Climatic condition

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Ice core data and the Quaternary cold and warm periods

The climate condition describes the condition of the climate system. Climate change describes the change in the climate that is determined by the energy budget of a planet.

The energy budget largely depends on the Milanković cycles . Climate change is influenced by eccentricity , the precession of the earth's axis of rotation , the inclination of the earth, the ecliptic , orogenesis , the state of the oceans , tectonics and human interventions in the environment. The orbital orientation of the earth is decisive for the intensity of solar radiation, especially in the northern hemisphere , which causes periodic climatic fluctuations.

Climatic fluctuations in the climate system are caused by processes in geospheric systems, which try to bring the non-equilibrium system into the thermodynamic equilibrium corresponding to the energy budget of the planet . Thermal energy and greenhouse gases in the atmosphere result in the potential tendency for the orientation towards climate change. The air conditioning system contains various tilting elements that are dependent on the water vapor feedback and ice-albedo feedback . Abrupt climate changes are non-linear processes in the climate system; these can be triggered after threshold values ​​have been reached.

Climatic conditions

Syukuro Manabe was the first to point out in 1988 that the earth's climate could have two stable states. The term "background-air state" (English background state ) describes the current climate state. In the history of the earth , the climate fluctuates between “greenhouse” ( warm periods ) and “ice house” conditions ( cold periods ). In climatology researchers also distinguish between the initial state or Paläozustand when it comes to determining the climate sensitivity and the radiative forcing is.

The “ snowball earth ” state explains the repeated glaciation of the entire globe during the Neoproterozoic 760 to 635 million years ago. The glaciation process at that time probably affected the entire earth from the poles to the equator including the oceans.

The “heat house” state is being discussed in connection with unchecked climate change on the planet Venus , and research is being carried out into whether this is also possible on earth. Hansen et al. calculated a climate sensitivity of 3 to 4 ° C in 2013 , based on a scenario of 550 ppm CO 2 . Burning all fossil fuels would lead to a global temperature increase of 16 ° C (with a warming of the atmosphere over the continents by an average of 20 ° C and over the poles by 30 ° C).

In various scientific literature, based on the two basic climates warm and cold, the climatic conditions are further subdivided into ice house , cool greenhouse , warm greenhouse and hot house ( icehouse , cool greenhouse, warm greenhouse, hothouse ). According to this, each of these climatic conditions has its own geophysical and climatic characteristics, which differ significantly from the others. In addition, several tipping points are assumed at the transition from ice house to cool greenhouse and from warm greenhouse to hot house , which can transform the earth's climate system into a new and partially irreversible state ( tipping elements in the earth system ).

Climate change

In order to be able to determine future climate change events more precisely, the connection between feedbacks with regard to climate sensitivity and climate condition is intensively researched. All feedbacks can trigger non-linear processes and thus disturb the climatic condition (or the background climatic condition ) and the radiative forcing.

Individual evidence

  1. ^ Tilting elements - Achilles' heels in the earth system. Potsdam Institute for Climate Impact Research , accessed on September 26, 2016 .
  2. ^ Walter Roedel: Physics of our environment - The atmosphere . 3. Edition. Springer, Heidelberg 2000, ISBN 3-540-67180-3 , 1.2 The solar radiation, p. 21 , Table 1.3 (some values ​​for the backscattering power - albedo - of the earth's surface) .
  3. ^ Thermodynamics: Albedo ( English ) In: All About Sea Ice . National Snow and Ice Data Center. Retrieved July 5, 2016.
  4. ↑ James Croll: Climate and Time in Their Geological Relations. A Theory of Secular Changes of the Earth's Climate. Appleton, New York 1885 ( books.google.de ).
  5. ↑ S. Manabe, RJ Stouffer: Two Stable Equilibria of a Coupled Ocean-Atmosphere Model . In: Journal of Climate . tape 1 , no. 9 , September 1, 1988, ISSN  0894-8755 , p. 841-866 , doi : 10.1175 / 1520-0442 (1988) 001 <0841: TSEOAC> 2.0.CO; 2 (English).
  6. ↑ Thomas Farmer and John Cook: Climate Change Science: A Modern Synthesis . tape 1 : The Physical Climate . Springer Wissenschaftsverlag, 2013, ISBN 978-94-007-5756-1 , 2.8 From Hothouse to Icehouse.
  7. ↑ a b James Hansen, Makiko Sato, Gary Russell, Pushker Kharecha: Climate sensitivity, sea level and atmospheric carbon dioxide . In: Philosophical transactions of the Royal Society of London / A . tape 371 , no. 2001 , October 28, 2013, ISSN  1364-503X , p. 20120294 , doi : 10.1098 / rsta.2012.0294 (English).
  8. ↑ Michael Marshall: Humans could turn Earth into a hothouse . tape 212 , no. 2839 . Elsevier, November 19, 2011, p. 10-11 , doi : 10.1016 / S0262-4079 (11) 62820-0 .
  9. ^ SI Rasool, C. De Bergh: The Runaway Greenhouse and the Accumulation of CO2 in the Venus Atmosphere . In: Nature . tape 226 , no. 5250 , June 13, 1970, pp. 1037-1039 , doi : 10.1038 / 2261037a0 .
  10. ↑ James F. Kasting: Runaway and moist greenhouse atmospheres and the evolution of Earth and Venus . In: Icarus . tape 74 , no. 3 , June 1988, pp. 472-494 , doi : 10.1016 / 0019-1035 (88) 90116-9 .
  11. ^ Kendall Powell & John Bluck: Tropical 'runaway greenhouse' provides insight to venus . NASA Ames Research Center, 2002 ( nasa.gov ).
  12. ↑ HC Fricke, C. Williams, JB Yavitt: Polar methane production, house climates, and climate change . American Geophysical Union, December 2009, bibcode : 2009AGUFMPP44A..02F .
  13. ↑ David L. Kidder, Thomas R. Worsley: A human-induced hothouse climate? . (PDF) In: GSA Today (The Geological Society of America) . 22, No. 2, February 2012, pp. 4-11. doi : 10.1130 / G131A.1 .
  14. ^ EJ Rohling, A. Sluijs, HA Dijkstra, P. Köhler, RSW van de Wal, AS von der Heydt, DJ Beerling, A. Berger, PK Bijl, M. Crucifix, R. DeConto, SS Drijfhout, A. Fedorov, GL Foster, A. Ganopolski, J. Hansen, B. Hönisch, H. Hooghiemstra, M. Huber, P. Huybers, R. Knutti, DW Lea, LJ Lourens, D. Lunt, V. Masson-Demotte, M. Medina -Elizalde, B. Otto-Bliesner, M. Pagani, H. Pälike, H. Renssen, DL Royer, M. Siddall, P. Valdes, JC Zachos , RE Zeebe: Making sense of palaeoclimate sensitivity . In: Nature . tape 491 , no. 7426 , November 2012, p. 683–691 , doi : 10.1038 / nature11574 (English, academiccommons.columbia.edu [PDF]).