Und sie erwärmt sich doch! – Anmerkungen zur Klimaforschung: Von den ersten Schritten bis zum Nobelpreis für Physik

<p>Systematische wissenschaftliche Untersuchungen über das Klima der Erde begannen am Anfang des 19. Jahrhunderts. Der erste, der in den 1820er Jahren die These aufstellte, dass die Atmosphäre wie eine Decke wirkt und die Erdoberfläche wärmer hält, als sie sein sollte, war Joseph Fourier. Er beschrieb, was wir heute als Treibhauseffekt bezeichnen. Eine experimentelle Untersuchung der Strahlungsabsorption von CO<sub>2</sub> wurde erstmals von Eunice Foote im Jahr 1856 durchgeführt. Drei Jahre später zeigte John Tyndall die Absorption infraroter Strahlung durch CO<sub>2</sub> und Wasserdampf. 1896 berechnete Svante Arrhenius die Auswirkung einer Verdoppelung des CO<sub>2</sub> auf die Lufttemperatur an der Oberfläche auf 5-6°C. In seinen Berechnungen von 1931 reduzierte Hurlburt diesen Anstieg auf 4 °C.</p> <p>Das erste umfassende Strahlungs-Konvektions-Modell für die Atmosphäre wurde 1967 von Manabe und Wetherald vorgestellt. Sie zeigten, dass eine Erhöhung des CO<sub>2</sub>-Gehalts in der Atmosphäre zu einer Erwärmung in der Troposphäre und einer Abkühlung in der Stratosphäre führt, wie die Beobachtungen zeigen. Manabe war die treibende Kraft bei der Entwicklung umfassender Modelle des Klimas und der Erdsysteme in den kommenden Jahrzehnten. Für seine Beiträge zum Verständnis des Klimasystems, insbesondere der Rolle von CO<sub>2</sub>, wurde er 2021 mit einem Viertel des Nobelpreises für Physik ausgezeichnet.</p> <p>Lange Zeit war nicht klar, wie man das Signal des steigenden atmosphärischen CO<sub>2</sub> in den Temperaturaufzeichnungen in den verrauschten Daten von Wetter- und Klimaschwankungen finden kann. Im Jahr 1976 schlug Hasselmann vor, dass Änderungen der langsamen Klimavariablen durch das weiße Rauschen des atmosphärischen Wetters verursacht werden. In den 1990er Jahren entwickelte er auch Methoden, um die "Fingerabdrücke" menschlicher Einflüsse auf die Klimavariabilität zu finden. Diese Methoden wurden intensiv auf die jüngsten Klimaintegrationen angewandt, die verschiedene Zukünfte des Klimas der Erde beschreiben. Auf der Grundlage dieser Anwendungen können wir nun feststellen, dass sich die Erde erwärmt - und wir daran schuld sind. Für seine Beiträge zum Verständnis der stochastischen Natur des Klimasystems und des menschlichen Fingerabdrucks auf die Klimaerwärmung wurde Klaus Hasselmann ein Viertel des Nobelpreises für Physik 2021 verliehen.</p>

Émile Zola and the Literary Language of Climate Change

On 7 February 1861, John Tyndall, professor of natural philosophy, delivered a historical lecture: he could prove that different gases absorb heat to a very different degree, which implies that the temperate conditions provided for by the Earth's atmosphere are dependent on its particular composition of gases. The theoretical foundation of climate science was laid. Ten years later, on the other side of the Channel, a young and ambitious author was working on a comprehensive literary analysis of the French era under the Second Empire. Émile Zola had probably not heard or read of Tyndall's discovery. However, the article makes the case for reading Zola's Rougon-Macquart as an extensive story of climate change. Zola's literary attempts to capture the defining characteristic of the Second Empire led him to the insight that its various milieus were all part of the same ‘climate’: that of an all-encompassing warming. Zola suggests that this climate is man-made: the economic success of the Second Empire is based on heating, in a literal and metaphorical sense, as well as on stoking the steam-engines and creating the hypertrophic atmosphere of the hothouse that enhances life and maximises turnover and profit. In contrast to Tyndall and his audience, Zola sensed the catastrophic consequences of this warming: the Second Empire was inevitably moving towards a final débâcle, i.e. it was doomed to perish in local and ‘global’ climate catastrophes. The article foregrounds the supplementary status of Tyndall's physical and Zola's literary knowledge. As Zola's striking intuition demonstrates, literature appears to have a privileged approach to the phenomenon of man-induced climate change.

Seeing is (Dis)believing

The backbone of Victorian spirit investigations rested with the credibility of the witnesses who attended spiritualist events such as séances. But how did someone become a credible witness of spirit or psychic phenomena? What were the processes by which their testimonies became trustworthy representations of genuine experiences? This paper explores these questions by examining the visual epistemology of the scientific naturalist and sceptic John Tyndall (1820–1893), as a way of understanding the politics of constructing scientific testimony during the late Victorian period. Visual epistemology can be defined as an embodied practice of observation that moves beyond merely being the physical act of looking at things to include a range of skilled activities. Key to this paper is an attempt to challenge earlier whiggish accounts in the historiography that have perpetuated the myth that science conquered spiritualism in the nineteenth century. Instead, it exposes a more complicated narrative about Victorian science’s uneasy relationship with spirit and psychic phenomena, and raises important questions about the authority and limit of scientific naturalism.

Lone Voices?

This chapter asks if Draper and White were indeed the sole originators of the conflict thesis, or whether there were others before and/or alongside them. Journeying from the French Revolution through to late Victorian England, key players are identified and discussed. These include Auguste Comte, Herbert Spencer, John Tyndall, Thomas Huxley, the X Club, and many more influential characters who spoke on or wrote about the relationship between science and religion. The conclusion is that Draper and White were far from alone: many other highly significant public figures had argued that there was an inherent conflict between theology and the scientific method in one way or another. The chapter then teases why it might be that Draper and White are so forcefully put forward in the literature as being the lone progenitors of the idea.

James Croll and 1876: an exceptional year for a ‘singularly modest man’

ABSTRACT James Croll left school at the age of 13 years, yet while a janitor in Glasgow he published a landmark paper on astronomically-related climate change, claimed as ‘the most important discovery in paleoclimatology’, and which brought him to the attention of Charles Darwin, William Thomson and John Tyndall, amongst others. By 1867 he was persuaded to become Secretary and Accountant of the newly established Geological Survey of Scotland in Edinburgh, and a year after the appearance of his keynote volume Climate and time in 1875, he was lauded with an honorary doctorate from Scotland's oldest university, Fellowship of the Royal Society of London and Honorary Membership of the New York Academy of Sciences. Using a range of archival and published sources, this paper explores aspects of his ‘journey’ and the background to the award of these major accolades. It also discusses why he never became a Fellow of his national academy, the Royal Society of Edinburgh. In the world of 19th-Century science, Croll was not unusual in being both an autodidact and of humble origins, nor was he lacking in support for his endeavours. It is possible that a combination of Croll's modesty and innovative genius fostered advancement, though this did not hinder a willingness to engage in vigorous argument.

Cosmic connections: James Croll's influence on his contemporaries and his successors

ABSTRACT This paper examines the astronomical theory of ice ages of James Croll (1821–1890), its influence on contemporaries John Tyndall, Charles Lyell, and Charles Darwin, and the subsequent development of climate change science, giving special attention to the work of Svante Arrhenius, Nils Ekholm, and G. S. Callendar (for the carbon dioxide theory), and Milutin Milanković (for the astronomical theory). Croll's insight that the orbital elements triggered feedbacks leading to complex changes – in seasonality, ocean currents, ice sheets, radiative forcing, plant and animal life, and climate in general – placed his theory of the Glacial Epoch at the nexus of astronomy, terrestrial physics, and geology. He referred to climate change as the most important problem in terrestrial physics, and the one which will ultimately prove the most far reaching in its consequences. He was an autodidact deeply involved in philosophy and an early proponent of what came to be called ‘cosmic physics’ – later known as ‘Earth-system science.’ Croll opened up new dimensions of the ‘climate controversy’ that continue today in the interplay of geological and human influences on climate.