## Thursday, August 02, 2012 ... /////

### Antarctic palm trees: 52M years ago

Fox News and others just promote a new paper in Nature

Persistent near-tropical warmth on the Antarctic continent during the early Eocene epoch (by Jörg Pross + 16 co-authors)
which claims the discovery of traces of palm trees that apparently lived in the Antarctica 52 million years ago.

A photograph of the Antarctic beaches that Al Gore and Jasoň Mráz could have taken 52 million years ago.

The trees were apparently close relatives of the tropical Baobab trees (pictured above) that may be found in Madagascar these days.

The most convincing smoking guns supporting their claims are fossil pollen and spores apparently coming from the Antarctic coasts.

The authors think about various parameters and decide that even winters in the Antarctica had to be very mild – warmer than +10 °C – and frost-free. This apparent fact provides us with a "new constraint for the validation of the climate models", the 17 authors (thanks, Willie) claim at the end of the abstract. In other words, the finding, if true, proves that all existing climate models are complete rubbish because they obviously don't allow the continental temperatures to naturally change by this much.

How much?

If you visit the Antarctica these days, in the winter (don't forget it's the Southern Hemisphere – I don't want to use the term "other hemisphere" because I respect the Aussie, Kiwi, South African, and Latin American TRF readers), the lowest temperatures in the bulk of the cold continent reach something between –80 °C and -90 °C. The lowest ever recorded temperature was over there, of course, and it was –89.2 °C. Yes, it is at least 100 °C cooler than the temperatures you find most comfortable.

Comments about the role of CO2 are totally preposterous because the concentration at that time wasn't really too much above 500 ppm, the long-term average for the epoch (the Paleogene) which is just 20 percent above the current one. Even with the most insanely high estimates of the climate sensitivity, you could argue that the temperature could have been one doubling i.e. 3-5 °C higher than today. You still need to explain 95 °C or 100 °C of warming.

Needless to say, the presence of the palm trees has entirely different reasons. One of them – completely neglected by the writers – is the continental drift. 50 million years isn't too much but it isn't quite negligible, either. The picture above shows you the likely positions and shapes of the continents 70 million years ago. You see that there's some potential for the Antarctic coasts to be much closer to the current location of Madagascar than they are today.

The hypothesis that the warm Antarctica was man-made requires us to believe that Tubab [=White] Women were living and driving cars next to the Baobab [=Fruit Of Many Seeds] trees.

However, what's much more important – and Richard Lindzen often emphasizes this degree of freedom – is that various circulations were different and led to a much lower polar-equatorial temperature difference i.e. much smaller gradients. At that time, the poles were just not as different from the equator as they are today. Such "regional" changes of the Earth's climate are obviously much more important than a few degrees of "global warming" because they're able to change the regional climate by something that is closer to 100 Celsius degrees than to one degree.

At any rate, there are many questions that deserve an ever more reliable and accurate answer but if the suggestions by the paper in Nature are right, there are several lessons we may learn, including
1. Nature is able to make continents up to 100 °C warmer than today even if the CO2 concentration is almost identical to the current concentration
2. The increase of a continental temperature by 100 °C doesn't necessarily mean a problem – in fact, it may be extremely beneficial for life.
You may say that it is an extremely long time ago when the palm trees lived there but it is not a long time from a geological viewpoint: the Earth was just 1% younger than it is today. Mammals were already around and some of them began to evolve into primates, a category that humans proudly share with apes and monkeys.

People shouldn't forget about this research next time when the fearmongers try to convince them that they should be afraid of every Celsius degree of temperature change.

And that's the memo.

This blog entry is on a light topic, namely biology and climatology, so another song by the Yellow Sisters 2012: the ants are moving behind the next tree. ;-) The Yellow Sisters also know how to rap, see e.g. the video clip on Lactation Psychosis by young director Ms Tereza Nvotová (who made a documentary on me, too).

#### snail feedback (33) :

I believe the Wilkes land coast of east antarctica has winter temperatures from -20 to -30°C as recorded by australian Casey station or french Dumont d'Urville station. The -80+°C have been measured on a plateau at 4000m altitude.

NASA GISS says that CO2 has absolute domain over global temperature. They 'prove' this by running their climate model with zero CO2 and measure an iceball Earth. This 'observational data' is dead-certain.

NASA GISS relies on paleo data to provide the equilibrium climate sensitivity.

This paper clearly shows that a CO2 doubling results in a 100 C GLOBAL temperature rise. This follows the widely accepted practice of using a few ice cores from Antarctic as proxies for global temperatures going back 1 million years.

I can only conclude from this *flawless* logic that CO2 climate sensitivity is much worse than we thought.
/sarc

I beg your pardon but in southern hemipshere every thing is is the opposite so the temperature in antatcia is - - 80°C so +80°c.

Don't want to be a fearmonger, but a 50 degree rise in the wrong place would make the oceans boil off.

I couldn't read the paper itself, but I doubt they would have used the word "palaeolatitude" unless they were taking continental drift into account.

http://en.wiktionary.org/wiki/palaeolatitude

Jolly Joker-I can't comment on whether they have taken continental drift into account in explaining the cause of the Antarctic warmth. But I can comment on this:

"a 50 degree rise in the wrong place would make the oceans boil off."

I can assure you there is no danger of such a thing occurring, at least not until the sun becomes sufficiently bright, which is inevitable. The reason is that, while very large temperature changes are characteristic of polar regions, they simply haven't been documented for the tropical regions-the only places where such a large temperature change would come close to the boiling point of water. The Eocene is one of the most dramatic examples of how the poles may change dramatically while the tropics change very little. And this has proven to be a very difficult thing for climate models to replicate, particularly because early work suggested that the Eocene was actually cooler in the tropics! This was of course "corrected" so we now think they were a little bit warmer. Models can now get the tropics right, or the poles right, but not both, so there are attempts to warm up the past tropics more, since this would imply the models have too low a sensitivity!!! Also, you can't really cool down the Eocene poles because you can't erase the Alligator fossils in Spitsbergen. So they try to say there were giant Snakes that couldn't survive without ridiculously hot temperatures in the tropics-not kidding! ;)

The fact that temperature variations are pretty much always bigger at the poles than near the equator, appears to have been discovered by Russian climatologists Mikhail Budyko and Yuri Izrael.

lol, I'm not suggesting global warming would actually raise the temps by 50 degrees :) I was referring to Lubos' claim that a 100 degree rise isn't necessarily a problem (well, yes, necessarily).

Obviously you can get large changes over 100Myear scales for a given continent by shuffling them around, but the max temp of a sea region (large enough to cause runaway warming if it boiled) wouldn't change much then.

of CO2 are totally preposterous because the concentration at that time wasn't
really too much above 500 ppm, the long-term average for the epoch (the
Paleogene) which is just 20 percent above the current one.

This is not true. At the Eocene thermal maximum CO2 concentrations were above 1000 ppm (as the paper clearly states). Today we are 390 ppm. The ratio is (at least) 2.6 times today CO2 concentration. The increase is 1600% above the current one.

Even with the most
insanely high estimates of the climate sensitivity, you could argue that the
temperature could have been one doubling i.e. 3-5 °C higher than today.

With 3ºC of climate sensitivity (the most likely value according to historical instrumental and paleoclimate data) a *2.6 times bigger concentration of CO2 imply 7-8 ºC warmer global temperatures than today.

You
still need to explain 95 °C or 100 °C of warming

I cannot believe that a string theory physicist cannot tell the difference between global and regional warming.

That insane warming in paleolatitudes similar to the ones of most of today Antartica coast (70º south,as is indicated in the abstract) was a regional one, and shows something called polar amplification, the fact that high latitudes warm much more during warming episodes than the rest of the world (and cool much more during cooling episodes).

High CO2 levels were not the only factor that warmed the earth in the Eocene, a different ocean circulation due to the continents different position then also contributed. But certainly, this finding is consistent with a high climate sensitivity and would be very difficult to explain without the enhanced greenhouse effect.

[Excuse me for posting the comment twice. I wrote the quotes of the TRF post in italics (at least I tried to do it) but the italics didn't show up. I will put your quotations between "" instead in the second (mirror) comment]

"Comments about the role of CO2 are totally preposterous because the concentration at that time wasn't really too much above 500 ppm, the long-term average for the epoch (the Paleogene) which is just 20 percent above the current one."

This is not true. At the Eocene thermal maximum CO2 concentrations were above 1000 ppm (as the paper clearly states). Today we are 390 ppm. The ratio is (at least) 2.6 times today CO2 concentration. The increase is 1600% above the current one.

"Even with the most insanely high estimates of the climate sensitivity, you could argue that the temperature could have been one doubling i.e. 3-5 °C higher than today."

With 3ºC of climate sensitivity (the most likely value according to historical instrumental and paleoclimate data) a *2.6 times bigger concentration of CO2 imply 7-8 ºC warmer global temperatures than today.

"You still need to explain 95 °C or 100 °C of warming"

I cannot believe that a string theory physicist cannot tell the difference between global and regional warming.

That insane warming in paleolatitudes similar to the ones of most of today Antartica coast (70º south,as is indicated in the abstract) was a regional one, and shows something called polar amplification, the fact that high latitudes warm much more during warming episodes than the rest of the world (and cool much more during cooling episodes).

High CO2 levels were not the only factor that warmed the earth in the Eocene, a different ocean circulation due to the continents different position then also contributed. But certainly, this finding is consistent with a high climate sensitivity and would be very difficult to explain without the enhanced greenhouse effect.

Jolly Joker-Oh but it will-natural, sun caused global warming will boil the oceans in billions of years. We have a lot of time, but we must eventually develop space travel and find a habitable alternative planet, or some other massive project of future human society. Well, maybe an asteroid impact or something else that would cause extinctions will kill us before we get the chance-if humanity lasts billions of years we will have surpassed all life forms in longevity, I think, although we will have evolved to be unrecognizable so perhaps it won't count.

Note, Wikipedia seems excessively alarmist to me, suggesting that a 10% luminosity increase in only 1.1 billion years will be sufficient to evaporate the oceans away. IMAO, this is probably way too pessimistic-assuming no feedback it would lead to a temperature change of about six degrees-naturally wiki claims that the actual warming will be more than five times greater! On the basis of the change in climate they expect from a brighter sun, they also suggest a large change in the weathering rate of silicate minerals, which will draw down atmospheric CO2 in 600 million years so low that C3 carbon fixation will fail (below 50 ppm). They say that many plants would die at that point, and even more when C4 fixation fails, but I think present day plants would die much sooner, since just because you can perform the photosynthetic reaction doesn't mean it's high enough for the plants to be healthy (many modern plants do very badly even with concentrations near those at the end of the last ice age). But once the reaction is no longer possible, no amount of evolution will allow any form of plants to continue. Apparently animals might survive a little longer by a few million years-I find that a little implausible, but whatever. But severe changes to the Earth and it's climate will assuredly occur within a few billion years.

Fine, I realize and I did mention the difference between coasts and the bulk. Still, the then-vs-today difference of the temperature was around 50 deg C at the same place.

Nice joke. And minus 6 feet tall people are earning minus 40,000 dollars a year, distributing money as they work, right?

Hi nutcase, the increase by the factor of 2.6 isn't increase by 1,600% but just 160%. Check your kindergarten maths, "scientist". This doesn't change anything at all. I said that the CO2 concentration was around 1 doubling above the current one but if it were ln(2.6)/ln(2) = 1.38 doublings around the current one, even the most insane (high) estimates of the sensitivity would only imply climate which is warmer by 6 degrees or so, leaving the remaining 50-100 degrees unexplained.

"I cannot believe that a string theory physicist cannot tell the difference between global and regional warming."

On the contrary, the difference between those two is the very main point of my article. Warming that matters is always regional; global warming never matters in practice. It's the alarmist crackpots who are denying these basic facts and who, by using deliberately misleading phrases such as "global warming", suggest that the temperatures are changing uniformly over the globe. This ain't the case.

"But certainly, this finding is consistent with a high climate sensitivity and would be very difficult to explain without the enhanced greenhouse effect."

As the numbers that the very idiot called you has repeated, the greenhouse effect has absolutely nothing to do with more than 5% of this observation.

Dear JollyJoker, as Werdna says, no change of this kind could make the oceans boil. The evaporation latent heat of water is equivalent to more than 500 Celsius degrees of warming (500 Celsius degrees times specific heat capacity of water). So if you reach the boiling point, you have to insert the same heat as if you were heating the water by 500+ degrees, and only afterwards, the temperatures could continue to rise. Equivalently, by reaching the boiling point for a tiny piece of the water, the warming stops and the rest (majority) of the water remains liquid.

And as I have emphasized, it was really a main point of this blog entry, the temperatures at various places of the globe are simply not changing in unison. The fact that the Antarctica was 50-100 Celsius degrees warmer than today does *not* imply that the equator was 50-100 Celsius degrees warmer than today. Quite on the contrary, it could have been *cooler* than today!

When thinking on whether or not the Sun in the previous 4.7 billion years (or future few billion years) had a chance to evaporate chunks of oceans, it is not useful to use the global mean temperature at all. You may just approach this problem as follows: pick the hottest place on Earth at a hypothetical past or future moment and look at its temperature. Now, everything else is cooler so all the other flows and circulations are trying to cool that place. You have the chance to sustain very high temperatures if you maximally suppress all circulation. The positive contribution is given by the Sun but if you calculate the numbers, it's very clear that the solar irradiance simply doesn't have enough energy to evaporate pieces of ocean even at "optimal" geometries.

My apologies to TRF readers that I make a mistake putting am extra "0" in the 1600%. In any case, your result is also wrong,

Could you please be more specific on what you consider "wrong" about my result? My result is that CO2 greenhouse effect can't explain more than 10% of the temperature difference. The precise numbers are unknown but the qualitative result is indisputable: CO2 is irrelevant for all such climate-related questions.

[I pressed the "post" button by accident. please delete that comment]

My apologies to TRF readers for making the mistake of adding an extra "0" and I admit it. However, your numbers are also wrong. You said 20% more CO2 than today: that's wrong by a factor of 8. The concentration of CO2 in the Eocene was not 500ppm , it was above 1000 ppm, as the paper clearly indicates.

Your numbers were wrong likely because you consider the period in question as the paleogene average. Here there is more time precision: the paper clearly states that "we present a well-dated record of early Eocene climate on Antarctica". During this specific geologic epoch, CO2 was above 1000ppm.

Now climate sensitivity λ. It can be computed with the formula:

λ = dT/dF = dT/(5.35 * ln[2])

Studies have given a possible range of values of 2-4.5°C warming for a doubling
of CO2. So:

λ= [2 to 4.5°C]/3.7 = 0.54 to 1.2°C/(W/m2)

From the formula:

dT=λ(5.35 * ln[1000ppm/390ppm])

The warming due to 1000 ppm is about 3-6ºC above today temperatures. (yes my first estimate of 7-8ºC was wrong. But saying that warming would be just 1-1.5ºC is even worse. However I, unlike you, do not stick to wrong numbers. If something I say is wrong, I correct it.)

You then are saying that the global average do not matter and that " deliberately misleading phrases such as "global warming", suggest that the temperatures are changing uniformly over the globe."

No climate scientist has never said such a mostruosity. You assume that them did and then you apply an (underestimated) global average as the uniform warming of the globe.

This is a straw man argument. Climate scientists have predicted for decades polar amplification. It is observed today and in the paleoclimate record.

Finally, I have a question for you:

If CO2 do not control earth temperature, caused and then ended the snowball earth events 600 million years ago?

To the TRF audience: Snowball earth events are the biggest variations ever in earth climate, when in a few million years the planet freeze down to the equator and then, after some million of years of CO2 accumulation (due to suppressed weathering) after reaching approximately 100 000 ppm, all the ice in the planet melted. The variations are actually nearly 100ºC GLOBAL temperature changes .

http://en.wikipedia.org/wiki/Snowball_Earth

Not necessarily. There are loads of ways we can compensate for a more luminous sun, since it happens so incredibly slowly. Solar shades in orbit are a simple way of cooling the planet but my favorite by far is moving the Earth slowly outwards by using an asteroid to loop around the Earth and Jupiter, adding speed to the Earth and slowing Jupiter down :)

Okay, yes, this is covered under "some other massive project of future human society."

Still, the Earth has to get very far out, to last several billion years. By 7.5 billion years, the Red Giant Sun will have swallowed the Earth's current orbit, plus a little more, and the habitable zone may include Titan!

And of course, as we get late in the Sun's life, more things happen: helium flash, accompanied by the sun decreasing in size and brightness again-if we have taken the Earth out far enough, this will probably freeze the Earth over. After that (which is several billion years out), in another merely a 100 million years, the sun will become an asymptotic giant branch star, brighten again which may allow the Earth to warm up again. That phase will last 30 million years, and then over a course of 100 thousand years, the outer layers of the sun will be expelled to form a planetary nebula-this will wreak havoc with the planets' orbits, although it won't incinerate them like a Supernova, it may lead to collisions, ejections from the system, some even being torn apart by tidal interactions. If we can survive even that we will be left orbiting far out from a white dwarf star. This will dim over time, so even if we move the Earth in close again, in trillions of years it will be a black dwarf and there will just be no sunlight to keep the Earth warm. So we can perhaps extend our stay on Earth by a few billion extra years, but I doubt we will be living on Earth more than say, seven billion years from now.

If ocean currents played a major role in the ancient warm Antarctica (and not so much continental drift) wouldn't that mean the palm trees had to endure a few months of very little light in the winter? What an interesting place it must have looked like in winter, palm trees in long, twilight-y nights, wonder what other sorts of plants were growing there.

Because of the efficiency of heat transport, the main driver of weather, an increase of 18 degrees for the mean annual temperature of the Earth results in an increase of up to five times that or 90 degrees at the poles. All we need to explain is 18 degrees.

So back when Australia, Antarctica, South America and Africa were one landmass, located outside of the Antarctic circle, and polar oceans were just extended bodies of the water on the outskirt of the Pacific Ocean, there was no land for polar ice-caps to moor to. The ice was just flushed out in the ocean circulation.Makes sense to me.

Lubos Motl... can you concur with this? I am a skeptic of AGW and find that other skeptics do not seem to realize this when it is important to do so. Warmists will claim that the larger warming at the poles is due to amplification from albedo without understanding that most of this difference (between poles and equator) is due to heat transport (weather).

Dear Laurence, I agree these are important issues not to be overlooked.

Well, there are many factors here. First, there is a zeroth-order-approximation reason why poles are colder then the equator in average, of course: less sunshine because of the altitudes of the Sun right above the horizon.

Another issue is that the temperature variations at the poles tend to be larger, both weather oscillations and long-term climate oscillations. This has many reasons, including

1) ice-albedo feedbacks etc.
2) dependence of the polar regions on the inflow of heat from the warmer regions, i.e. sensitivity to changes of circulation

I think that for any mean annual temperature of the Earth any change would quickly be restored to the fixed ratio for that temperature due to the efficiency of heat transport. That is, the temperature ratio between poles and equator for the atmosphere would be restored within a year.

OK, I don't believe this claim is right. After all, if this very Antarctic study is true, it contradicts your assertion. I think that there can be lots of circulation modes that imply totally different distributions of the temperatures over the globe.

How can this study contradict that when 5 x 18= 90? When the axial rotation of the Earth determines the prevailing winds how can any factor override that? The colder the mean annual temperature the stronger the north to south and south to north flow and the warmer the weaker that flow.

You did not explain how it contradicts. I would expect a physicist to readily acknowledge that the underlying fundamental is that heat transport determines the gradient as the meteorologists inform us.

I guess that temperatures and C02 on a large scale in geological history were not related, so we can clearly conclude that CO2 has little impact.
http://realagenda.files.wordpress.com/2011/01/figure-7.jpg?w=490

To exactly understand the conditions on earth 50 Million years ago is difficult, since the continents were distributed differently then today, so also ocean currents were different.

According to the study, "the Equator-to-pole temperature gradients were much smaller than today". This shows that the warming was much greater at the poles than at the equator.

Apologies, warming from which moment through which moment? Are you sure you are not confusing a high temperature with a high rate of warming, a function with its time derivative?

Are you sure you cannot give any reason why the temperature gradient would vary for any particular mean annual temperature? So far you have been unable to do so. If the source of the warming is in the polar regions, such as increased albedo, this would still be distributed globally according to the same temperature gradient. It is surprising that a physicist, of all people, would not be able to credit this at all. The timing does not matter. We are talking about from one mean annual temperature to another. With a higher mean annual temperature there will be necessarily a lower temperature gradient and vice versa.As the article states, it was warmer then and it had a lesser temperature gradient. That is why you do not need 90 degrees warming of the mean annual temperature to get 90 degrees warming at the poles. The rate of warming is irrelevant as long as we are talking about climate and not weather. Weather is driven by heat transport and that quickly maintains the gradient.

Dear Laurence, of course that I can give you reasons why the temperature gradients are changing.

First, however, let me emphasize that the pole-equator temperature difference, the main difference that dictates the dependence on the latitude and the gradients, is totally independent from the global mean temperature. They have nothing to do with each other. In terms of spherical harmonics, the global mean temperature goes like Y_{00} while the polar-equatorial difference is dominated by Y_{20}, a totally different and orthogonal spherical harmonic.

The changes of the latter are much more important in determining the climate pretty much anywhere on the globe. Those things are really deciding whether or not you ultimately have a snowball Earth or not.

See e.g. the Lindzen-Hou 1988 paper on Hadley circulation to see how the equator-to-pole temperature difference is evolving and why:

http://eaps.mit.edu/faculty/lindzen/hrcrzahteq.pdf

The paper has 200+ cits now. See 250+ papers that contain the exact phrase "equator to pole temperature difference":