Understanding climate
for the benefit of society

Vilhelm Bjerknes and his son Jacob engaged with the public to teach science, but also to learn about their needs. Today's Bjerknes scientists are just as eager to share their research stories. 

Climate feedbacks and prospects for their evaluation

Climate simulation models include more and more processes – not only physical, but also biogeochemical cycles. Can single individuals keep an overview of the major factors governing climate change? Christoph Heinze has led a study that can help you. He presents the new article here. 


Written by Christoph Heinze from the Bjerknes Centre, the Geophysical Institute at the University of Bergen, and NORCE.

Advanced climate models are the tool for projections of climate change under typical forcing scenarios. These advanced climate models or Earth system models include - next to physical processes - also biogeochemical cycles and in particular the carbon cycle.

Even for climate researchers, it is difficult to keep an overview of climate relevant processes in the various compartments of the Earth system and their role in amplifying or reducing climate change for a given forcing.

In this article, the relevant positive and negative feedback processes are summarised by experts in the respective fields. In addition, the reference forcing for quantifying feedbacks, the feedback concept, and methods for evaluating the feedbacks are discussed.

The article should help to perceive the necessary complexity of climate models and to realise that a reality check of these models is a challenge but not out of scope – in spite of their complexity.

The paper should be understandable for scientists across all disciplines, educated non-experts, and students. The paper is a joint effort over a period of one decade. The author group and the senior authors have partly changed over this period. The authors hope that the article will motivate further development and appropriate use of Earth system models for tackling major societal challenges.


Christoph Heinze, Veronika Eyring, Pierre Friedlingstein, Colin Jones, Yves Balkanski, William Collins, Thierry Fichefet, Shuang Gao, Alex Hall, Detelina Ivanova, Wolfgang Knorr, Reto Knutti, Alexander Löw, Michael Ponater, Martin G. Schultz, Michael Schulz, Pier Siebesma, Joao Teixeir, George Tselioudis, and Martin Vancoppenolle: ESD Reviews: Climate feedbacks in the Earth system and prospects for their evaluationEarth Syst. Dynam., 10, 379–452, 2019, https://doi.org/10.5194/esd-10-379-2019