Representative concentration path

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Scenarios of atmospheric CO 2 equivalent concentrations of all greenhouse gases (in PPM per volume) according to the four RCPs according to the fifth IPCC assessment report.

The term representative concentration path (Engl. Representative concentration pathway , therefore abbreviated RCP ) is since the Fifth Assessment Report of the Intergovernmental Panel on Climate (IPCC) to describe scenarios for the course of absolute greenhouse gas concentration used in the atmosphere.

Scenarios

In the fifth assessment report, four scenarios are identified, which are designated as RCP2.6, RCP4.5, RCP6 and RCP8.5 in accordance with the assumed range of radiative forcing in the year 2100 (e.g. 2.6 W / m 2 ). RCP2.6 corresponds to a scenario with clear efforts in climate protection , which also include efforts in the area of negative emissions ; RCP8.5 corresponds to a “business as usual” scenario, which is also referred to as “misleading” due to its low probability of occurrence. Scientists at the Woods Hole Research Center see this scenario as realistic and meaningful. It corresponds to the cumulative historical CO 2 emissions and it fits best with the current and announced climate policy until the middle of the 21st century.

The numerical values ​​should not be misinterpreted as values ​​for an expected increase in temperature; Rather, a rise in temperature is the consequence of the radiative forcing expressed by the values ​​due to increased greenhouse gas concentrations. The values ​​also do not relate to the annual greenhouse gas emissions, but to the cumulative total amount expressed by the greenhouse gas concentration up to the year 2100 or the radiative forcing resulting therefrom.

Model calculations from 2019 show that even if the RCP4.5 scenario, which is assessed as optimistic, occurs, many cities would migrate to another climate zone; For example, the climate in Madrid, Spain, would be more similar to the current climate in Marrakech, Morocco in 2050 than it is today in Madrid, and the climatic conditions from Stockholm to those of Budapest, London to Barcelona, ​​Moscow to Sofia, Seattle to San Francisco change analogously, Tokyo to Changsha.

literature

  • IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, RK Pachauri and LA Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.

credentials

  1. ↑ Zeke House Father, Glen P. Peters: Emissions - the 'business as usual' story is misleading . In: Nature . tape 577 , January 29, 2020, p. 618–620 , doi : 10.1038 / d41586-020-00177-3 : "We must all - from physical scientists and climate-impact modellers to communicators and policymakers - stop presenting the worst-case scenario as the most likely one. Overstating the likelihood of extreme climate impacts can make mitigation seem harder than it actually is. This could lead to defeatism, because the problem is perceived as being out of control and unsolvable. "
  2. ↑ Christopher R. Schwalm, Spencer Glendon, Philip B. Duffy: RCP8.5 tracks cumulative CO 2 emissions . In: Proceedings of the National Academy of Sciences . August 3, 2020, doi : 10.1073 / pnas.2007117117 .
  3. ↑ J.-F. Bastin et al .: Understanding climate change from a global analysis of city analogues. In: PLoS One. No. 14 (7), 2019, e0217592. https://doi.org/10.1371/journal.pone.0217592