Adjustments to Climate Perturbations—Mechanisms, Implications, Observational Constraints

AGU Advances, vol. 5

Abstract

Abstract Since the 5th Assessment Report of the Intergovernmental Panel on Climate Change (AR5) an extended concept of the energetic analysis of climate change including forcings, feedbacks and adjustment processes has become widely adopted. Adjustments are defined as processes that occur in response to the introduction of a climate forcing agent, but that are independent of global‐mean surface temperature changes. Most considered are the adjustments that impact the Earth energy budget and strengthen or weaken the instantaneous radiative forcing due to the forcing agent. Some adjustment mechanisms also impact other aspects of climate not related to the Earth radiation budget. Since AR5 and a following description by Sherwood et al. (2015, https://doi.org/10.1175/bams‐d‐13‐00167.1 ), much research on adjustments has been performed and is reviewed here. We classify the adjustment mechanisms into six main categories, and discuss methods of quantifying these adjustments in terms of their potentials, shortcomings and practicality. We furthermore describe aspects of adjustments that act beyond the energetic framework, and we propose new ideas to observe adjustments or to make use of observations to constrain their representation in models. Altogether, the problem of adjustments is now on a robust scientific footing, and better quantification and observational constraint is possible. This allows for improvements in understanding and quantifying climate change.

Authors 28

1. Johannes Quaas corresponding

   Leipzig University

   Affiliation as printed

   Leipzig Institute for Meteorology Leipzig University Leipzig Germany

2. Timothy Andrews

   Met Office

   Affiliation as printed

   Hadley Centre Met Office Exeter UK

3. Nicolas Bellouin

   Centre National de la Recherche Scientifique · Sorbonne Université · Institut Pierre-Simon Laplace · University of Reading

   Affiliation as printed

   Department of Meteorology University of Reading Reading UK

   Institut Pierre‐Simon Laplace Sorbonne Université/CNRS Paris France

4. Karoline Block

   Leipzig University

   Affiliation as printed

   Leipzig Institute for Meteorology Leipzig University Leipzig Germany

5. Oliviér Boucher

   Centre National de la Recherche Scientifique · Sorbonne Université · Institut Pierre-Simon Laplace

   Affiliation as printed

   Institut Pierre‐Simon Laplace Sorbonne Université/CNRS Paris France

6. Paulo Ceppi

   Imperial College London

   Affiliation as printed

   Imperial College London London UK

7. Guy Dagan

   Hebrew University of Jerusalem

   Affiliation as printed

   Hebrew University Jerusalem Jerusalem Israel

8. Sabine Doktorowski

   Leipzig University

   Affiliation as printed

   Leipzig Institute for Meteorology Leipzig University Leipzig Germany

9. Hannah Marie Eichholz

   Leipzig University

   Affiliation as printed

   Leipzig Institute for Meteorology Leipzig University Leipzig Germany

10. Piers M. de F. Forster

    University of Leeds

    Affiliation as printed

    University of Leeds Leeds UK

11. Tom Goren

    Bar-Ilan University · Leipzig University

    Affiliation as printed

    Bar Ilan University Ramat Gan Israel

    Leipzig Institute for Meteorology Leipzig University Leipzig Germany

12. Edward Gryspeerdt

    Imperial College London

    Affiliation as printed

    Imperial College London London UK

13. Øivind Hodnebrog

    CICERO Center for International Climate Research

    Affiliation as printed

    CICERO Oslo Norway

14. Hailing Jia Aachen SRON Leiden The Netherlands

    Space Research Organisation Netherlands · Leipzig University

    Affiliation as printed

    Leipzig Institute for Meteorology Leipzig University Leipzig Germany

    SRON Leiden The Netherlands

15. Ryan J. Kramer

    Goddard Space Flight Center · NASA Earth Science · University of Maryland, Baltimore County

    Affiliation as printed

    Earth Sciences Division NASA Goddard Space Flight Center Greenbelt MD USA

    GESTAR‐II University of Maryland Baltimore County Baltimore MD USA

16. Amanda C. Maycock

    University of Leeds

    Affiliation as printed

    University of Leeds Leeds UK

17. Johannes Mülmenstädt

    Pacific Northwest National Laboratory

    Affiliation as printed

    Pacific Northwest National Laboratory Richland WA USA

18. Gunnar Myhre

    CICERO Center for International Climate Research

    Affiliation as printed

    CICERO Oslo Norway

19. Fiona M. O’Connor

    Met Office · University of Exeter

    Affiliation as printed

    Department of Mathematics and Statistics Global Systems Institute University of Exeter Exeter UK

    Hadley Centre Met Office Exeter UK

20. Robert L. Pincus

    Lamont-Doherty Earth Observatory · Columbia University

    Affiliation as printed

    Lamont‐Doherty Earth Observatory Columbia University New York NY USA

21. Bjørn Hallvard Samset

    CICERO Center for International Climate Research

    Affiliation as printed

    CICERO Oslo Norway

22. Fabian Senf

    Leibniz Institute for Tropospheric Research

    Affiliation as printed

    Leibniz Institute for Tropospheric Research Leipzig Germany

23. Keith Peter Shine

    University of Reading

    Affiliation as printed

    Department of Meteorology University of Reading Reading UK

24. Chris Smith

    University of Leeds · International Institute for Applied Systems Analysis

    Affiliation as printed

    International Institute for Applied Systems Analysis Laxenburg Austria

    University of Leeds Leeds UK

25. Camilla W. Stjern

    CICERO Center for International Climate Research

    Affiliation as printed

    CICERO Oslo Norway

26. Toshihiko Takemura

    Kyushu University

    Affiliation as printed

    Kyushu University Fukuoka Japan

27. Velle Toll

    University of Tartu

    Affiliation as printed

    University of Tartu Tartu Estonia

28. Casey James Wall

    University of Oslo

    Affiliation as printed

    University of Oslo Oslo Norway