Societal relevance of climate science Hans von Storch Institute of Coastal Research, Geesthacht and KlimaCampus, Hamburg Germany January Climate change in social sciences, Athens, Greece

Overview Climate Research – history The knowledge market Man-Made Climate Change - history Problem – high uncertainty, high stakes Postnormality

Climate research – history Anthropocentric view – climate determines living conditions; Climatic determinism Physics of atmosphere and of ocean Physics of climate Climate change – climate constrains living conditions

Alexander von Humboldt (1769–1859) Cosmos, A Sketch of a Physical Description of the Universe, 1845 “The term climate, taken in its most general sense, indicates all the changes in the atmosphere, which sensibly affect our organs, as temperature, humidity, variations in the barometrical pressure, the calm state of the air or the action of varying winds, the amount of electric tension, the purity of the atmosphere or its admixture with more or less noxious gaseous exhalations, and, finally, the degree of ordinary transparency and clearness of the sky, which is not only important with respect to the increased radiation from the earth, the organic development of plants, and the ripening of fruits, but also with reference to its influence on the feelings and mental condition of men”.

The case of Eduard Brückner – solid climate research but unexpected social and technological developments. Hans von Storch & Nico Stehr

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 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.). Klimaschwankungen und Völkerwanderungen Climate variability and mass migration Vortrag Kaiserliche Akademie der Wissenschaftern, Wien 1912 Precip  crop prod.

Map of „mental energy“ conditioned by climatic conditions Distribution of civilizations in 1916, according to expert opinion. E. Huntington 1876–1947 of Yale University

Davies‘ (1923, 1929 and 1932) „nose index“ derived from observations and estimated from temperature and humidity data.

Atmospheric and oceanic dynamics

Climate physics

Global temperature derived from thermometer data (CRU)

IPCC 2007 Auch mensch- gemachte Treibhausgase Nur natürliche Faktoren Messungen Explaining global mean surface air temperature

Scenarios, not predictions

Climate change – climate constrains living conditions Hasselmann, 1990

Policy advice Understanding climate dynamics and sensitivity leads directly to the „right“ policy. This is: concentrate on CO2, limit the emissions so that the temperature change is stabilized and limited to 2K in Create an international, binding agreement now. Discourse limited to one strategy, which is claimed as only solution. Recently clear that this strategy fails; new options (incl. adaptation) are discussed, e.g., Hartwell paper.

The science-.policy/public interaction is not an issue of „knowledge speaks to power“. The problem is not that the public is stupid or uneducated. A problem is that the scientific knowledge is confronted on the „explanation marked“ with other forms of knowledge (pre-scientific, outdated; traditional, morphed by different interests). Scientific knowledge does not necessarily “win” this competition. Problem is that science is presented as if there is a well- defined problem, which needs one specific “solution” The social process „science“ is influenced by these other knowledge forms. Knowledge market

There is a history of cultural constructions of anthropogenic climate change in the past 1000 years. Climate change studies have a history, and has seen many claims and falsifications. These claims have left traces in the public understanding of climate and climate change

Cases of claims of anthropogenic climate change Religious Interpretations [In medieval times, for instance, it was proposed that climatic anomalies, or extreme events, were a punishment for parishes which were too tolerant of witches. Of course, witches were believed to be able to directly cause adverse weather. ] Improving climate by human stewardship [oldest case documented by contemporary scientific writing refers to the climate of the North American colonies (Williamson, 1771); More cases during the medieval times, related to colonization by monks, are described by Glacken (1967)]

Tambora 1816 and lightning rods In many parts of Europe, the summer of 1816 was unusually wet, presumably because of the eruption of the volcano Tambora. However, people attributed the adverse conditions to the new practice of using lightning conductors. The case is documented in two articles published in the newspaper Neue Züricher Zeitung (21 June and 9 July 1816). The authorities called the concerns unsubstantiated and issued grave warnings concerning violent and illegal acts against the conductors.

Debate about climate change – in the late 19th century In the 19th century scientists in Europe and in North America were confronted with the concept that the climate would be constant on historical time scales. But then, scientists found significant differences between mean precipitation and temperature when averaged over different multi-year periods (e.g. Brückner, 1890). Scientists claimed that the water levels of rivers would fall continuously. This led to the detection of non-constant climatic conditions and to the hypothesis that the observed changes are caused by human activities, mainly deforestation or reforestation. A debate was hold about two alternative explanations, namely a systematic climate change mainly related to deforestation or unknown cosmic drivers, on time scales of decades of years. It seems that the majority adopted the concept of man-made causes over the natural variability hypothesis.

In 1836 Rivière advocated the theory of deforestation for parts of southern France 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. The question of climate change due to destruction of forests has been raised in France many times, e.g. it was 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. 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.” E. Brückner: Klimaschankungen seit E.D. Hölzel,Wien, 1890

The cooling After World War II scientists noticed a cooling and some speculated about whether this cooling was brought on by human actions, mostly emissions of dust and industrial pollution. It was speculated that human pollution would increase by a factor of as much as 8 which could increase the opacity of the atmosphere within hundred years by 400%. This would reduce incoming sun light causing the global mean temperature to sink by 3.5 C. Such a cooling would almost certainly be enough to force Earth into a new Ice Age (Rasool and Schneider, 1971).

Cases of claims of anthropogenic climate change Rerouting Siberian rivers [In Russia, plans for re- routing Siberian rivers southward have been discussed since the beginning of this century. The plans visualize benefits in supplying semi-arid regions with water. A byproduct was thought to be an ice-free Arctic ocean; the increase of evaporation from the open water would transform the Arctic climate into a maritime climate with moderate temperatures and busy harbors along the Soviet Union’s North coast.] Rerouting ocean currents [Riker suggested in 1912 changing the Gulf Stream with the purpose of improving the climate not only in North America but also the Arctic and Europe. The idea of modifying ocean currents was later pursued by scientists from the USA, USSR and other nations. ]

Cases of claims of anthropogenic climate change Creating of Lakes [in Africa] Deforestation Emission of aerosols [e.g., first Iraq war and burning oil wells] Detonation of nuclear bombs in the 1940s/50s.

Competition of knowledge claims

Lund and Stockholm Two different construction of „climate change“ – scientific and cultural – which is more powerful? Cultural: „Klimakatastrophe“ Scientific: man-made change is real, can be mitigated to some extent but not completely avoided Storms

“How strongly do you employ the following sources of information, for deciding about issues related to climate adaptation?” Regional administrators in German Baltic Sea coastal regions. Bray, 2011, pers. comm. Which construction „wins“ in the public domain?

Science under postnormal conditions Jerry Ravetz, Silvio Funtovicz, 1986 and earlier State of science, when facts uncertain, values in dispute, stakes high and decisions urgent. Climate science is postnormal, see Bray and von Storch, 1998 In this state, science is often not done for reasons for curiosity but is asked for as support for preconceived value-based agendas. Compares with various environmental cases, such as nuclear power, BSE etc. A tool found for helping to introduce a more rationale and acceptable discourse: “extended peer review” of procedures, quality control.

Challenge for climate science Determination of role of science in a postnormal situation Is Merton‘s CUDOS a Leitbild for climate science, or is it … … the scientist, who provides truth and guidance for solving societal problems? Climate science is partly natural science, partly social, partly cultural science. Without coaching by cultural sciences, the role of climate sciences will be reduced to the linear (reduced) model (cf. Hulme, 2011), and fail to provide societies with the necessary knowledge for dealing with the challenge of man-made climate change.

The prize of politicization of climate science Acting as support for a political agenda may help the this agenda, but utilizes the capital of science, namely public trust. The issue is a matter of sustainable usage of the capital of science.

Historical sciences should deal with climate and the practise of its scientific analysis and policy advice. Natural climate scientists are social actors, who operate in a social and cultural context. Many believe, they are objective, and free of such “cultural ballast”