Hans Erren - Elisa Ideat · Arrhenius' greenhouse effect with a prism of salt A historical review Hans Erren 12 September 2006 Global Warming - Scientific Controversies in Climate

Arrhenius' greenhouse effect with a prism of saltArrhenius' greenhouse effect with a prism of salt

A historical review A historical review

Hans ErrenHans Erren

12 September 200612 September 2006

Global Warming - Scientific Controversies in Climate Variability Global Warming - Scientific Controversies in Climate Variability International seminar meeting at KTH, Stockholm, Sweden, September 11-12th 2006International seminar meeting at KTH, Stockholm, Sweden, September 11-12th 2006

IntroductionIntroduction

John Tyndall, 1872, John Tyndall, 1872, Contributions to Molecular Physics in the Domain of Radiant Heat. A Series of Memoirs published in the Contributions to Molecular Physics in the Domain of Radiant Heat. A Series of Memoirs published in the 'Philosophical Transactions' and 'Philosophical Magazine,' with Additions. 'Philosophical Transactions' and 'Philosophical Magazine,' with Additions. London: Longmans Green and Co, p1-65London: Longmans Green and Co, p1-65

Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. iv. 9th mem. 193pp iv. 9th mem. 193pp

Svante Arrhenius, 1896a, Ueber den Einfluss des Atmosphärischen Kohlensäurengehalts auf die Temperatur der Svante Arrhenius, 1896a, Ueber den Einfluss des Atmosphärischen Kohlensäurengehalts auf die Temperatur der Erdoberfläche, Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar, Stockholm 1896, Band 22 Afd I N:o Erdoberfläche, Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar, Stockholm 1896, Band 22 Afd I N:o 1, p1-101.1, p1-101.

Svante Arrhenius, 1896b, On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, The London, Svante Arrhenius, 1896b, On the Influence of Carbonic Acid in the Air upon the Temperature of the Ground, The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science [fifth series] April 1896. vol 41, p237-275Edinburgh, and Dublin Philosophical Magazine and Journal of Science [fifth series] April 1896. vol 41, p237-275

Langley & Abbot, 1900, Annals of the Astrophysical Observatory of the Smithsonian Institution, Volume ILangley & Abbot, 1900, Annals of the Astrophysical Observatory of the Smithsonian Institution, Volume I

Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Annalen der Physik Bd 3. 1900, p720-732.Annalen der Physik Bd 3. 1900, p720-732.

Svante Arrhenius, 1901a, Ueber die Wärmeabsorption durch Kohlensäure, Annalen der Physik Bd 4. 1901, p690-705.Svante Arrhenius, 1901a, Ueber die Wärmeabsorption durch Kohlensäure, Annalen der Physik Bd 4. 1901, p690-705.

Svante Arrhenius 1901b Über Die Wärmeabsorption Durch Kohlensäure Und Ihren Einfluss Auf Die Temperatur Der Svante Arrhenius 1901b Über Die Wärmeabsorption Durch Kohlensäure Und Ihren Einfluss Auf Die Temperatur Der Erdoberfläche. Öfversigt af Kongliga Vetenskaps-Akademiens Förhandlingar 58: 25-58.Erdoberfläche. Öfversigt af Kongliga Vetenskaps-Akademiens Förhandlingar 58: 25-58.

QuotesQuotes

● Arrhenius' 1896 data go up to 30 micron ● Arrhenius' 1896 data stop at 3 micron ● The CO2 spectrum is saturated● Revised calculations, finding a somewhat lower effect, were

given in Arrhenius (1901)

Ramanathan & Vogelmann 1997 AMBIO, 26(1):38-46 Baliunas & Soon 1999 http://www.greeningearthsociety.org/climate/previous_issues/vol4/v4n19/cutting1.htmCourtney 2000 http://www.john-daly.com/solar/keldebat.htmWeart 2003 http://www.aip.org/history/climate/co2.htm

http://www.greeningearthsociety.org/climate/previous_issues/vol4/v4n19/cutting1.htm

http://www.john-daly.com/solar/keldebat.htm

http://www.aip.org/history/climate/co2.htm

12 September 2006 Hans Erren 4

Prologue: Allegheny Observatory, Prologue: Allegheny Observatory, Pittsburgh USA,Pittsburgh USA, 1887 1887

Samuel Pierpont LangleyJohn BrashearFrank Very

Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. iv. 9th Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. iv. 9th mem. 193pp mem. 193pp



δ


““Arrhenius' 1896 data go up to 30 micron”Arrhenius' 1896 data go up to 30 micron”


Act I: Stockholms HögskolaAct I: Stockholms Högskola 18951895

Where T= temperatureK = a constant ν =co-albedo 1-β = atmospheric IR transmission Svante Arrhenius



Table IITable II


TableTable IIIIII


Act II: TenerifeAct II: Tenerife 19001900

Knut Ångström

Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Annalen der Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Annalen der Physik Bd 3. 1900, p720-732.Physik Bd 3. 1900, p720-732.


“The absorption of CO2 is 18%”Knut Ångström (1900)


“The spectrum of CO2 is saturated”Knut Ångström (1900)

“The observations stop at 3 micron”Soon & Baliunas


The CO2 Spectrum is not saturatedThe CO2 Spectrum is not saturated


Smithsonian, Cambridge MA, Smithsonian, Cambridge MA, 19001900

Charles AbbottSamuel Langley



Updated NaCl propertiesUpdated NaCl properties


Arrhenius Table IIArrhenius Table II


End of Story ?End of Story ?

The Allegheny spectra are primarily water spectra and cannot be used for CO2 estimatesCO2 absorption is 18%“CO2 is saturated”


Act III, Charlottenburg, BerlinAct III, Charlottenburg, Berlin19011901

Heinrich RubensSvante Arrhenius



Rubens' experimental setupRubens' experimental setup


Flashback: Royal Institution, London Flashback: Royal Institution, London 1859-18721859-1872

John Tyndall



Tyndall experiment setupTyndall experiment setupTyndall experiment setupTyndall experiment setup


Arrhenius vs Tyndall Arrhenius vs Tyndall

Arrhenius 1901 Tyndall 1872


Arrhenius “adjusts” TyndallArrhenius “adjusts” Tyndall


NaCl effectNaCl effect




Arrhenius vs. ModtranArrhenius vs. Modtran

QuotesQuotes● Arrhenius' 1896 data go up to 30 micron● Due to strong absorption it is very difficult to measure Due to strong absorption it is very difficult to measure

infrared radiation using rock salt prisms beyond 20 micron. infrared radiation using rock salt prisms beyond 20 micron. Arrhenius' 1896 data goes up to 12 micron, and contains Arrhenius' 1896 data goes up to 12 micron, and contains mainly water vapour, this data is useless to calculate the mainly water vapour, this data is useless to calculate the absorption of CO2. absorption of CO2.

● Arrhenius' 1896 data stop at 3 micron ● AngstromAngstrom's data stop at 3 micron's data stop at 3 micron● The CO2 spectrum is saturated● The CO2 spectrum is not saturated, this argument originates The CO2 spectrum is not saturated, this argument originates

from Knut Angstrom who measured a solar spectrum where from Knut Angstrom who measured a solar spectrum where CO2 has only marginal absorption.CO2 has only marginal absorption.

Ramanathan & Vogelmann 1997 AMBIO, 26(1):38-46 Baliunas & Soon 1999 http://www.greeningearthsociety.org/climate/previous_issues/vol4/v4n19/cutting1.htmCourtney 2000 http://www.john-daly.com/solar/keldebat.htm

http://www.greeningearthsociety.org/climate/previous_issues/vol4/v4n19/cutting1.htm

http://www.john-daly.com/solar/keldebat.htm

QuotesQuotes● Revised calculations, finding a somewhat lower effect, were

given in Arrhenius (1901) ● The 1901 calculated trend is dominated by two effects: The 1901 calculated trend is dominated by two effects: 1) A high absorption at low temperature due to infrared cutoff 1) A high absorption at low temperature due to infrared cutoff

by rock salt.by rock salt.2) Unreported reduction of the original observations by 2) Unreported reduction of the original observations by

Tyndall.Tyndall.

Arrhenius tuned the data in such a way that the new Arrhenius tuned the data in such a way that the new calculations confirmed his earlier work. Using modern data calculations confirmed his earlier work. Using modern data leads to a substantially lower CO2 absorption trend, and leads to a substantially lower CO2 absorption trend, and hence a far lower climate sensitivity. hence a far lower climate sensitivity.

Weart 2003 http://www.aip.org/history/climate/co2.htm

http://www.aip.org/history/climate/co2.htm


ConclusionsConclusions● Arrhenius:Arrhenius: The 1896 publication uses data without CO2, The 1896 publication uses data without CO2,

but mainly shows water absorption, due to the wrongly but mainly shows water absorption, due to the wrongly extrapolated refractive index of rock salt. The observations extrapolated refractive index of rock salt. The observations stop at 12 micron.stop at 12 micron.

● The high CO2 absorption trend calculated by Arrhenius in The high CO2 absorption trend calculated by Arrhenius in 1901 is influenced by the infrared cutoff of rock salt. 1901 is influenced by the infrared cutoff of rock salt.

● Arrhenius reduced Tyndall's data with a factor 3.6 to match Arrhenius reduced Tyndall's data with a factor 3.6 to match his own observationshis own observations without reporting this. without reporting this.

● Angstrom:Angstrom: The CO2 spectrum is not saturated, CO2 The CO2 spectrum is not saturated, CO2 absorption in the solar spectrum was below instrumental absorption in the solar spectrum was below instrumental detection.detection.


TRUST BUT VERIFYTRUST BUT VERIFY


AcknowledgementsAcknowledgements● The librarians of the Utrecht and Delft universities● Solar spectra using SMARTS freeware from the Renewable

Resource Data Center ● Hitran online database at the Institute of Atmospheric

Optics, Tomsk, Russia● Modtran3 online (David Archer)● The conveners of this conference

This presentation was created using Open Office


Arrhenius' greenhouse effect with a prism of saltArrhenius' greenhouse effect with a prism of salt

A historical review A historical review

Hans ErrenHans Erren

12 September 200612 September 2006

Global Warming - Scientific Controversies in Climate Variability Global Warming - Scientific Controversies in Climate Variability International seminar meeting at KTH, Stockholm, Sweden, September 11-12th 2006International seminar meeting at KTH, Stockholm, Sweden, September 11-12th 2006

In 2003 I published a historical review on the Internet of the Arrhenius 1896 publication. I am flattered that Peter Stilbs invited me to this conference to give a presentation about my findings. I hadn't looked in detail at the 1901 publications of Arrhenius and to my own surprise these revealed even more interesting findings which I will show you in the second part of my presentation.


IntroductionIntroduction


Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. iv. 9th mem. 193pp iv. 9th mem. 193pp

Svante Arrhenius, 1896a, Ueber den Einfluss des Atmosphärischen Kohlensäurengehalts auf die Temperatur der Svante Arrhenius, 1896a, Ueber den Einfluss des Atmosphärischen Kohlensäurengehalts auf die Temperatur der Erdoberfläche, Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar, Stockholm 1896, Band 22 Afd I N:o Erdoberfläche, Bihang till Kongliga Svenska Vetenskaps-Akademiens Handlingar, Stockholm 1896, Band 22 Afd I N:o 1, p1-101.1, p1-101.



Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Annalen der Physik Bd 3. 1900, p720-732.Annalen der Physik Bd 3. 1900, p720-732.

Svante Arrhenius, 1901a, Ueber die Wärmeabsorption durch Kohlensäure, Annalen der Physik Bd 4. 1901, p690-705.Svante Arrhenius, 1901a, Ueber die Wärmeabsorption durch Kohlensäure, Annalen der Physik Bd 4. 1901, p690-705.


This presentation will discuss the works of Arrhenius of 1896, of which the English publication (in red) is the most well known, I will also discuss his works of 1901 which only were published in German. Related and quoted works by Langley, Angstrom and Tyndall will also be touched upon.

The climate work of Arrhenius consists of only two original publications published by the Swedish academy, the other two are summaries of the first ones.


QuotesQuotes

● Arrhenius' 1896 data go up to 30 micron ● Arrhenius' 1896 data stop at 3 micron ● The CO2 spectrum is saturated● Revised calculations, finding a somewhat lower effect, were

given in Arrhenius (1901)

Ramanathan & Vogelmann 1997 AMBIO, 26(1):38-46 Baliunas & Soon 1999 http://www.greeningearthsociety.org/climate/previous_issues/vol4/v4n19/cutting1.htmCourtney 2000 http://www.john-daly.com/solar/keldebat.htmWeart 2003 http://www.aip.org/history/climate/co2.htm

This presentation will also show the the origin of some quotes about the work of Arrhenius.


Prologue: Allegheny Observatory, Prologue: Allegheny Observatory, Pittsburgh USA,Pittsburgh USA, 1887 1887

Samuel Pierpont LangleyJohn BrashearFrank Very

Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. iv. 9th Samuel P. Langley (and Frank W. Very),1890, The Temperature of the Moon, Memoir of the National Academy of Sciences, vol. iv. 9th mem. 193pp mem. 193pp

In his 1896 publication Arrhenius relies strongly on the observations don on the Allegheny observatory in Pittsburgh. Most of the work was done by Frank Very of for who I could not find a picture. The other two gentlemen on the slide are Samuel Langley on the left (who invented the bolometer) and John Brashear on the right who was a very good craftsman. He made the instruments at the observatory.


This is the instrumental setup of the infrared observations at the Allegheny observatory. The lunar light enters from the left, falls on a mirror and is dispersed using a prism of rock salt, as glass is opaque for infrared light. The rock salt is dimmed by condensed water and Brashear had much work with polishing the prism to perfect optical condition.The infrared spectrum is measured using a bolometer and a sensitive galvanometer.


δ

One of the unknowns in the days of Langley was the exact relationship between wavelength and deviation in the infrared. This album sleeve of Pink Floyd (From the album “Dark side of the moon”) shows the relationship that is needed.


““Arrhenius' 1896 data go up to 30 micron”Arrhenius' 1896 data go up to 30 micron”

Cauchy had proposed a simple law for the refractive index, but this law has a singularity in the infrared. Langley made some observations (in green) and presented an linear extrapolation of these data (in pink).

The second graph shows a summary of the lunar observations, which shows that the observations go down to 35 degrees prism deviation, corresponding with an extrapolated wavelength of 30 micron.

So here we have the source of the claim that Arrhenius data go up to 30 micron.


Act I: Stockholms HögskolaAct I: Stockholms Högskola 18951895

Where T= temperatureK = a constant ν =co-albedo 1-β = atmospheric IR transmission Svante Arrhenius


Enter Svante Arrhenius, who was looking for an explanation of the ice ages and thought to have found it in the change of carbon dioxide (Carbonic Acid). He modified the just published law of Stefan, in which the absorption of the atmosphere plays the fundamental role.


Table IITable II ● Click to add an outline

Here is table II of his 1896 publication. The spectral data of Langley and Very are shown on the third column, and using a least squares method he derives the spectra of Co2 and water vapour.

Which is also shown in s graph.


TableTable IIIIII

In table III the absorption of CO2 and water vapour is summarised for increasing and decreasing values. As can be seen the atmosphere is opaque at values of 40 x CO2.

The graph shows a logarithmic x-axis where 1x Co2 is 250 atm.cm


Act II: TenerifeAct II: Tenerife 19001900

Knut Ångström

Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Annalen der Ångström K, 1900, Ueber die Bedeutung des Wasserdampfes und der Kohlensäure bei der Absorption der Erdatmosphäre. Annalen der Physik Bd 3. 1900, p720-732.Physik Bd 3. 1900, p720-732.

Knut Angstrom (the son of) did some observations by himself on the top of mount Teide on the Island of Tenerife. He constructed a double tube of which one was filled with CO2 and measured the difference in absorption in solar rays.He did not measure any difference.

In the same paper he also presented a very modern CO2 absorption spectrum.


“The absorption of CO2 is 18%”Knut Ångström (1900)

Here is the comparison of the graph of CO2 by Angstrom and a modern dataset using Hitran data.

Note that Angstrom used a predecessor of the Planck blackbody law.


“The spectrum of CO2 is saturated”Knut Ångström (1900)

“The observations stop at 3 micron”Soon & Baliunas

Here is the explanation why Knut Angstrom could not detect a CO2 effect in the solar spectrum: There hardly is any CO2 absorption in the solar spectrum. Angstrom wrongly concluded that the CO2 spectrum is saturated and this theory is still hunting the climate Internet fora.

Baliunas and Soon based their conclusion that Arrhenius observations go only up to 3 micron on solar spectra, which of course were not used by Arrhenius to do his calculations.


The CO2 Spectrum is not saturatedThe CO2 Spectrum is not saturated

This straightforward application of the Lambert-Beer absorption law shows how the absorption of CO2 increases through the sidelobes.


Smithsonian, Cambridge MA, Smithsonian, Cambridge MA, 19001900

Charles AbbottSamuel Langley


Charles Abbott Joined Samule Langley, Frank Very left, and John Brashear kept making splendid instruments.


Updated NaCl propertiesUpdated NaCl properties

In the mean time the NaCl properties were updated and the linear extrapolation by Langley was proven erroneous. The 35 degree prism deviation correspond with a wavelength of only 12 micron.


Arrhenius Table IIArrhenius Table II

The implications for Arrhenius table II are disastrous. The least squares spectra of CO2 and water vapour are fantasy and the Allegheny data only shows water vapour.


End of Story ?End of Story ?

The Allegheny spectra are primarily water spectra and cannot be used for CO2 estimatesCO2 absorption is 18%“CO2 is saturated”

No, Arrhenius decides to measure CO2 absorption to challenge the CO2 is saturated claim by Knut Angstrom.


Act III, Charlottenburg, BerlinAct III, Charlottenburg, Berlin19011901

Heinrich RubensSvante Arrhenius


Arrhenius travels to Berlin where Heinrich Rubens is an experienced experimentator with infrared gases.


Rubens' experimental setupRubens' experimental setup● Click to add an outline

This is the experimental setup. CO2 is released in a tube of 50 cm, with a rock salt window at each end.

The heat source is either a Lesley cube of 100 C or a basin of melting CO2 ice. The actual measurement is performed on a thermopile with a galvanometer


Flashback: Royal Institution, London Flashback: Royal Institution, London 1859-18721859-1872

John Tyndall


Arrhenius quotes the work of Tyndall who did a similar experiment in 1859.


Tyndall experiment setupTyndall experiment setupTyndall experiment setupTyndall experiment setup

This is the Experimental setup of John tyndall, he used a 4 foot tube, also fitted with rock salt windows. Note the two Lesley cubes for the differential setup.


Arrhenius vs Tyndall Arrhenius vs Tyndall

Arrhenius 1901 Tyndall 1872

Arrhenius brags how well the Tyndall data fit his own observations. However on close inspection Arrhenius divided the Tyndall values by a factor 3.6 to match them.

Arrhenius also did not report the discrepancy.


Arrhenius “adjusts” TyndallArrhenius “adjusts” Tyndall

Here is a graphical comparison: Original Tyndall values in blue, Arrhenius cited Tyndall in green, Arrhenius' own data in red. Comparison with Hitran data in purple.

I leave the Arrhenius claim to your judgment.



Rock salt is opaque at 25 micron (the far infrared), the original claim by Ramanathan is therefore physically impossible to measure.



Rubens and Arrhenius also used melting CO2 as a heat source. Rock salt transmission dramatically increases the absorption values because the spectral peak is truncated.


Arrhenius vs. ModtranArrhenius vs. Modtran

The green line is the measured effect for the cold source, Arrhenius calculated a value band (in blue) for the atmosphere, which is far steeper than a comparison with modtran (in black) based on real CO2 and water vapour values.


QuotesQuotes● Arrhenius' 1896 data go up to 30 micron● Due to strong absorption it is very difficult to measure Due to strong absorption it is very difficult to measure

infrared radiation using rock salt prisms beyond 20 micron. infrared radiation using rock salt prisms beyond 20 micron. Arrhenius' 1896 data goes up to 12 micron, and contains Arrhenius' 1896 data goes up to 12 micron, and contains mainly water vapour, this data is useless to calculate the mainly water vapour, this data is useless to calculate the absorption of CO2. absorption of CO2.

● Arrhenius' 1896 data stop at 3 micron ● AngstromAngstrom's data stop at 3 micron's data stop at 3 micron● The CO2 spectrum is saturated● The CO2 spectrum is not saturated, this argument originates The CO2 spectrum is not saturated, this argument originates

from Knut Angstrom who measured a solar spectrum where from Knut Angstrom who measured a solar spectrum where CO2 has only marginal absorption.CO2 has only marginal absorption.

Ramanathan & Vogelmann 1997 AMBIO, 26(1):38-46 Baliunas & Soon 1999 http://www.greeningearthsociety.org/climate/previous_issues/vol4/v4n19/cutting1.htmCourtney 2000 http://www.john-daly.com/solar/keldebat.htm


QuotesQuotes● Revised calculations, finding a somewhat lower effect, were

given in Arrhenius (1901) ● The 1901 calculated trend is dominated by two effects: The 1901 calculated trend is dominated by two effects: 1) A high absorption at low temperature due to infrared cutoff 1) A high absorption at low temperature due to infrared cutoff

by rock salt.by rock salt.2) Unreported reduction of the original observations by 2) Unreported reduction of the original observations by

Tyndall.Tyndall.

Arrhenius tuned the data in such a way that the new Arrhenius tuned the data in such a way that the new calculations confirmed his earlier work. Using modern data calculations confirmed his earlier work. Using modern data leads to a substantially lower CO2 absorption trend, and leads to a substantially lower CO2 absorption trend, and hence a far lower climate sensitivity. hence a far lower climate sensitivity.

Weart 2003 http://www.aip.org/history/climate/co2.htm


ConclusionsConclusions● Arrhenius:Arrhenius: The 1896 publication uses data without CO2, The 1896 publication uses data without CO2,

but mainly shows water absorption, due to the wrongly but mainly shows water absorption, due to the wrongly extrapolated refractive index of rock salt. The observations extrapolated refractive index of rock salt. The observations stop at 12 micron.stop at 12 micron.

● The high CO2 absorption trend calculated by Arrhenius in The high CO2 absorption trend calculated by Arrhenius in 1901 is influenced by the infrared cutoff of rock salt. 1901 is influenced by the infrared cutoff of rock salt.

● Arrhenius reduced Tyndall's data with a factor 3.6 to match Arrhenius reduced Tyndall's data with a factor 3.6 to match his own observationshis own observations without reporting this. without reporting this.

● Angstrom:Angstrom: The CO2 spectrum is not saturated, CO2 The CO2 spectrum is not saturated, CO2 absorption in the solar spectrum was below instrumental absorption in the solar spectrum was below instrumental detection.detection.


TRUST BUT VERIFYTRUST BUT VERIFY

Few people seem to have read the original publications, mainly because they are in German.


AcknowledgementsAcknowledgements● The librarians of the Utrecht and Delft universities● Solar spectra using SMARTS freeware from the Renewable

Resource Data Center ● Hitran online database at the Institute of Atmospheric

Optics, Tomsk, Russia● Modtran3 online (David Archer)● The conveners of this conference

This presentation was created using Open Office

Documents

Hans Erren - Elisa Ideat · Arrhenius' greenhouse effect with a prism of salt A historical review Hans Erren 12 September 2006 Global Warming - Scientific Controversies in Climate