Climate catastrophe

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Development of the global mean temperature over the past 2000 years.

Climate catastrophe is the term for a climate change with worldwide catastrophic effects. This also includes uncontrolled global warming , for example as a greenhouse-earth scenario. In the mass media in particular , the term is often used as a framework for interpreting the feared consequences of man-made climate change. In climate impact research, drastic consequences are sometimes referred to as climate disasters. Climate catastrophes serve as motifs in literature and film. The current political, social and technological climate crisis would, if not resolved, lead to a climate catastrophe.

Aspects and Mechanisms

In its fourth assessment report , the Intergovernmental Panel on Climate Change cites tipping elements and abrupt changes in the Earth system as possible causes of potentially catastrophic consequences. These include, among other things, a drastic rise in sea level that has persisted over many centuries , pronounced and rapid regional, abrupt climate changes due to a breakdown of the thermohaline circulation , crop failures due to frequent and extreme droughts or the breakdown of the Indian summer monsoon, and possibly rarer but more intense tropical cyclones .

Drastic changes in ocean currents, as well as the fact that the climate is a chaotic system equipped with many feedbacks , can lead to abrupt climate changes. If the warm Gulf Stream were to dry up, Central Europe would cool down considerably, which would lead to crop failures.

Hansen et al. a. 2013 calculate a climate sensitivity of (3–4 ° C) based on a 550 ppm CO 2 scenario, i. That is, he expects an atmospheric greenhouse gas concentration equivalent to a carbon dioxide concentration of 550 ppm, warming of 3-4 ° C. (If you add the greenhouse effect of carbon dioxide with the effect of other greenhouse gases, the concentration of which has been increased by humans, you get a CO 2 equivalent of 485 ppm for 2015. ) The burning of all fossil fuels would reduce the air over the continents on average Heat 20 ° C and the poles by 30 ° C. Most of the earth would become uninhabitable. The scenario of a galloping greenhouse effect ( runaway greenhouse effect ), which would lead to climatic conditions like on Venus and make the earth completely uninhabitable, he regards as being triggered by human activity but not.

Greater climate risks with greater global warming

The risk and extent of the consequences of climate change increase with the extent of warming. A warming of more than two degrees is often viewed as dangerous, which is why politicians have decided to limit the warming to two degrees, the so-called two-degree target . With increasing warming, the risk of catastrophic consequences, such as extreme weather events, increases disproportionately. The Stern Report names social upheavals, security risks and migration as possible catastrophic consequences of climate change when the temperature rises by 5 ° C.

Importance for climate protection measures

The threat of consequences of climate change, which are unlikely but would have catastrophic effects, plays a role in the economic discussion about limiting global warming. Since no experience is available for catastrophic global warming scenarios, damage estimates are not possible. Economic cost-benefit models of climate change do not capture these consequences when calculating an optimal emission path. A climate policy based on such emission paths would not rule out climate catastrophes with sufficient certainty. This is why some scientists, for example Martin Weitzman and, following him, Paul Krugman , suggest that more ambitious climate protection measures should be viewed as insurance against climate catastrophes.

Concept history

It had been known since the early 19th century that mass extinction had almost always occurred at the borders or transitions of geochronological periods . Until well into the 20th century, these biological crises and catastrophes were mostly explained by sea ​​level fluctuations , continental shifts, and climate and environmental changes. A well-known example is the dying of dinosaurs , about which there are several theories.

In 1956, in the run-up to the International Geophysical Year (1957/1958), Time Magazine referred to warnings from Roger Revelle that sustained CO 2 emissions could have severe effects on the climate in perhaps 50 years' time, and identified the potential for feedback amplification global warming, specifically a global rise in sea level caused by the melting of the Greenland and Antarctic ice sheets , as a "catastrophe". In the 1960s, the first scientific bodies warned that the release of CO 2 was unique in the history of the earth, that stabilizing mechanisms, such as carbon sinks , could reach their limits, and that man-made, ultimately “alarming” processes could be underway. In the 1970s and 1980s, scientific publications increasingly painted the picture of dangerous climate change caused by human greenhouse gas emissions and raised the question of the extent to which measures should be taken to prevent it.

Since 1977 at the latest, the term "climate catastrophe" has appeared again and again in warnings of human-made global warming. In December 1985, the Energy Working Group of the German Physical Society (DPG) warned of an impending climate catastrophe in a press release. A few months later, in a joint statement with the German Meteorological Society, the DPG published another warning of impending "climate change", in which the word catastrophe was no longer mentioned, but the climate change was described as "one of the greatest dangers for mankind", "apart from a war with nuclear weapons". The term "climate catastrophe" was picked up by the mass media and politics and the problem of climate change was often portrayed in a simplistic way as an impending catastrophe.

In 2007 and 2010, in the context of increasing reporting on climate change at the UN climate conferences in Bali and Copenhagen, the IPCC's Fourth Assessment Report and Al Gore's film An Inconvenient Truth , the term reappeared a little more frequently in the media but rarely used compared to terms like climate protection or climate change .

The word "climate catastrophe" was chosen as word of the year 2007 by the Society for German Language , because it characterizes "the threatening development that climate change is taking". A media association chose the word as one of the 100 words of the century because it was particularly indicative of the 20th century.

Criticism of the use of the term

Many scientists, even if they see the consequences of global warming as threatening, are reserved about the use of the term in the media for the consequences of global warming. They fear that their research results will be overly dramatized. For specific extreme catastrophe scenarios occasionally depicted in the media, such as the sudden escape of large amounts of methane hydrates and abrupt warming, scientists indicate that, although they cannot be ruled out in the near future, they are unlikely.

As climate deniers used to describe people who deny the human causes and the extent of global warming. Most of them are not climate scientists and consider an imminent climate catastrophe to be unlikely. Examples are Wolfgang Behringer and Fritz Vahrenholt .

Climate catastrophe and culture

A climate catastrophe is the subject of several films, e. B. Waterworld and The Day After Tomorrow , as well as the subject of documentaries such as An Inconvenient Truth and The Age of Stupid .

See also

literature

Web links

Wiktionary: Climate catastrophe  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  1. ↑ a b c Peter Weingart, Anita Engels, Petra Pansegrau: Risks of communication: discourses on climate change in science, politics, and the mass media . In: Public Understanding of Science . tape 9 , no. 3 , 2000, doi : 10.1088 / 0963-6625 / 9/3/304 .
  2. ↑ Intergovernmental Panel on Climate Change (Ed.): IPCC Fourth Assessment Report: Climate Change 2007 . Working Group III: Mitigation of Climate Change. 2.2.4 Risk of catastrophic or abrupt change ( ipcc.ch ). ipcc.ch ( Memento from May 2, 2010 in the Internet Archive )
  3. ↑ Stefan Rahmstorf: Rapid climate transitions in a coupled ocean-atmosphere model. In: Nature. 372, 1994, pp. 82-85. doi: 10.1038 / 372082a0 nature.com pik-potsdam.de (PDF)
  4. ↑ James Hansen et al. a .: Climate sensitivity, sea level and atmospheric carbon dioxide . In: Royal Society Publishing . tape 371 , September 2013, doi : 10.1098 / rsta.2012.0294 ( online - English). Climate sensitivity, sea level and atmospheric carbon dioxide ( Memento from September 17, 2013 in the web archive archive.today )
  5. ↑ Nicholas Stern: The Economics of Climate Change . Cambridge University Press, 2007, pp. 66-67, 71-72, 98-99 .
  6. ↑ Martin L. Weitzman: GHG Targets as Insurance Against Catastrophic Climate Damages . In: Journal of Public Economic Theory . tape 14 , no. 2 , March 27, 2012, doi : 10.1111 / j.1467-9779.2011.01539.x .
  7. ↑ Nicholas Stern: The Structure of Economic Modeling of the Potential Impacts of Climate Change: Grafting Gross Underestimation of Risk onto Already Narrow Science Models . In: Journal of Economic Literature . tape 51 , no. 3 , March 27, 2012, doi : 10.1257 / jel.51.3.838 .
  8. ↑ One Big Greenhouse . In: Time . May 28, 1956 (English, blogs.sfu.ca ).
  9. ↑ The Conservation Foundation (ed.): Implications of Rising Carbon Dioxide Content of the Atmosphere . A statement of trends and implications of carbon dioxide research reviewed at a conference of scientists. 1963, p. 63 (English). See also Research History of Climate Change # First Warnings .
  10. ↑ Hermann Flohn : Are we facing a climate catastrophe? In: Look around . 1977. after Franz Mauelshagen: The climate catastrophe . Scenes and scenarios. In: Gerrit Schenk (Ed.): Catastrophes. From the fall of Pompeii to climate change . Stuttgart 2009, p. 216 ( researchgate.net [PDF]).
  11. ↑ Hoimar von Ditfurth : The branch on which we sit. Part 1 The balance of the biosphere. In: Cross-section (series on ZDF ). November 8, 1978, accessed on May 18, 2020 (the information cited is only contained in the film itself, not in the synopsis: approx. 5:52 “heat climate catastrophe”, approx. 42:43 “climate catastrophe”).
  12. ↑ Klaus Heinloth : Energy for today and tomorrow . In: Physical sheets . tape 36 , no. 10 , 1980, doi : 10.1002 / phbl.19800361008 .
  13. ↑ Swiss National Commission for UNESCO, Swiss Natural Research Society (ed.): How we turn our earth into a greenhouse. On the way to the climate catastrophe caused by carbon dioxide . Bern 1983 ( edudoc.ch [PDF]).
  14. ^ Warning of a climate catastrophe . German Physical Society. Retrieved November 4, 2019.
  15. ↑ Joint appeal by the DPG and the DMG warning of impending global climate changes caused by humans . In: Deutsche Physikalische Gesellschaft, Arbeitskreis Energie (Hrsg.): Physikalische Blätter . tape 43 , no. 8 , August 1987, doi : 10.1002 / phbl.19870430811 .
  16. ↑ Reiner Grundmann, Mike Scott: Disputed climate science in the media: Do countries matter? In: Public Understanding of Science . 2012, doi : 10.1177 / 0963662512467732 .
  17. ^ Word of the year 2007: Climate catastrophe. Society for the German Language (GfdS), accessed on September 4, 2015 .
  18. ↑ David Archer: Methane hydrate stability and anthropogenic climate change . In: Biogeosciences . tape 4 , no. 4 , 2007, p. 521-544 , doi : 10.5194 / bg-4-521-2007 ( uchicago.edu [PDF; accessed May 25, 2009]).
  19. ↑ Wolfgang Behringer: Cultural history of the climate. From the ice age to global warming. Munich 2007, p. 281.
  20. ^ Fritz Vahrenholt: The catastrophe does not take place . In: Die Welt , October 7, 2013.