---
id: people/hans-joachim-schellnhuber
about:
  label: Hans Joachim Schellnhuber
  depiction: people/hans-joachim-schellnhuber.jpg
  depiction_credit: 'Foto Hollin, Wikimedia Commons, CC BY-SA 3.0.'
  description: >-
    German physicist who founded the Potsdam Institute for Climate Impact
    Research and led it from 1992 to 2018; known for work on tipping elements in
    the climate system.
  tags:
    - climate
    - tipping points
    - complex systems
person:
  affiliation: International Institute for Applied Systems Analysis (IIASA)
  role: climate scientist
  homepage: 'https://www.pik-potsdam.de/members/john'
provenance:
  origin: agent
  sources:
    - title: Hans Joachim Schellnhuber (Wikipedia)
      url: 'https://en.wikipedia.org/wiki/Hans_Joachim_Schellnhuber'
    - title: Hans Joachim Schellnhuber (PIK member page)
      url: 'https://www.pik-potsdam.de/members/john'
  created: '2026-11-02'
  reviewed: '2026-11-02'
  reviewed_by: 'Claude, from the sources listed'
  status: draft
---
Hans Joachim "John" Schellnhuber, born 7 June 1950, is a German physicist.[^1] He took a doctorate in theoretical physics at the University of Regensburg in 1980 and was a postdoctoral fellow at the Institute for Theoretical Physics in Santa Barbara; from solid state physics he moved into complex systems and nonlinear dynamics.[^1,2] He was the founding director of the [Potsdam Institute for Climate Impact Research](/organizations/pik-potsdam/), which he led from 1992 to 2018, and director emeritus until 2024.[^2] Since December 2023 he has been Director General of the International Institute for Applied Systems Analysis (IIASA) in Laxenburg, Austria.[^2] He has also been research director of the Tyndall Centre in England and an external professor at the Santa Fe Institute.[^1,2]

Wikipedia credits him with helping to create the analysis of tipping elements in the climate system, the "burning embers" diagrams of risk and the budget approach to emissions.[^1] In 1995 he proposed the 2 °C guardrail for global warming, later adopted by Germany, the European Union and, after Copenhagen in 2009, governments worldwide.[^1] He initiated the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), in which more than 30 research teams compare their simulations of climate impacts on water, floods and crops.[^1] Since 2019 his work has turned to the built environment and regenerative architecture, and he founded Bauhaus Earth.[^2]

He appears in the entry on [PIK](/organizations/pik-potsdam/).