EESS talk on "The physics and chemistry of aerosols for potential injection into the stratosphere to cool the planet"
Event details
| Date | 29.10.2024 |
| Hour | 12:15 › 13:15 |
| Speaker | Dr.Thomas Peter,Institute for Atmospheric and Climate Science, ETH Zürich. |
| Location | Online |
| Category | Conferences - Seminars |
| Event Language | English |
Abstract:
How well do we know the physicochemical properties of aerosols that are considered for injection into the stratosphere to cool the climate? Eighteen years after Paul Crutzen’s proposition for research on increasing the planet’s albedo by injecting sulfur into the stratosphere, detailed knowledge is still limited about the conversion of sulfur-containing gases (SO2, H2S) into aqueous sulfuric acid droplets, let alone about mechanisms of other potential species such as calcite or alumina under stratospheric conditions. While the scientific community’s reaction to Crutzen’s 2006 proposal to explore such environmental engineering has ranged from skepticism to outright rejection, even in the mid-2020s there is little hope that global greenhouse gas emissions can be reduced fast enough to meet the 1.5-degree goal set out in the 2015 Paris Agreement, and even the 2-degree target is seriously at stake. Apart from the global governance, legal, and ethical issues that need to be adequately addressed before any deployment of stratospheric aerosol injections can be considered, we must be prepared to compare the uncertainties and risks of an injection system with those of nom-deployment, as long as greenhouse gas emissions continue unabated and efficient techniques for negative emissions are not yet within reach. To this end, this presentation will examine the physical and chemical aspects of the general problem, i.e. the behavior of injected particles under the harsh conditions in the stratosphere. A particular focus will be on the impact of aerosol injection on the global ozone layer, comparing injections of sulfuric acid droplets, calcite particles, or alumina particles and assessing the relative uncertainties associated with each.
Biogaphy:
Tom Peter is Professor Emeritus of Atmospheric Chemistry at the Institute for Atmosphere and Climate at ETH Zurich. With his research group, he investigated the fundamentals of aerosols and clouds, their physical processes and chemical reactions, their influence on the composition of the air, on the global atmosphere and on Earth’s climate.
How well do we know the physicochemical properties of aerosols that are considered for injection into the stratosphere to cool the climate? Eighteen years after Paul Crutzen’s proposition for research on increasing the planet’s albedo by injecting sulfur into the stratosphere, detailed knowledge is still limited about the conversion of sulfur-containing gases (SO2, H2S) into aqueous sulfuric acid droplets, let alone about mechanisms of other potential species such as calcite or alumina under stratospheric conditions. While the scientific community’s reaction to Crutzen’s 2006 proposal to explore such environmental engineering has ranged from skepticism to outright rejection, even in the mid-2020s there is little hope that global greenhouse gas emissions can be reduced fast enough to meet the 1.5-degree goal set out in the 2015 Paris Agreement, and even the 2-degree target is seriously at stake. Apart from the global governance, legal, and ethical issues that need to be adequately addressed before any deployment of stratospheric aerosol injections can be considered, we must be prepared to compare the uncertainties and risks of an injection system with those of nom-deployment, as long as greenhouse gas emissions continue unabated and efficient techniques for negative emissions are not yet within reach. To this end, this presentation will examine the physical and chemical aspects of the general problem, i.e. the behavior of injected particles under the harsh conditions in the stratosphere. A particular focus will be on the impact of aerosol injection on the global ozone layer, comparing injections of sulfuric acid droplets, calcite particles, or alumina particles and assessing the relative uncertainties associated with each.
Biogaphy:
Tom Peter is Professor Emeritus of Atmospheric Chemistry at the Institute for Atmosphere and Climate at ETH Zurich. With his research group, he investigated the fundamentals of aerosols and clouds, their physical processes and chemical reactions, their influence on the composition of the air, on the global atmosphere and on Earth’s climate.
Practical information
- General public
- Free
- This event is internal
Organizer
- EESS - IIE
Contact
- Prof. Tamar Kohn, LEV