Hothouse earth

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The terms greenhouse soil (English Hothouse Earth ) and hot-time call in the climate research (in particular the research on resilience ) a state of the earth's climate system beyond a planetary limit of about 2 ° C compared to the pre-industrial average temperature at which the system substantially of intrinsic biogeophysical feedback is driven. The long-term consequences would be enormous increases in temperature unprecedented in the past millions of years and a rise in sea level of 10–60 meters, with conditions hostile to life in large regions for humans and many other species. This is one of the possible scenarios for long-term global warming in the context of climate change , which is transforming the earth's climate system from the current interglacial into a warm climate .

In paleoclimatology , hothouse earth (more often greenhouse earth ) is often used as the opposite term to icehouse earth and in this context describes the transition from a warm climate to an ice age (or vice versa), whereby the term icehouse also refers to extreme cold phases such as the snowball earth stages can be extended.

Geological greenhouse phases

Climate history of the last 541 million years with extreme greenhouse phases in the Cretaceous and on the Permian / Triassic border (upper panel)

Extreme hot phases were not uncommon in the history of the earth and occurred - mostly in connection with a destabilization of the biosphere - repeatedly during the Phanerozoic . The earth is currently in a relatively cold phase. During the climatic optimum in the Cretaceous period, temperatures were three to four times the current CO 2 content, around 8 ° C higher than today.

With the Paleocene / Eocene temperature maximum and the Eocene Thermal Maximum 2 , there were two events in recent geological history in which the global temperature rose within a short period of time by about 6 ° C from 18 to 24 ° C. The causes and the exact duration of these periods are not exactly known, but have been linked to a significant increase in greenhouse gases . These heat events were associated with extensive periods of drought in the subtropics, but an increase in precipitation, especially in the polar regions. In addition, there was an oxygen depletion in the ocean and significant changes in terrestrial and marine biotopes .

Development paths in the Anthropocene

Tipping point

In climate research, there is broad consensus that there are tipping elements in the earth system , through which an irreversible trajectory is taken in the direction of an unusually warm climate for the Quaternary , with threatening consequences for humanity . However, different climate models come to different results as to the temperature at which this threshold lies. A meta - analysis by Steffen et al. In 2018 came to the conclusion that the 2-degree target set in the Paris Agreement might not be enough to stabilize the climate system. Instead, irreversible feedback threatens a development path whose final state could be a climate like in the Middle Miocene , which began around 16 million years ago and ended more than 11 million years ago - the first finds of upright homini are roughly at an age Dated 5 million years ago (→  human tribal history ). Steffen u. a. called this path the "greenhouse earth" path.

Influencing factors

There are a number of feedback effects that can result from the Quaternary climate. These effects are sometimes referred to as "domino effects". A rise in global temperatures is causing the permafrost in Russia, Canada and Northern Europe to thaw . This releases the greenhouse gas methane stored in the soil (in addition to carbon dioxide) . This release accelerates the greenhouse effect. that is, the temperatures rise even faster. Methane can also be released from methane hydrate deposits that are located under the ice caps at the North and South Poles and on the ocean floor. Furthermore, rising temperatures lead to ice melting at the poles. This reduces the albedo , which leads to the absorption of heat instead of re-radiation into space, which in turn leads to an even faster temperature rise in the water and thus to a further release of methane. When the temperature rises, parts of the rainforest also die . This in turn releases carbon dioxide. Here, too, there is an acceleration in the rise in temperature. Since water vapor also acts as a greenhouse gas, the evaporation that increases with the temperature (e.g. from sea water) represents a further accelerating component in the entire interaction spectrum ( water vapor feedback ). A rise in the temperature of the oceans also reduces their large absorption potential for carbon dioxide or causes its partial outgassing more quickly. Once again the temperature of the earth system rises.

According to researchers, the earth could warm up by four to five degrees due to the domino effect. This would also happen if the Paris Climate Agreement were successfully implemented. As a result, parts of the earth would then be uninhabitable.

Countermeasures

Collective human action is required to steer the earth's climate system away from a potential threshold and stabilize it in a habitable interglacial state; Such action includes responsibility for all elements of the earth system ( biosphere , climate , society ) and could include decarbonising the global economy, improving carbon sinks in the biosphere, changing behavior, technological innovations, new regulatory measures and changing social values .

Concept history

In 1824, Jean Baptiste Joseph Fourier described the effect that later became known as the greenhouse effect , but he did not yet use the term "greenhouse" ("greenhouse" or "hothouse"). Around 1860, John Tyndall and Eunice Newton Foote formulated the connection between an increase in atmospheric greenhouse gas concentrations and increasing temperatures on earth. Svante Arrhenius assumed around 1900 that increasing greenhouse gas concentrations due to the increasing combustion of coal and oil in the course of industrialization would intensify the natural greenhouse effect and would noticeably warm the climate over a period of a few centuries (→  Research History of Climate Change ). Arrhenius used in his 1906 work Världarnas utveckling in the context of the term "drivbänk" ("green house" in the German translation of 1907, "hothouse" in the English, 1908). The American physicist Robert Williams Wood was probably the first to use the term “greenhouse” in 1909. Both referred to the geophysical phenomenon of the greenhouse effect, but not past or threatening future climatic conditions in the sense of a hot period or a greenhouse climate.

The term "Hothouse earth" was used sporadically in the 1970s. The nuclear physicist Howard A. Wilcox used the term in 1975 as a metaphor for a warming of the earth by around 0.5–1.5 ° C within around 80 years, which in his opinion - reinforced by feedback - would be enough to achieve that To trigger melting of the polar ice caps.

The journalist Fred Pearce titled his popular science book published in 1990 on global warming as a result of the human intensification of the greenhouse effect with "greenhouse earth", without limiting the term more precisely.

After the drought and heat in Europe in 2018, the term “hot time” was chosen as word of the year by the Society for the German Language in December 2018 during the UN climate conference in Katowice .

Web links

Wiktionary: hot time  - explanations of meanings, word origins , synonyms, translations

literature

  • David L. Kidder, Thomas R. Worsley: A human-induced hothouse climate? In: GSA Today . February 2012, p. 4–11 , doi : 10.1130 / G131A.1 (open access).
  • Will Steffen, Johan Rockström, Katherine Richardson, Timothy M. Lenton, Carl Folke, Diana Liverman, Colin P. Summerhayes, Anthony D. Barnosky, Sarah E. Cornell, Michel Crucifix, Jonathan F. Donges, Ingo Fetzer, Steven J. Lade , Marten Scheffer, Ricarda Winkelmann & Hans Joachim Schellnhuber (2018). Trajectories of the Earth System in the Anthropocene . Proceedings of the National Academy of Sciences ; doi: 10.1073 / pnas.1810141115 .

Individual evidence

  1. ↑ a b c d Will Steffen et al .: Trajectories of the Earth System in the Anthropocene. In: Proceedings of the National Academy of Sciences . August 6, 2018 doi: 10.1073 / pnas.1810141115
  2. ↑ Elizabeth Griffith, Michael Calhoun, Ellen Thomas, Kristen Averyt, Andrea Erhardt, Timothy Bralower, Mitch Lyle, Annette Olivarez ‐ Lyle, Adina Paytan: Export productivity and carbonate accumulation in the Pacific Basin at the transition from a greenhouse to icehouse climate (late Eocene to early Oligocene) . In: Paleoceanography and Paleoclimatology . 25, No. 3, September 2010. doi : 10.1029 / 2010PA001932 .
  3. ^ PF Hoffman, AJ Kaufman, GP Halverson, DP Schrag: A Neoproterozoic Snowball Earth . (PDF) In: Science . 281, No. 5381, August 1998, pp. 1342-1346. doi : 10.1126 / science.281.5381.1342 .
  4. ↑ David PG Bond, Stephen E. Grasby: On the causes of mass extinctions . (PDF) In: Palaeogeography, Palaeoclimatology, Palaeoecology . 478, No. 15, July 2017, pp. 3–29. doi : 10.1016 / j.palaeo.2016.11.005 .
  5. ↑ Isabel Montanez, GS Soreghan: Earth's Fickle Climate: Lessons Learned from Deep-Time Ice Ages . In: Geotimes . 51, March 2006, pp. 24-27.
  6. ^ Gary Shaffer, Matthew Huber, Roberto Rondanelli, Jens Olaf Pepke Pedersen: Deep time evidence for climate sensitivity increase with warming . (PDF) In: Geophysical Research Letters . 43, No. 12, June 2016, pp. 6538-6545. doi : 10.1002 / 2016GL069243 .
  7. ↑ Alexander Gehler, Philip D. Gingerich, Andreas Pack: Temperature and atmospheric CO 2 concentration estimates through the PETM using triple oxygen isotope analysis of mammalian bioapatite . In: PNAS . 113, No. 28, July 2016, pp. 7739-7744. doi : 10.1073 / pnas.1518116113 .
  8. ^ Francesca A. McInerney, Scott L. Wing: The Paleocene-Eocene Thermal Maximum: A Perturbation of Carbon Cycle, Climate, and Biosphere with Implications for the Future . (PDF) In: Annual Review of Earth and Planetary Sciences . 39, May 2011, pp. 489-516. doi : 10.1146 / annurev-earth-040610-133431 .
  9. ↑ Holocene variability and Anthropocene rates of change. (pdf, 312 kB) In: Proceedings of the National Academy of Sciences of the United States of America . July 20, 2018, accessed December 16, 2018 .
  10. ↑ Maiken Nielsen: Climate Study: Steer on a "hot time". In: tagesschau.de . August 7, 2018, accessed December 16, 2018 .
  11. ^ Deutsche Welle (www.dw.com): Researcher: The world is threatened by a hot period | DW | 08/06/2018. Retrieved on March 24, 2020 (German).
  12. ↑ James R. Fleming: Historical Perspectives on Climate Change . Oxford University Press, 1998, ISBN 0-19-518973-6 , pp. 17, 61, 78-80 .
  13. ^ Eunice Foote: Circumstances Affecting the Heat in the Sun's Rays . In: The American Journal of the Science and Arts . tape 22 November 1856, XXXI, p. 382-383 . limited preview in Google Book search. See also: Spence Wheart: The Carbon Dioxide Greenhouse Effect. In: The Discovery of Global Warming. February 2018, accessed May 22, 2018 .
  14. ↑ Svante Arrhenius: Världarnas utveckling. 1906, accessed on August 17, 2020 : "Deras [Fouriers, Pouillets, Tyndalls] teori kallas för drifbänksteorien, emedan de antogo, att atmosfären inverkar på samma sätt som glaset i en drifbänk." German translation: The becoming of the worlds. Retrieved August 17, 2020 . English: Worlds in the Making. Retrieved August 17, 2020 . Actually the Swedish word "drivbänk" means the greenhouse box of Frühbeets , see also sv: Drivbänk
  15. ↑ Henning Rodhe, Robert Charlson, Elizabeth Crawford: Svante Arrhenius and the Greenhouse Effect . In: Ambio . tape 26 , no. February 1 , 1997.
  16. ^ Howard A. Wilcox: Hothouse Earth . Ed .: US Dept. of Defense, Navy's Ocean Farm Project. 1975 (Wilcox believed that a warming of approx. 0.5–1.5 ° C would result from the waste heat of an exponential growth in energy use. Even then, his theory was considered questionable and hardly received any reception in climate science (according to Google Scholar his book is cited 15 times since its publication until June 2020)).
  17. ↑ For contemporary criticism of Wilcox's thesis, see: Bayard Webster: Scientist Warns of Great Floods if Earth's Heat Rises. December 22, 1975. Retrieved June 13, 2020 . Or Hothouse Earth. In: Kirkus Book Reviews. October 1, 1975, accessed June 13, 2020 .
  18. ↑ Fred Pearce: Greenhouse Earth. The dangers of global climate change . Georg Westermann Verlag GmbH, 1990. ISBN 3-07-509238-X .
  19. ↑ Word of the year 2018: hot time. In: Inforadio . December 14, 2018, accessed December 16, 2018 .