Transcript Klimaschankungen seit 1700.

The case of
Eduard Brückner
– solid climate
research but
unexpected
social and
technological
developments.
Hans von Storch
& Nico Stehr
Overview:
a) Eduard Brückner
b) How constant is today‘s climate?
c) Debate about climate change
d) Practical importance of climate
fluctuations
e) Conclusions
f) Brückner-Award 2003
Eduard Brückner
Born July 29, 1863 in Jena, Germany, he died
at the age of 65 in l927 in Vienna, Austria. He studied at
the universities of Dorpat (now: Tartu, Estonia), Dresden,
and Munich and completed his doctorate under Albrecht
Penck in Munich with a dissertation on the ice fields in the
Salzach region in Austria. On the strength of his
dissertation, be was appointed professor of geography at
the University of Bern. He left Switzerland in 1904 for
two years at the University of Halle in Germany and
finally moved to the University of Vienna.
Brückner in 1890 published the first
extensive book-length discussion of climate fluctuations
in "historical times". He credits the head of the Bavarian
meteorological services, C. Lang, with the discovery of
decadal scale climate variability in a study of the climate
of the Alps.
Also interesting are his articles on the social
consequences arising from the climate fluctuations, such
as migration patterns, or on harvests, the balance of
trade of countries and shifts in the political predominance
of nations.
Brückner's methods are mainly limited to the
exploratory statistical analysis of time series in
combination with what might be called common sense. He
is unfamiliar with dynamical arguments (for instance,
concerning the geostrophic wind) and he was unaware of
theories concerning the general circulation of the
atmosphere.
Inwieweit ist das heutige Klima konstant?
How constant is today’s climate?
Verhandlungen des VIII Deutsche Geographentages,
Berlin 1889
“The graphical charts are based on observations from a total of 111
meteorological stations. The lustra averages of rainfall were determined
for each station and expressed in percentages of the thirty-year mean
of 1851 - 80; the averages of each country based on data from several
stations were then smoothed according to the following formula:
(a+2b+c)/4.
The curves of the chart give a clearer picture of the data
trend. A rise and fall of the curve by one increment refers to an
increase and decrease of rain by 5%. The distance between the top and
the bottom of each curve shows the amplitude of the variation, in
relative not in absolute terms. The wider the gap, the greater the
difference between the maximum and minimum amount of rainfall.“
Stations with precipitation data available to Brückner
•
Scotland, 16 stations
•
England, 9 stations
•
Northern France, 11 stations
•
Northern Germany, 21 stations
•
Austria-Hungary, 8 stations
•
West Russia, 6 stations
•
East Russia, 8 stations
(Arbroath, Laurick Castle, Loch Leven Sluice, Northesk Reservoir, Glencrose, Swanton, Fernielaw, Edingburgh,
Inveresk, Haddington, Culloden, Sandwich, Arrdaroach, Castle Toward, Cameron House and Bothwell Castle).
(Chillgrove, Nash Mills, Oxford, Exeter, Orleton, Podehale, Boston, Bolton and Kendal).
(Rouen, Paris, Vendôme, Pannetière, La Collancelle, Clamecy, Avallon, Laroche, Montbard, Poully and Dijon).
(Kleve, Trier, Köln, Boppard, Gütersloh, Frankfurt a. M., Gießen, Bremen, Kiel, Heiligenstadt, Torgau, Dresden,
Stettin, Berlin, Küstrin, Frankfurt a. O., Posen, Görlitz, Breslau, Königsberg I. Pr. and Tilsit).
(Bodenbach, Prague, Deutschbrod, Lemberg, Kremsmünster, Klagenfurt, Vienna, and Hermannstadt).
(Helsingfors, St. Petersburg, Riga, Warschau, Moskau and Kiew).
(Lugan, Simferopol, Astrachan, Baku, Tiflis, Bogoslows, Jekatherinenburg and Slatoust).
•West Sibiria, 1 station
(Barnaul).
•East of Sibiria, 3 stations
(Nertschinsk, Nikolajewsk/Amur and Peking).
•United States, North America, Interior, 9 stations
(Toronto/Ont., Milwaukee/Wis., Detroit/Mich., Madison/Jo., Steubenville/Ohio, Marietta/Ohio, Cincinatti/Ohio,
Leavenworth/Ka. and St. Louis/Miss.).
•Central Italy, 7 stations
(Parma, Modena, Bologna, Genua, Florence, Siena and Rome).
•India, 4 stations
(Madras, Calcutta, Jablapur and Bombay).
•Mauritius, 1 station
(S. Louis, Alfred-Observatorium.)
•Australia, 7 stations
(Adelaide, Bathurst, Bukelong, Deniliquin, Goulburn, Melbourne and Sydney).
Number of severe winters in a series of
20 winters
10
8
6
4
2
0
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
“
We were able to identify general variations of the climate. At first
glance it may seem unusual that these variations had escaped scientific scrutiny
to this day. However, there has been speculation about them before: every now
and then, based on unusual sightings at some source or body of water the view
emerged in publications that the climate of certain locations, their rainfall in
particular, was probably subject to periodic changes (e.g., Hann for the area of
the Caspian Sea, Schweinfurth for parts of the Mediterranean countries, and
most of all Fritz for many areas on the globe). The universal occurrence of the
phenomenon, its global importance and simultaneous course could by strictly
meteorological standards not be verified to this date, before a large number of
meteorological stations had recorded the dry period of the 60s and the wet
period around 1880.
These general climatic variations are the key to the prevalent great
confusion about the issue of climate changes, which we attempted to describe at
the beginning: they are the explanation for the fact that such contradictory
opinions could exist side by side: the climate changes over time first in one
direction and, then again, in another — the climate fluctuates and with it
fluctuate rivers, lakes and glaciers.”
Inwieweit ist das heutige Klima konstant?
Verhandlungen des VIII Deutsche Geographentages, Berlin 1889
Debate about climate change
Very old and wide-spread is the opinion that forests have an important impact on
rainfall. And indeed, a priori, this seems quite likely.
First of all forests are natural barriers to wind-driven air masses, which are then,
as when encountering hills and mountains, forced to rise. No matter how light this
upward drift may be, in theory it will have to lead to more condensation at its
windward side. But the forest’s influence is also felt in the fact that the air above
stays relatively humid. Forests slow down the swift runoff of the rainwater and
store the water in the ground which is then evaporated back into the air through
the tree tops. This process again must bring about an increase in precipitation
above the forest, the more so as because of the strong friction between wind and
forest surface and the resulting delay in air flow the moist air tends to stagnate
above the forest. If forests enhance the amount and frequency of precipitation
simply by being there, deforestation as part of agricultural expansion everywhere,
must necessarily result in less rainfall and more frequent droughts. This view is
most poignantly expressed by the saying: Man walks the earth and desert follows
his steps!
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
Perhaps no other area on earth has been mentioned more often in connection with the effects
of deforestation on rainfall than the regions of the Mediterranean Sea, and the increasingly
drier climate since pre-historic times which were interpreted as a general phenomenon, has
been attributed more frequently to man’s localised destructive efforts of turning woodland
into arable land. And indeed, if we compare the previously prosperous cultural life along the
eastern shores of the Mediterranean Sea with the Orientals’ bare existence in those areas
today, we are struck by the tremendous cultural decline and are only too readily inclined to
see its causes in what saps our own energy upon arrival in the orient: the scorching dry heat.
To today’s cultural leaders who live in the cool, wet northern hemisphere it seems
inconceivable that the blossoming antique culture could have prospered under the present
climatic conditions of the orient: the climate must have grown warmer and dryer since
antiquity. Consequently, the clear-cutting of forests carried out in these regions since ancient
times offers a convenient explanation: man has destroyed his own culture by destroying the
forests and has devastated the land, on which he is now left with a meagre existence. A
comparison between descriptions of the landscape as it used to be and as it is today appears
to confirm this situation.
But it was often overlooked that in antique times the descriptions of the subtropical
environment were done by its inhabitants while today’s scientific efforts take mainly place in
the temperate climate zones of Europe. The inhabitant of a southern country had to see the
same phenomena with different eyes and painted them in different colours than the
inhabitant north of the Alps.
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
“
It is not surprising that under such circumstances the issue of a link between
forests and climate has now and then been addressed by governments. Lately, the Italian
government has been paying special attention to reforestation in Italy and its expected
improvement of the climate. Father Denza emphasises the goal of such replanting efforts
with these few words: It must be prevented that periods of heavy rainfall alternate with
droughts.
It was often believed that the climate in Germany had improved since the early
ages, resulting in less cloud cover and precipitation from increasing deforestation. And, in
fact, a comparison of the rather gloomy description of ‘Germania’, as for instance given by
Tacitus, with the Germany of today seemed to point to a climate change; it was not taken into
consideration though that this Roman’s portrayal, naturally, had to be subjectively distorted.
But even in recent times multiple efforts have been made to prove a link between changes in
the climate and deforestation for parts of Central Europe. Van Bebber expresses views along
this line in his publication on rainfall in Germany, and so does Studniška for Bohemia.
According to Wessely, in Hungary the climate of the steppe has been gradually advancing
since the lifetime of Maria Theresia. In his opinion, resolute reforestation measures alone
promise help in preventing the impending drought.
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
In 1836 Rivière advocated the theory of deforestation for parts of southern
France, namely the Vendée, the Provence, and particularly the Départment du Var, at
the Academy in Paris; frost damage followed by the clearing of olive tree plantations
has presumably caused a considerable reduction in rainfall and dried-up springs in the
years from 1821 to 22. A similar situation exists in the former Poitou and the
Department of the lower Charente according to Fleuriau de Bellevue. Actually, the
question of climate change due to destruction of forests has been raised in France
many times, i.e. in 1858 by Ladoucette, who pointed out before the French Chamber of
Deputies that the climate of the Départements Pyrénées Orientales and the Hérault
had turned dryer and warmer after the destruction of forests. Because of these
reports the French legislature took a serious look at the subject of reforestation.
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
In the Unites States deforestation plays an important role as well and is seen as the
cause for a reduction in rainfall, which is believed to have been observed in the New England
States and also in the Pacific States; F. B. Hough in his capacity as committee chairman of the
American Association for Advancement of Science demands decisive steps to extend
woodland in order to counteract the increasing drought.
In 1873, in Vienna, the Congress for Agriculture and Forestry discussed the problem
in detail; and when the Prussian house of representatives ordered a special commission to
examine a proposed law pertaining to the preservation and implementation of forests for
safeguarding, it pointed out that the steady decrease in the water levels of Prussian rivers
was one of the most serious consequences of deforestation only to be rectified by
reforestation programs. It is worth mentioning that at the same time or only a few years
earlier the same concerns were raised in Russia as well and governmental circles reconsidered
the issue of deforestation.”
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
Practical importance of climate fluctuations.
“Are climate variations so significant that they
are of practical impact? Indeed they are.”
In dry areas in particular where water is notoriously scarce the hydrographic
conditions change dramatically during periods of climatic variations. Lakes disappear
during dry periods and reappear during wet ones, as for instance Lake George in New
South Whales which in 1820 and again in 1876, and to a lesser extent in 1850, used to be a
large lake of 12 to 18 kilometres in length, 10 kilometres in width, and 5 to 8 meters in
depth, yet disappeared completely in the dry periods in between; or some central African
lakes such as the Tshad, Tanganyika and Nyassa, which at times rise so high that their
overflowing waters create an outlet lasting for some years and which then lose this outlet
again when the dry period begins. Rivers and creeks dry out for a full decade; swamps dry
up and reappear in the next wet period.
Consequently climatic variations deeply affect human life. River navigation to a
great extent depends on the amount of water in the river bed which determines its depth.
In those dry years around 1830 and 1860 shipping problems increased and soon a lot of
speculation began about the possible cause of the lower river-water levels. In most cases
the increasing practice of deforestation was found to be the source. Now we know better:
it is because of climatic changes.
Another way in which temperature variations are affecting traffic is through
the length of time of the rivers’ freeze-up. For example, during the cold spill from 1806—
1820 the Newa and the harbor of St. Petersburg remained blocked by ice for more than
three weeks longer than they did during the warm period from 1821—1835. This means
that during cold years harbors in a more westerly location and with shorter closure times
handle part of St. Petersburg’s shipping traffic which they lose again during warm
periods. Thus certain changes in shipping traffic go hand in hand with climate changes.
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
Anomalies of length of ice-free periods
30
20
10
0
-10
173 41-- 46-- 51-- 56-- 61-- 66-- 71-- 76-- 81-- 86-- 91-- 96-- 180 06-- 11-- 16-- 21-- 26-- 31-- 36-- 41-- 46-- 51-- 56-- 61-- 66-- 71-- 76-6-- 45 50 55 60 65 70 75 80 85 90 95 00 1-- 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80
40
05
-20
-30
Siberia
Ural
N.-Russia
Baltic Provinces
SE-Russia
SW-Russia
StatesN-America
Mean Values
Klimaschankungen seit 1700.
E.D. Hölzel,Wien, 1890
Michigan
1880/83
Hamburg
1884/87
D J F M A MJ J A S O N D J F M A M J J A S O N D
Annual cycle of groundwater
Annual cycle of typhus
Der Einfluß der Klimaschwankungen auf die Ernteerträge und Getreidepreise in Europa
Influence of climate variability on harvest and grain prices in Europe.
Geographische Zeitschrift, 1895
Klimaschwankungen und Völkerwanderungen
Climate variability and mass migration
Vortrag Kaiserliche Akademie der Wissenschaftern,
Wien 1912
Variability of Rainfall and Wheat
Prices in England
Rainfall (R) is indicated in deviations
from mean (percentages) (1 = 2.5%),
the annual average wheat price (W) in
Shillings per Imp. Quarter (1 = 2 sh.).
Variability of Rainfall in
Relation to the Grain Crop in
Prussia
The Grain Crop (WZ = Wheat
Crop, RO = Rye Crop) is in
percentages of an average
crop, i.e. in deviation from a
multi-year mean ( 1 indicator =
5% deviation); rainfall (R) is
also in deviations (%) from the
mean (1 indicator = 4%).
Variability of Rainfall and Emigration
from the German Empire to the
United States
The curves are based on five-year
totals. Rainfall is in deviations
(percentages) from the multi-year
mean. Emigration to the United States
is in 10,000.
Variability of Rainfall in the United States and
Western Europe and the Total Number of
Immigrants to the U.S. and from Britain.
The curves are based on five year totals. The
number of immigrants is given in 10,000, rainfall in
deviation (percentages) from the multi-year mean..
CONCLUSIONS
Our discussion of climate variability and climate change at the end of the 19th century leads to a number of
conclusions which we consider relevant on methodical, theoretical and practical grounds:
(1) The debate on natural climate variability and anthropogenic climate change is not new. A similar debate,
almost forgotten today, was going on a century ago. The protagonists were in a situation similar to that of contemporary
scientists. Brückner reminds us of contemporary "activist" scientists. Brückner overlooked that he did not have the
expertise to predict the societal response to adverse climatic conditions, to cope with adverse conditions by improving
hygienic standards (the typhoid forecast), by perfecting the railway system (the forecast concerning the ice on the rivers)
or by allowing for artificial watering of agricultural land (the forecast concerning harvests).
(2) One of the noteworthy features of the early debate on the nature and consequences of climate change
among climatologists, geographers and meteorologists is also the degree to which even then intellectual boundaries among
scientific fields prevented the participants from incorporating perspectives and findings dealing with exactly the same
phenomena that had been advanced in other disciplines. After all, there had been for decades a lively and vigorous debate
among philosophers and in the emerging social sciences about the impact of climatic conditions on psychological and social
processes. The main assertions of this debate ultimately proved to be inconclusive and were rejected not only as onedimensional, first at the turn of the twentieth century in France and German and later in the United States, but also as
irrelevant to the distinctive claims advanced by social science discourse. That is, the domains of the physical and the social
milieu had become successfully separated in science.
(3) In the end a consensus emerged among climatologists that in "historical times" the global climate has been
constant; that neither a warming trend nor a trend toward less precipitation can be observed. The singular preoccupation in
the debate about climate variations one hundred years ago was the periodicity of observed fluctuations in temperature and
precipitation, not any secular climate as signaled by an increase in the volume of CO2 in the atmosphere. That such a
possibility, as the result of increased usage of fossil fuels, indeed existed was discussed alongside Brückner's 35-yearperiod theory in a textbook on cosmic physics by Svante A. Arrhenius (1903). However, none of the climatologists of the
day took up the challenge. Instead, they agreed that climate change was not a significant matter and soon other issues
began to dominate scientific discussions and public discourse.
Brückner-Award 2003
Die Klimaforschung hat eine lange Tradition und hat eine Reihe von Metamorphosen
durchgemacht. In klassischen Zeiten stand die Wirkung des mittleren atmosphärischen
Zustandes auf den Menschen im Vordergrund, später entstand die Klimatographie und
schließlich eine Palette von sich zumeist unabhängig entwickelnden disziplinären
Sichtweisen in Fächern wie Geologie, Meteorologie, Geographie oder Ozeanographie. Erst
unter dem Eindruck drohender anthropogener Klimaänderungen im letzten Jahrzehnt und
dem unmittelbaren Beratungsbedarf von Politik und Gesellschaft beginnen diese Disziplinen
sich aufeinander zu zu bewegen. Tatsächlich kann das "Klimaproblem" nicht als
Forschungsgegenstand etwa vorrangig der Meteorologie verstanden werden. Einerseits muß
das Verstehen des Klimas als geophysikalische Herausforderung gesehen werden.
Andererseits wird die Wahrnehmung und tradiertes Wissen von Klima Gegenstand sozialund kulturwissenschaftlicher Forschung, weil Klima Gegenstand öffentlichen Interesses
und öffentlicher Sorge geworden ist.
Um diesen Prozeß der interdisziplinären Verbreiterung der Klimaforschung zu fördern,
wird anläßlich der 6. Deutschen Klimatagung im September 2003 zum zweiten Male der
Eduard Brückner-Preis für herausragende interdisziplinäre Leistungen in der
Klimaforschung vergeben. Das Preisgeld in Höhe von 1500 € ist von InterResearch, dem Verleger der Zeitschrift "Climate Research", gespendet worden.
Der Preisträger wird von den aus den Professoren Egger, Negendank,
Sündermann, von Storch und Wanner nach Vorschlägen aus dem Kreis
der Klimaforscher ausgewählt. Vorschläge werden in schriftlicher Form
bis zum 1. August 2003 an Hans von Storch ([email protected]) erbeten.
Erster Brücker-Preisträger
Christian Pfister, Klimahistoriker, Bern
Zahllos sind die Hypothesen und Theorien, die über
Änderungen des Klimas in der Vergangenheit aufgestellt
wurden und naturgemäß mehr oder minder lebhaft das
Interesse weiterer Kreise in Anspruch nahmen, lässt doch
der strenge Nachweis einer in vergangenen Zeiten vor sich
gegangenen Änderung des Klimas sofort den Gedanken an
die Möglichkeit einer zukünftigen Änderung auftauchen;
eine solche aber könnte sich nicht ohne einschneidende
Wirkung auf das wirtschaftliche Leben der Völker
vollziehen.
Brückner (1890:2)