Parallel Session 2.2: Climate engineering: What goes up must come down

Wednesday, 09:00 - 10:30
01 I Großer Saal

What goes up must come down. If we pump particles into the stratosphere, how will that effect air quality at the ground level? Solar geoengineering may also reduce the self-cleansing capacity of the near-surface atmosphere, allowing pollution to build up.  Alternatively, some aspects of air pollution may actually be reduced.

 

Talks:

  • Seb Eastham - Overview of links between CE and air quality
    • Climate engineering methods have the potential to modify every aspect of atmospheric composition and behavior. Most work to date has focused on climate variables such as temperature and precipitation, but air quality will also be affected, whether directly or indirectly. This talk will introduce a few possible mechanisms by which either SRM or CDR could impact surface air quality, before diving more deeply into distributional aspects and public health tradeoffs associated with stratospheric ozone depletion which might result from some CE methods.
       
  • Lauren Marshall - SRM: fate of stratospheric aerosol
    • Large stratospheric volcanic eruptions are the natural analogue for solar radiation management by sulfate aerosol. The eruption of Mt. Tambora in 1815 had significant climate impacts, leading to the 1816 ‘Year Without a Summer’ and resulted in one of the strongest and most easily identifiable volcanic signals in polar ice cores. As part of the Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP), four state-of- the-art global aerosol models simulated this eruption. We analyse the simulated volcanic sulfate deposition and compare to ice cores. We find that the deposited sulfate varies in timing, spatial pattern and magnitude between the models. We also present results from a large ensemble of stratospheric volcanic eruptions with different latitudes, SO2 emission magnitudes and emission column heights, which result in a broad range of global patterns and magnitude of deposited sulfate. These results highlight uncertainties and difficulties in predicting the fate of stratospheric aerosol arising from explosive volcanism.
       
  • David Keith - Local air quality risks from direct air capture of CO2
    • David Keith will present data from measurements of particulate matter released by Carbon Engineering’s pilot plant and speculate about the air quality impacts of commercial scale projects using similar technology.
  • Lili Xia - SRM impacts on ground level ozone (note: this talk will be held by Alan Robock)

    • We examine the potential effects of stratospheric sulfate aerosol and solar insolation reduction on tropospheric ozone and ozone at Earth’s surface. Despite nearly identical global mean surface temperatures for the two SRM approaches, solar insolation reduction increases global average surface ozone concentrations while sulfate injection decreases it. The difference is due to ozone transported from the stratosphere to the troposphere and the different tropospheric photochemical environment. In conclusion, surface ozone and tropospheric chemistry would likely be affected by SRM, but the overall effect is strongly dependent on the SRM scheme.

Convened by: 

Tim Butler

Organisation: 
Institute for Advanced Sustainability Studies (IASS) & Freie Universität Berlin
Country: 
Germany

Tim Butler obtained his PhD in 2003 at the University of Melbourne, Australia on the topic of the global atmospheric methane budget. After several years of postdoctoral research experience at the Max Plank Institute for Chemistry in Mainz, Germany, he joined IASS Potsdam to lead a research group with a focus on air pollution modelling. He is also a guest professor at the Freie Universität Berlin.

Simone Tilmes

Organisation: 
National Center for Atmospheric Research
Country: 
USA

Dr. Simone Tilmes is a Project Scientist II at National Center for Atmospheric Research (NCAR) and the liaison for the Community Earth System Model (CESM) chemistry-climate working group. Her scientific interests cover the understanding and evaluation of chemical, aerosol and dynamical processes in chemistry-climate models. She has investigated past, present and future evolution of the ozone hole in both hemispheres based on models and observations. Further research includes interactions in tropospheric chemistry, aerosols, air quality, long-range transport of pollutants, and tropospheric ozone. She also studies the impact of geoengineering on the Earth’s climate system, the hydrological cycle, and the impact of solar radiation management on dynamics and chemistry in both troposphere and stratosphere.

Sebastian Eastham

Organisation: 
Harvard University
Country: 
USA

Sebastian Eastham is a research scientist at the MIT Laboratory for Aviation and the Environment. His work focuses on developing and applying atmospheric models and methods to investigate compositional and public health impacts arising from anthropogenic emissions, especially those at high altitude.

Speakers: 

Lauren Marshall

Organisation: 
University of Leeds
Country: 
United Kingdom

Lauren is a final year PhD student in the Institute for Climate and Atmospheric Science at the University of Leeds, studying the impact of volcanic aerosol on the climate. She uses state-of- the-art global aerosol models to simulate a variety of volcanic eruptions and is interested in their impact on atmospheric chemistry, climate and the deposition of sulfate aerosol, in particular to the Greenland and Antarctic ice sheets.

David Keith

Organisation: 
Harvard University
Country: 
United States of America

David Keith has worked near the interface between climate science, energy technology, and public policy for twenty-five years. He took first prize in Canada's national physics prize exam, won MIT's prize for excellence in experimental physics, and was one of TIME magazine's Heroes of the Environment. David is Professor of Applied Physics in Harvard’s School of Engineering and Applied Sciences and Professor of Public Policy in the Harvard Kennedy School, and founder at Carbon Engineering, a company developing technology to capture of CO2 from ambient air to make carbon-neutral hydrocarbon fuels. Best known for work on the science, technology, and public policy of solar geoengineering, David is leading the development of an interfaculty research initiative on solar geoengineering at Harvard. David’s work has ranged from the climatic impacts of large-scale wind power to an early critique of the prospects for hydrogen fuel. David’s hardware engineering projects include the first interferometer for atoms, a high-accuracy infrared spectrometer for NASA's ER-2, and currently, development of CO2 capture pilot plants for Carbon Engineering. David teaches courses on Science and Technology Policy and on Energy and Environmental Systems where he has reached students worldwide with an online edX course. He has writing for the public with A case for climate engineering from MIT Press. Based in Cambridge, David spends about a third of his time in Canmore Alberta.

Lili Xia

Organisation: 
Rutgers University
Country: 
USA

Lili Xia is a Postdoctoral Research at Rutgers University working with Dr. Alan Robock. She graduated in 2014 with a Ph.D from Atmospheric Sciences Graduate Program at Rutgers University – New Brunswick. She has been working on climate change impact on agriculture, ecosystem, and air pollutants (e.g. surface ozone). She is also interested in the interaction between land and atmosphere through biosphere.

Alan Robock

Organisation: 
Rutgers University
Country: 
United States of America

Dr. Alan Robock is a Distinguished Professor of climate science in the Department of Environmental Sciences at Rutgers University. He graduated from the University of Wisconsin, Madison, in 1970 with a B.A. in Meteorology, and from the Massachusetts Institute of Technology with an S.M. in 1974 and Ph.D. in 1977, both in Meteorology. Before graduate school, he served as a Peace Corps Volunteer in the Philippines. He was a professor at the University of Maryland, 1977-1997, and the State Climatologist of Maryland, 1991-1997, before coming to Rutgers. Prof. Robock has published more than 370 articles on his research in the area of climate change, including more than 220 peer-reviewed papers. His areas of expertise include geoengineering, climatic effects of nuclear war, effects of volcanic eruptions on climate, and soil moisture. He serves as Editor of Reviews of Geophysics, the most highly-cited journal in the Earth Sciences. His honors include being a Fellow of the American Geophysical Union, the American Meteorological Society (AMS), and the American Association for the Advancement of Science, and a recipient of the AMS Jule Charney Award. Prof. Robock was a Lead Author of the 2013 Working Group 1 Fifth Assessment Report of the Intergovernmental Panel on Climate Change (awarded the Nobel Peace Prize in 2007). He recently served as a member of the Board of Trustees of the University Corporation for Atmospheric Research, which operates the National Center for Atmospheric Research.