from plants, including the first remnants of flowering plants ever found at these high Antarctic latitudes.

To reconstruct the environment of this preserved forest, the team assessed the climatic conditions under which the plants’ modern descendants live, as well as analysing temperature and precipitation indicators within the sample.

They found that the annual mean air temperature was around 12 degrees Celsius; roughly two degrees warmer than the mean temperature in Germany today. Average summer temperatures were around 19 degrees Celsius; water temperatures in the rivers and swamps reached up to 20 degrees; and the amount and intensity of rainfall in West Antarctica were similar to those in today’s Wales.

To get these conditions, the researchers conclude that 90 million years ago the Antarctic continent was covered with dense vegetation, there were no land-ice masses on the scale of an ice sheet in the South Pole region, and the carbon dioxide concentration in the atmosphere was far higher than previously assumed for the Cretaceous.

Lead author Dr Johann Klages, from the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, said: “Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm. But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in the Antarctic.”


From EurekAlert!

126 thoughts on “Traces of ancient rainforest in Antarctica point to a warmer prehistoric world

    • There’s something to that. It is said that Attila was able to cross a river when he found a ford.

    • Ancient aliens driving Suburbans?

      Ancient astronaut theorists say yes.

      Ancient astronaut theorists, are all of you idiots?

      Ancient astronaut theorists say yes.

    • 90 million years ago?
      When was Antarctica 90 million years ago?
      Now let me look up my tectonic plate map 🙂

      I bet Antarctica wasn’t at Antarctica 90 million years ago!



      • I thought the same thing Roger. I know the plates have moved significantly, but I wasn’t sure of the timeframe. Please post it in comments if you find out.

      • and what about the tilt of the earth. Perhaps Antarctica was as close to the tropics as as Germany is now.

      • As the article states, the paleo location of the sediment core that was collected was “within 900 km from the south pole”, so pretty darn close. You can check out a website that recreates paleo geographic locations at Paleomap Project by Chris Scotese (

      • Here is Scorsese’s famous video

        Antarctica connects with Australia 30-50 Mya. All SH continents (Africa, South America, Australia and India) all converge towards Antarctica and its Southern Ocean separation is lost around 60 Mya when Drake’s Passage closes.

        Greenland together with Europe were on the equator from about 300 million years ago, there should be ample fossil evidence of that.

        I noticed that Britain stayed more or less intact back to 400 million years ago, avoiding getting squashed between Scandinavia and Greenland. At this point the British Isles and the origins of Europe are deep in the Southern Hemisphere. At 430 Mya the British Isles finally “break up” (in reverse, meaning in forward time they came together from several directions).

      • You mean WHERE was Antarctica 90 million years ago. Having rain forests where the sun is absent for 4 months a year sounds weird to me.

  1. If they are saying that entire forests were growing in an area that has 3 months of total darkness and another 3 months of mostly darkness, then this is impossible. The northern most forest is the Lukunsky grove i Russia, but it is still almost 2000km from the north pole. Some plants may grow, but you can not get full blown forests with 3 months of total darkness. I think this says more about plate tectonics. Obviously these parts of Antarctica were in a location that received more sunlight than it does now. That means either the continent was in a different location to what they think, or, Earth’s angle of inclination was far smaller than what it is now

    • ggm, “I think this says more about plate tectonics.” is the correct answer. If you are not a geologist you are now an Honorary one!

      • I had much the same thought that, thanks to Plate Tectonics and Continental Drift, 90M YA that region of Antarctica sat at a lower latitude (likely similar to NZ) and so had constant 24 hour day-night periods allowing for the growth

    • More CO2 allows plants to extend their ranges.

      Antarctic dinosaurs had large eyes. Others migrated.

    • Milankovitch cycles directly affect the amount of solar radiation incident on Earth TOA. The poles would see these cyclic increases and decreases to a greater extent than tropical lattitudes (consider the increase in insolation if Earth’s tilt from the ecliptic reduced down to 0 degrees instead of the current value of 23.5 degrees.

      How much time-averaged insolation would necessary to support a “rainforest” at the South pole?

      • If the inclination reduced to near zero, then there is the answer. At zero inclination (or near), even 90degrees north and south would get sun. Are we sure inclination got to zero ?? That surprises me.

        • I never said that Milankovitch cycles caused Earth’s obliquity to go to zero degrees . . . I said consider what would happen if it did so. Current calculation says that it varies between 22.1° and 24.5° on a cycle period of about 14,000 years. However, resonances with other Milkankovitch cycles could amplify the total increase in polar insolation at times of the 22.1° tilt.

          Also, keep in mind that many plants in temperate latitudes survive 3-4 months of winter dormancy, only to flourish in summer months (in both hemispheres), so 6 months of dim light north of the Arctic circle and south of the Antarctic circle during their respective winters does not necessarily rule out large outbursts of vegetative growth during summertimes . . . acknowledging, of course, that the Arctic really has no land mass underneath its most of its polar ice cap.

    • Stupid question:
      Where was the continent Antarctica 90 mln years ago?
      Certainly NOT at the south pole.

      • The article says the drill site is 900 km from the South Pole. By that standard, Cincinnati, OH is “near” New York, NY.

        But IMO, it’s farther than that from the South Pole, when I look at the Amundsen Sea Embayment. Another article says the site is near the Pine Island and Thwaites glaciers. The PIG is 1660 km from the SP. That’s about 1000 miles, so maybe the author meant 900 miles rather than kilometers.

        But “near the South Pole” sounds sexier than a more accurate location.

      • The Pangaea super-continent was breaking apart about 150 million years ago.
        90 million year ago is about when the Atlantic Ocean began to form.

        • The Central Atlantic was the first part to rift apart, at the Triassic-Jurassic boundary, ~200 Ma. Volcanism from the Central Atlantic Magmatic Province associated with this cataclysmic event has been blamed for the end-Triassic mass extinction event, which paved the way for the rise of dino dominance. They were already becoming dominant in some environments in the Late Triassic, however.

          The Northern and Southern Atlantic opened later.

      • Not a stupid question Alex and there are more than a few of us thinking along those lines. I’m hoping that when someone works it out they can tell us what the location is now for easy reference.

      • As the article states, the paleo location of the sediment core (location of core 90 my ) was collected “within 900 km from the south pole”. They are using plate tectonic reconstructions that have been determined (and there are several versions) based on apparent polar wander paths of major plates. You can check out a website that has plate tectonic recreations at Paleomap Project by Chris Scotese (

    • Surprisingly maybe Antarctica probably hasn’t moved much in the past 100 million years. As with most paleo stuff, there’s some uncertainty. We probably sort of know where the magnetic poles were and probably what the geomagnetic latitude was. The actual latitude not so much, but we still know it fairly well. Here’s a climate map for the Lower Cretaceous — maybe 130 million years ago. and another for the Upper Cretaceous — 70 million years ago? The Scotse site also has paleomaps that show continents and oceans instead of climates.

      I vaguely think that orbital parameters including inclination are pretty solidly known for a couple of hundred million years. But I didn’t look it up.

      I think it quite possible that forests can handle months with no/limited sunlight. My impression is that the modern tree line is determined by Summer temperatures rather than sunlight. But I’m no botanist.

    • ggm
      Axel Heiberg Island at 80 degrees North has similar evidence.
      University of Alberta claims the Island was at same location at time of forests, 6 months of winter. .
      So ?
      Things that make you go hmmm?

    • A)
      Do not use today’s modern forests as the forests 90 million years ago.
      Plants evolve to use and thrive in their environments.

      There are plants that thrive underneath forest canopies in dim light.

      There are many plants that have evolved to enter dormancy for periods of the year.
      Raising these plants requires that plant owners observe these dormant periods, cutting back water, food and often light.

      Using mental images of today’s forests that normally flourish under bright hot sunlight ignores the evolutionary realm available to life. So long as life has access to warmth, light and food when life need it, they will thrive.

      Antarctica has not moved as far as people are implying.
      Ergo, if researchers found evidence of forests, then forests colonized Antarctica. Just not the temperate and tropical zone forests people are familiar with today.

    • ” but you can not get full blown forests with 3 months of total darkness.”

      Not necessarily, consider this example from the northern hemisphere. The following gymnosperms (conifers) are deciduous:-
      Larch (Tamarack ) species
      Bald Cypress
      Dawn Redwood
      Chinese swamp cypress
      Golden larch

      There is plenty of sunlight in the high arctic during the 24 hour long days of summer. The key question is how did the ancient trees survive the 24 hour days of continuous winter darkness?
      One possible explanation for why this disparate group of unrelated conifers are deciduous is that their ancestral forms adapted to growing in the high arctic in the Cretaceous (north of latitude 80 degrees), and that their deciduous habit was a survival tactic to get them through the 3 months of continuous dark during the arctic winter.

      • Good points. Chlorophyll has to be maintained by evergreens during the dormant season, which requires some stored energy & sap flow — difficult in the Arctic. Solution for some conifers? Become deciduous evergreens as you point out. Larch grows further north than just about any conifer. Link about ancient dawn redwood forests in the far north:

        • Deciduous conifers, not deciduous evergreens, since that a non sequitor.

          Larches turn a beautiful shade of yellow before their needles drop.

        • beng135,
          Thanks for the link. Another point to consider is the clear separation in the ecological niches occupied by some members of this group, particularly between the Larch and the Bald Cypress. If the common environmental origin of 3 months continuous arctic darkness is correct then this niche separation can be explained by assuming that the Cretaceous ancestors of the deciduous conifers also occupied separate micro-environments in the ancient forest.

    • Geologists have a very good idea where land masses were 90 million years ago. I don’t think there’s much uncertainty about that.

  2. Where was Antarctica 90 million years ago? It is said that the super continent Gondwana persisted until 180 million years ago. Is it correct to assume these forests were in the dark for four months a year?

      • From the abstract on

        … a temperate lowland rainforest environment existed at a palaeolatitude of about 82° S during the Turonian–Santonian age (92 to 83 million years ago). link

        That surprises me.

        • It’s unclear to me if they’re claiming the site is 900 km from the Pole today or then.

          That is surprising, since Pine Island Glacier is not that far south now.

        • CommieBob,

          Have a look at this paper that studies the flora of the arctic polar regions:

          Abstract: This investigation of the Maastrichtian climate in the Northern Hemisphere is based on taxonomic and ecological studies of fossil floras, leaf physiognomy and the distribution of dinosaurian faunas. Fossil plant evidence indicates that the climate during Maastrichtian time was warm temperate at high and middle latitudes, and subtropical south of 40°N. Precipitation was relatively high (about 700-800 mm) and evenly distributed over the year. The annual range of temperatures was similar to that of modern maritime climates, but the latitudinal gradient was lower than at present. At high latitudes cold-month mean temperatures were about 3-4°C and probably never dropped below 0°C for extended periods. It seems that these comparatively mild winter temperatures in polar regions were a result of the heating of these areas by warm oceanic upwelling.

          Golovneva, L.B., 2000. The Maastrichtian (Late Cretaceous) climate in the northern hemisphere. Geological Society, London, Special Publications, 181(1), pp.43-54.

    • Why did the authors not take continental drift and seafloor spreading into consideration? It’s amazing that this work comes from an institute named after Alfred Wegener, the father of Plate Tectonics.

    • I’d say it was quite a bit farther north than now.
      Even during months of darkness, swampy temperate rainforests were able to grow close to the South Pole, revealing an even warmer climate than we expected. So the earth has cooled more than expected.

      • Look at how much low sea level water is around. The fight for the bottom of the ocean is won by the warm high salinity not the cold dense waters off Antartica today.

        The cold water making the deep ocean conveyor belt is driven by Antarctic cold waters. Previously it was by warm waters pushing down. The warm waters were also allowed to move all around the world allowing warm waters to gather to make a hot humid planet condensing to high salinity waters that sink and make the whole planet warm.

        If we ever want to prevent another ice age we need to blow a large waterway through Panama so the cold waters don’t have as much upwelling along the NA/SA plates and more warm waters on the surface. But that’s a problem for the future peps.

        • Keith,
          How can you say that?
          We only have ten years and a few months . . .
          AOC told us so!
          Indeed Prince Charles told us we had eight years [I think!], about twelve years ago. Or fourteen . . .
          They must be right. They’re famous. So they’re ‘experts’. No???

          /Sarc, mods, /Sarc.

        • Keith,

          I totally agree with your statement.

          The cold water making the deep ocean conveyor belt is driven by Antarctic cold waters. Previously it was by warm waters pushing down. The warm waters were also allowed to move all around the world allowing warm waters to gather to make a hot humid planet condensing to high salinity waters that sink and make the whole planet warm.

          See the concluding statement from my 2013 WUWT essay in support of your view
          The Oceanic Central Heating Effect

          The climatic difference between our modern cold ocean world and the ancient warm ocean world of the Cretaceous is simply due to the presence in the Horse latitudes of shallow tropical seas containing the carbonate ramps that form the planet’s “oceanic central heating system”. The physical location, areal size, and water depth of the world’s shallow tropical seas throughout geological time dictates the quantity of solar energy that these seas can collect from the tropics. Our modern world, with its carbonate platforms and restricted ramps (such as the Persian Gulf) that are sensitive to global sea level fall, has a much less efficient and less robust planetary “oceanic central heating system”.

          In the argument of which comes first: atmospheric carbon dioxide levels or warm ocean water, the geological evidence is unequivocal: The “oceanic central heating effect” dog wags the “atmospheric greenhouse gas” tail.

  3. Dave G

    In have little scientific knowledge but have heard of continental drift.. Is this not a factor?

    • Yup. Stupid Eureka Alert. Antartica was NOT at the South Pole at that time. Just like Svalbard was NOT in the Arctic at that time. See footnote 5 to the Recognition chapter (Wegener and continental drift being theme one thereof) of ebook The Arts of Truth.

        • That would be based on 1cm/yr continental drift, which would accumulate to about 1000 km and the -82 degrees. The more likely value of 3 cm/yr gives between 2500 and 3000 km. That would have put its position at -65 degrees lattitude.

        • who knows how influential ocean currents were at moderating global temps. A temperate environment and plants with large leaves like those living in the jungle under story. But 3 months of darkness? Hard to imagine.

      • Rud Check the scotese site http:// for paleomaps. There are both land/ocean maps and climate maps. The climate maps show the actual sites where climate estimates are available with the (distorted) outlines of the modern continents superimposed. Continental drift is apparent. The Atlantic is much narrower. North and South America are not connected. India is detached from Africa but still thousands of km from Asia. But Antarctic hasn’t moved all that much relative to the pole even as far back as the Lower Cretaceous. If you want the Antarctic well off the pole, you need to go back to the Jurassic.

        I assume they are using magnetic latitudes and best guess estimates of past rifting and motion.

        Are they correct? Who the heck knows. But I don’t see any reason to think their guess isn’t about as good as can be done with what we know today.

  4. Dunno where they got 1000 ppm as prior estimate for Mid-Cretaceous CO2. Previous best guess was 1700 ppm as average for the whole period, with its middle even higher. This was a problem for models assuming CO2 as the causative control knob on climate, rather than an effect of change resulting from real movers.

    • Yep, GeoCarb III model (Berner has it between 1500-2000 ppm (5-7 times pre-industrial) at 110-90 my, and they stress that there are so many variables that come into play when estimating RCO2 for geologic/atmospheric modeling that one can’t assume one process dominates over another.

  5. Surprises in the past but certainty about the present and future. Even a non-scientist knows that knowledge about the natural world is constantly evolving. In a healthy intellectual climate this would be accepted and understood as “new” studies emerge. In our present unhealthy climate of fear this point has to be publicly defended against the worst types of slander. Darkness isn’t just a feature of the past.

  6. ggm April 2, 2020 at 6:18 am
    commieBob April 2, 2020 at 6:25 am
    David Grogan April 2, 2020 at 6:27 am
    As well as Antarctica being somewhere else, the elevated CO2 might be a product of more life and bigger warmer oceans. Now, the study was carried out by very well educated individuals.

  7. “But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in the Antarctic.”

    Look, look, the tail is wagging the dog! (if we use these models)

    • Funny, isn’t it? The measurements show a lower level of CO2 than the models require to produce a temperature that high, therefore the measurements must be wrong.

  8. Another factor over looked is that the earth may not have been tilted. That eliminates the three months of darkness at both poles.

  9. Drift here:

    First of all this region is trendy with alarmists because its a very warm part of Antarctica where things melt naturally, from Volcanoes, Pacific warm weather moving South and the fact part of it is outside the Antarctic circle altogether, sticking out into the oceans that surround it for 10 degrees North from 70 degrees South, so it sounds good for activist scientists to say things are “melting in Antarctica” without qualifying where.

    It seems that Antarctica was in the ‘hood <100 Million years ago, but perhaps a tad further North. However, if their dates are wrong and the remains are older then the growth could have occurred closer to the equator.

    Note in the model that the Antarctica Archipelago is not a continent, its chains of Islands joined by ice, and splits into two bits, the volcanic Western Islands, which are already 30 degree North and well outside the Antarctic circle at Drake's Passage, and the other bit, already on its return journey to the Equator.

    And again, note how the entire heating ia s attributed to CO2 as the cause, which we know is unsupportable a. as the effect is tiny now and diminishes with concentration, so is simply not what causes the warming.

  10. Of course we all know that over the aeons Antarctica has been motoring here and there across the globe, an inveterate tourist.

    • Antarctica 90 Mya was only a bit farther north than now.

      Climate was much warmer then not primarily because of more CO2 in the air, but because oceans were hot, releasing more CO2. Continents were rifting apart, sea floor spreading and volcanism were active.

      Antarctica was still joined to South America, India and Australia by land or shallow seas over continental shelf. The cold Southern Ocean wouldn’t form for tens of millions more years.

      Equatorial currents could span the globe. Epicontinental seas covered much land. It was a Hot House world, at the opposite end from today’s Ice House.

      • As one interested in Gondwanan flora links, the point that stands out apart from what you’ve said so well, is the potential effect of much higher atmospheric carbon dioxide levels on plants that may have allowed them to withstand low-level light for several months each year.

  11. Weird, but facts don’t seem to deter the climate alarmists. Could it all be about something else and not really climate at all??

  12. I was going to comment on the location of Antarctica 90 million years ago but some already commented……the arctic circle has fossils of trees and crocodiles. There is also evidence of snowball earth…not once , but twice. The history of the planet is a series of climate cycles that go on for a time and then something happens and new cycles begin. Today’s climate is about as good as it has been for man – hence the development of civilization.

    • At least three Snowball or Slushball Earth episodes. The second period of low latitude and elevation ice sheets was interrupted by a warmer interval, between the Sturtian and Marinoan global glaciations.

      Since its crust cooled, Earth’s average temperature has fluctuated between perhaps 30 degrees C and -50.

      • There’s a fundamental problem with snowball Earth. Unless Earth’s orbit was significantly different, or the Sun was significantly weaker, there’s no possible way that tropical oceans would be covered in ice. Even if there was a short term nuclear winter from a supervolcano, tropical ice would melt away so quickly that there would be no evidence left behind.

        The direct Sun in the tropics simply can not support the formation of ice, much less it’s persistence across millennia. If snowball Earth is actually true and since the pedantic explanation that it was caused by low CO2 is complete BS that defies the laws of physics, the actual causative influence is completely unknown.

        • The Paleoproterozoic Era Huronian glaciation occurred when solar output was 22% lower than now; the Neoproterozoic Era glaciations when it was more than six percent lower.

          They happen when supercontinents form with land at high latitudes in both hemispheres, plus at the equator. Once ice sheets reach mid-latitudes, they keep growing, due to increased albedo. So it’s down to tectonic plate movements.

          The geologic evidence for low latitude, sea level land ice for long periods during the early and late Proterozoic Eon is overwhelming. In between were the so-called “Boring Billion” years, when supposedly not much happened.

          The issue is whether Earth suffered a Snowball, with sea ice at the equator, or a Slushball, with a band of open ocean at low latitudes.

  13. The position of antarctica and australia (which split off from it ) at 90Mya is well known ;
    The accompanying script from Wiki says:

    -“The South Polar region of the Cretaceous comprised the continent of East Gondwana–modern day Australia and Antarctica–a product of the break-up of Gondwana. The southern region, during this time, was much warmer than it is today, ranging from perhaps 4–8 °C (39–46 °F) in the latest Cretaceous Maastrichtian in what is now southeastern Australia. This prevented permanent ice sheets from developing and fostered polar forests, which were largely dominated by conifers, cycads, and ferns, and relied on a temperate climate and heavy rainfall. Major fossil-bearing geological formations that record this area are: the Santa Marta and Sobral Formations of Seymour Island off the Antarctic Peninsula; the Snow Hill Island, Lopez de Bertodano, and the Hidden Lake Formations on James Ross Island also off the Antarctic Peninsula; and the Eumeralla and Wonthaggi Formations in Australia. “-

    But I am sure David Middleton, as a professional geologist , can give a more definitive account than someone like me who has merely looke d it up on Wiki.

  14. “The work also suggests that the carbon dioxide (CO2) levels in the atmosphere were higher than expected…”

    Bad assumptions lead to bad conclusions. What about the fact that 90 million years ago, Antarctica wasn’t centered on the S pole and ocean circulation patterns were significantly different. What about the fact that we have no idea how the Earth’s orbit has changed over 90 million years or how the Sun may have changed. Given the highly inflated sensitivity the need in order to claim that CO2 is the temperature knob, a mere 1% change in solar energy (3.4 W/m^2) will cause nearly a 3C change in the surface temperature.

    The foolish alarmists consider that nothing ever changes except the CO2 levels they presume drive the temperature. They’re seriously deluded into thinking that the world was exactly perfect at the end of the Little Ice Age that happened to coincide with the start of the Industrial Revolution. They apparently put 2 and 2 together and cam up with 97.

    • They infer the past, speculate about the present, and predict the future outside of a limited frame of reference.

  15. “international team of researchers led by geoscientists from the Alfred Wegener Institute ”

    Wasn’t Alfred Wegener the chap who first postulated continental drift?

    • Yes, and despite all the evidence, his hypothesis lacked a causative agent, so was not embraced.

      After seafloor-spreading was discovered, geologists accepted that he had been right.

    • Yes, Alfred Wegener was the scientific sceptic of his time. He proposed that the continents were moving, although he had no explanation. He was attacked by the concensus scientists because they “knew” that the continents were fixed and unmoving. Of course, we know who turned out to be right in the long run.

      Climate sceptics are in a similar position to Wegener. It is blindingly obvious from the science and the data that global warming is primarily natural (though with a little help from CO2) and also beneficial but they do not have an alternative theory to explain the modern warming. Svensmark is a very good contender, but I’m not sure that, so far at least, he can prove his theory.

      In a sense sceptics don’t need to provide an alternative theory. The modern warming follows an established pattern set by the Minoan, Roman and Medieval warm periods. So, here’s my theory that perfectly explains the modern warming: it was caused by precisely the same thing that caused the previous warm periods.

      The Little Ice Age provides another, very powerful argument that is simple and possibly impossible to disprove with data:
      If it had not been for the modern warming we would still be in the depths of the Little Ice Age. Living in a colder world really would be a catastrophe.

  16. It is very nice that the mentioned researchers found evidence of rainforests existing near the South pole that date back to 118-80 Ma (million years ago), but this evidence is consistent with what climatologists have known for many years.

    The Earth entered the most recent period of “hothouse” conditions (no multi-millennia persistent ice coverage at either pole) at the start of the Permian, about 280 Ma. This condition lasted up to about 30 Ma when Earth begin transitioning into the Quaternary Ice Age, which we are currently in.

    Dr. Christopher Scotese put together a wonderful animation that shows the evolution of land masses (and persistent ice coverage, noted in bright white overlay color) on Earth’s surface from 540 Ma to present, including the subject period. Link:

  17. The Guardian runs this slanted like: look how warm it was then and how cold now, so you see what Carbondioxide does. What the scientifically illiterate editors overlook is that a) the Earth was much warmer overall and b) the Antarctic plate was much closer to the equator when the Gondwana supercontinent broke up.

    • It was a freshwater swamp, if that helps.

      By 92 Mya, the last known temnospondyl (big, amphibian-like tetrapod) was the giant chigutisaurid Koolasuchus, from the Early Cretaceous of Australia, would have already disappeared. It survived until about 120 Mya in rift valleys too cold in winter for pseudosuchians (crocodile-like archosaur diapsids), which normally would have outcompeted them in the aquatic ambush predator niche. Koolasuchus was one of the largest of the brachyopoids, with an estimated weight of 500 kg.

  18. Dawn Redwood (Metasequoia glyptostroboides) grew in the Arctic. I have a 15-yr old near 40 ft tall on my lot now. From Wiki:

    During the Paleocene and Eocene, extensive forests of Metasequoia occurred as far north as Strathcona Fiord on Ellesmere Island and sites on Axel Heiberg Island (northern Canada) at around 80° N latitude.

  19. Does anybody remember when New York State was connected to the U.K. Proven fact! The sea was shorter in the between the 2 & much less deep. So the earth under our feet has moved thousands of miles due to plate tectonics over time & change happens all the time but we don”t see it in our time. Slow and steady is the way the world moves. The Alps or the Himalayas or Appalachians were not born over night. Humanity is nothing in comparison to time.

    • I don’t personally recall 200 million years ago, but yes, North America and Europe were nextdoor neighbors on Pangaea. They remained connected via Greenland for millions of years thereafter, as the Central Atlantic was forming in the rift between NE North America and NW Africa.

      In the Jurassic and even into the Early Cretaceous, North American and European dinosaur genera were similar.

  20. While the evidence doesn’t add up to proof, there has been some evidence the poles may have shifted.

    A possible scenario is that the axis of the Earth at one time ran from Hudson’s Bay (North Pole) to a corresponding pole several hundred miles off Wilkes Land in the south Indian Ocean (South Pole).

    This position of the axis of the Earth would put part of the Antarctic continent in a warmer latitude. A latitude which could support a New Zealand type temperate rain forest and would leave part of Antarctica where it wouldn’t be in total darkness during the winter months.

    Also, if you look at Antarctica, the Wilkes Land side could have less erosion or wear & tear (loosely) and the opposite side seems to have been subject to more erosion over time.

    I suggest the idea plants could survive three months of darkness is difficult to accept.

    A speculative scenario? Absolutely.

    • One speculative hypothesis is that deciduousness (annual leaf drop) first evolved in low light (polar) regimes during the Cretaceous — originally among some conifer genera.

      I must emphasize that is a hypothesis only. It has not been proved or disproved, cannot even be called a theory, and is a current topic of research in paleobotany.

    • Plants survive months of darkness easily, as witnessed by tundra growth. The issue is whether large trees could do so. But we know from high Arctic fossils, and indeed intact logs, that forests of trees did grown there a mere 2.7 million years ago.

  21. Trees in the Antarctic? Temperatures 40, 50, 60 degrees C warmer than now at the South Pole? But, but, but I thought if the Planet got 2 degrees warmer we would pass the Tipping Point and the seas would boil into Outer Space!

    Are you telling me that was all a pile of garbage? That famous NASA scientists and super smart and compassionate politicians were/are full of it? That a Hot House Earth can and did exist without constant hurricanes and forest fires and mass extinction of All Life?

    Well, I never! I was told that the Great Pandemic is just a warm-up for the even Greater Dystopia to be inflicted on humanity to avert the coming Hotpocalypse!

    Are you telling me there’s not going to be a Hotpocalypse? Whoa there!

    Are you telling me that a much much warmer Earth is normal? That a warmer Earth is nicer even, with fancy forests instead of deadly continental ice sheets? That Warmer is actually Better?

    I can’t take it. I’m going back into my mud hut to huddle in the cold and dark and await the End of It All. Warmer is Better indeed! You deniers…

  22. If you go to, you can view Chris’s spectacular animated recreations of plate migrations over the last 540 million years.

    It appears the chunk that became (east) Antarctica drifted between 40S and 60S during mid-Cretaceous 120-80 Mya, so good place to grow rainforest

    I just roll my eyes whenever anyone infers temperature based on estimated CO2 – that is just sooooo backward.

    • GeologyJim,
      Worse than that. They infer CO2 levels from inferred temperature and climate models that no doubt are tuned to an ECS of 4.5 or higher.

      EurekAlert!, defenders of the faith.

  23. If we were to resurrect these tree species today, they could well require a hothouse pumped full of CO2 to survive. Current atmospheric levels are historically low rather than hysterically high.

  24. How could such an ecosystem exist with darkness 24/7 many months each year? Never have I understood that. Ellesmere Island in Northern Canada has the same problem. Light is the problem, more than temperature.

  25. The warmth of Antarctica millions of years ago was not only from global temperature being warmer, but also because Antarctica was in a part of the world that’s warmer than the South Pole. And its warmer location was a contributing factor to the global warmth back then: That made it and its surrounding waters free of snow and ice, or at least free of sea ice and year-round land cover of ice or snow. That means lower albedo and contributes to a warmer world. And without the thick ice sheet that it has now, parts of Central America were under water and that favored more global circulation of ocean water, which would make the temperature of the world more even and the poles warmer. Also, the Bering Strait was wider (due to continental drift) and with deeper water due to higher sea level, and that also favored the Arctic being warmer and the world being warmer.

  26. I worked on a project in the late 90s looking at plant growth at different latitudes. We found that the net primary productivity was based upon sunshine (light flux) and basic growing conditions, ie temperature, moisture, and nutrients.

    The conclusion and the experimental evidence showed that the plants at high latitude grew the same amount, but in a shorter amount of time. For some plants, the lack of a transition to a hot summer, meant they produced more.

    One of the questions that we never answered, which is something I have yet to see, is a way to estimate solar flux if the other quantities are fixed.

  27. CO2 and temperature decoupling at the million-year scale during the Cretaceous Greenhouse –

    We show that pCO2 was in the range of ca. 150–650 ppm during the Barremian–Santonian interval, far less than what is usually considered for the mid Cretaceous. Comparison with available temperature records suggest that although CO2 may have been a main driver of temperature and primary production at kyr or smaller scales, it was a long-term consequence of the climate-biological system, being decoupled or even showing inverse trends with temperature, at Myr scales.

    So warm enough to have a deciduous forest was for completely different reasons. There was very little difference in sea surface temperatures with latitude then, compared with today, because ocean currents flowed NS. You don’t need to be an expert in climate science to know this, so this story highlights how much of a climate tart you need to be to have a successful career in science instead of being good at science.

    These currents make a huge difference even today.

    Quick quiz. Which has the lower coldest temperature on record? Tromso, Norway (300 km inside the Arctic circle) or Tallahassee, Florida?

    • The capital of FL, of course. The North Atlantic Drift is a warm Mama.

      Another factor which GCMs can’t model is Cretaceous equanimity, ie the relative lack of difference between equator and poles. Earth’s tilt range was probably the same then as now, so the evenness of temperature must be down to oceanic and atmospheric circulation, plus just generally a lot warmer.

      CO2 was an effect of this balminess and evenness, not its cause.

  28. They are only a hundred years or so a bit late to “discover” evidence of rainforests . Scott on his race to be first to the pole found and retrieved petrified wood in that trip, before WWI

  29. Quote: “Before our study, the general assumption was that the global carbon dioxide concentration in the Cretaceous was roughly 1000 ppm. But in our model-based experiments, it took concentration levels of 1120 to 1680 ppm to reach the average temperatures back then in the Antarctic.”

    They have a lot of confidence that models that cannot predict next years climate will work on scenarios from 90 million years ago.

  30. Why the surprise of finding Jurassic coal in Antarctica? Not having seen the paper, how this was presented is unclear. However much older coal was found far back in 1907-09. It is easy to find a 36-year-old map on the web showing locations of coal in the Antarctica from the Tertiary, Triassic to as old as the Permian. All coal will show traces of plant material, so nothing new. The Australian CSIRO Division of Coal Research back in the 1960s did analysis and testing of some Antarctica Permian coal samples, in which I participated.

  31. Time waits for no one and no thing. Climate and the Earth are living Systems. Over Billions of year’s on the Earth’s timescale, the Climate and Earth have never been Constant, they will change with all the variables, they will never be static. If the Climate and the Earth ever does become constant, unchanging, flat-lined, that will be when the Earth and Climate are dead. So you have to question any movement who’s Agenda is to STOP Climate Change. Our goal should always be #optimization, #innovation, #reality for #capableenergy, not #subsidies for #incapableenergy. we must question #justintrudeau #left #un #ipcc #climatemodels as to where their plan is really going.

  32. Weather and Climate have many more records than those just witnessed over the past 100years. We have been Warmer, Cooler, Wetter, Drier, Windier throughout time, but NEVER have we been this gullible to think that a regulated, ever-improving society will implode in 10 years! Yes we must do our best, but we must base all Policies on Reality, to the best of our current capabilities, rather than try to fit with Failed Climate Models and Socialist Agendas.

  33. Before we start talking about rainforests at the South Pole, we need to remember that the continents wander over millions of years. Where was Antarctica 90 million years ago? Geologic evidence indicates that 90 million years ago, Antarctica was moving south towards the south pole. Was it at the South Pole at that time, or was it more likely at the current latitude of New Zealand, where there are currently rain forests?

    • The paper claims the site was at 82 degrees S, but it might have been farther north, while still within the Antarctic Circle, far south of NZ.

  34. Please state whatever point you’re trying to make.

    It’s clear from all evidence that climate was much warmer during the Cretaceous. We observe tectonics working today, so that the plates moved in the past is indeed consistent with uniformitarianism.

  35. Always go straight to the abstract. It says the most important information, that the excavated forests were at latitude 82, far enough north to be at a present day Antarctic coast.

    Article, Published: 01 April 2020
    Temperate rainforests near the South Pole during peak Cretaceous warmth
    Johann P. Klages, Ulrich Salzmann, […]

    The mid-Cretaceous period was one of the warmest intervals of the past 140 million years1,2,3,4,5, driven by atmospheric carbon dioxide levels of around 1,000 parts per million by volume6. In the near absence of proximal geological records from south of the Antarctic Circle, it is disputed whether polar ice could exist under such environmental conditions. Here we use a sedimentary sequence recovered from the West Antarctic shelf—the southernmost Cretaceous record reported so far—and show that a temperate lowland rainforest environment existed at a palaeolatitude of about 82° S during the Turonian–Santonian age (92 to 83 million years ago). This record contains an intact 3-metre-long network of in situ fossil roots embedded in a mudstone matrix containing diverse pollen and spores. A climate model simulation shows that the reconstructed temperate climate at this high latitude requires a combination of both atmospheric carbon dioxide concentrations of 1,120–1,680 parts per million by volume and a vegetated land surface without major Antarctic glaciation, highlighting the important cooling effect exerted by ice albedo under high levels of atmospheric carbon dioxide.

  36. That’s interesting. It’s almost as if the ground has shifted thousands of miles. For example, the Grand Canyon has clearly been under the ocean, three times already. That’s a big move, I wonder how long it takes.

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