SPARC Workshop on “Solving the Mystery of Carbon Tetrachloride” in Zurich, 5-6 Oct 2015

Abstract submission deadline: 31 July 2015, Registration deadline: 24 Aug 2015


Carbon tetrachloride (CCl4 or CTC) is a major ozone-depleting substance and greenhouse gas. However, estimated CTC sources and sinks are inconsistent with abundance observations. Recent work suggests that there is a large unknown CTC source of about
39 Gg yr-1 and a 35-year lifetime. This workshop’s purpose is to bring together science, industry, and technology experts to exchange information and to coordinate research activities across disciplines for fully closing the CTC budget. This workshop will involve solicited and submitted presentations related to all aspects of the CTC problem.


1. Emissions or Sources:

  • CTC consumption and production for both historic and current usage
  • CTC feedstock usage, and potential fugitive emissions
  • Legacy emissions from brown-field sites
  • Top-down global and regional emissions estimate for CTC

2. Loss Processes: Photochemical, ocean, and soil losses of CTC

3. Observations: CTC measurements from ground stations, aircraft, balloon, satellite,
and ships to constrain the CTC budget

4. Modeling: Reconciling the emission and loss processes of CTC with observations in a global modeling perspective

Invited Keynote Speakers:

David Sherry (Nolan Sherry & Associates Ltd., UK): Industrial usage of CTC
Lambert Kujipers (TEAP/UNEP, NL): Production and emissions
Matt Rigby (University of Bristol, UK): Top-down emissions estimate for CTC
Jim Butler (NOAA, USA): Ocean losses of CTC
Steve Montzka (NOAA, USA): Overview of CTC observations
Qing Liang (NASA/USRA, USA): Global modeling of CTC

The outcome of the workshop will be summarized in the SPARC newsletter. We will strongly encourage all participants to reformulate their presentations into written papers. From these presentation and papers, we plan to organize a peer-reviewed special issue on all aspects of the CTC problem.


31 July 2015: Abstract Deadline.

24 August 2015: Registration Deadline.

5-6 October 2015: Workshop

Meeting venue and logistics:

The workshop will be held at Empa and hotel room blocks are reserved at a nearby hotel (Hotel Sonnental).

Meeting fee: 250 CHF (will be collected in cash at the meeting).

Hotel Sonnental
Zürichstrasse 94 / 96
8600 Dübendorf
T +41 44 802 12 82
F +41 44 821 41 91

Organizing Committee:

Stefan Reimann (Empa, Switzerland), Paul Newman (NASA, USA),
Qing Liang (USRA/NASA, USA)

For more information on this SPARC activity, please visit the following link at: