Climate engineering risks and uncertainties

Prof Johannes Quaas, Institute for Meteorology, Universität Leipzig

Abstract: Climate engineering, the aim at technically modifying the Earth's climate in order to mitigate climate change, comes at various risks and uncertainties, including legal, moral, ethical, and technical ones.

This talk will focus on the risks and uncertainties of climate engineering from a physical perspective. It will explain and discuss the following topics: The Paris climate conference has set a target maximum warming of 2°C. Given the very large uncertainty about climate sensitivity, this may imply a need for climate engineering. While in principle, the best way to do so might be carbon capture and sequestration, mostly climate engineering focuses on managing absorbed solar radiation.

Several of the proposed schemes exploit aerosols and their effects on radiation either directly or via alteration of clouds. However, we do not even understand how in the past climate has reacted to emissions of aerosol particles, both via their effect on radiation and via the modification of clouds.

There is some evidence about substantial alterations of important climate phenomena. Nevertheless, one can experiment with climate engineering using climate models. While in the model world in principle a climate change mitigation seems feasible, several important side effects are noted. A main risk is associated with a possibly necessary termination of a climate engineering measure. 

 

Panel discussion on Climate Engineering

Moderation: Svenja Rausch, MA, University of Cologne

Panelists:

Prof Boris Braun, Institute of Geography, University of Cologne,
Prof Astrid Kiendler-Scharr, Institute of Energy and Climate Research, Forschungszentrum Jülich,
Prof Johannes Quaas, Institute for Meteorology, Universität Leipzig
Prof Harry Vereecken, Scientific Director, Geoverbund ABC/J and Institute of Bio- and Geosciences, Forschungszentrum Jülich

Detailed programme:

• 17:00 - 17:05 Introduction of event, panelists and moderator (Prof Peter Dannenberg, scientific coordinator of the Cologne Geosciences Colloquium series)
• 17:05 - 17:30 Presentation on "Climate Engineering risks and uncertainties" (Prof J. Quaas) incl. time for questions directly related to the talk (moderation: S. Rausch)
• 17:30 - 17:45 Panel discussion; opening statements by participants and direct questions from moderator (S. Rausch)
• 17:45 - 18:15 Panel discussion; questions from members of the public (S. Rausch)
• 18:15 - 18:25 Closing statements (S. Rausch)
• 18:25 - 18:30 wrap-up (Prof P. Dannenberg)

18:30 - …     Time for personal discussions over drinks and snacks