This document discusses using atmospheric measurements of halocarbons to support emission inventories used in international agreements aimed at addressing ozone depletion and global warming. It lists various halocarbons including CFCs, HCFCs, HFCs, and others. Measurement networks like AGAGE and NOAA/ESRL monitor these gases globally. Models can combine measurements with information on gas lifetimes to estimate emissions on regional and country scales. Recent studies have applied these methods to verify national inventories and identify unknown emission sources. Atmospheric measurements provide a real-world check on inventories and help build trust between countries. Standardized measurement and analysis techniques are important to support emission estimates.

1. Stefan Reimann
Martin K. Vollmer
Stephan Henne
Dominik Brunner
Alistair Manning (UK MetOffice)
Lukas Emmenegger
Source attribution of halogenated compounds in support
of emission inventories for international agreements
stefan.reimann@empa.ch

2. • Chlorofluorocarbons (CFCs)
CFC-11, CFC-12 , CFC-13, CFC-11, CFC-113
• Halons
H-1301, H-1211, H-2402, CH3Br
• Solvents
CH3CCl3, CCl4,
• Hydrochlorofluorocarbons (HCFCs)
HCFC-141b, HCFC-124, HCFC-22, HCFC-142b
• Hydrofluorocarbons (HFCs)
HFC-23, HFC-32, HFC-125, HFC-134a,
HFC-143a, HFC-152a, HFC-227ea,
HFC-236fa, HFC-365mfc, HFC-245fa, HFC-
43-10mee, desflurane
• Perfluorocarbons (PFCs), etc
CF4, PFC-218, PFC-318, C4F10, C6F14, SF6,
SF5CF3
Global Warming
Kyoto Protocol
Halogenated Compounds in the Atmosphere
Ozone Depletion/Global Warming
Montreal Protocol

3. Halocarbons as Greenhouse Gases
in IPCC 5AR

4. Velders et al., Science (2012)
Halocarbons as Greenhouse Gases:
History and Future

5. NOAA/ESRL Network
Halocarbon Surface and Aircraft Sampling
AGAGE Network
Continuous in-situ Sampling
Global Measurements of Halocarbons

6. 2014 UNEP/WMO Ozone Assessment
The Montreal Protocol
Everything on Track

7. ~160 000 tons/year
Global box model
𝐵(𝑡)
𝑙𝑖𝑓𝑒𝑡𝑖𝑚𝑒
+
𝑑𝐵(𝑡)
𝑑(𝑡)
= emission
𝐵(𝑡): mass of F-134a in atmosphere
lifetime: 14 years
𝑑𝐵(𝑡)
𝑑(𝑡)
: rate of change
How to derive regional emissions?
Box-model approach for estimating global sources
The Kyoto-Protocol
Emission Estimation world-wide
coolant agent HFC-134a

8. Example: Combination of Measurements and Models:
The "unknown" European HFC-23 source

9. How to derive country-based emissions?

10. CO
COCO
CO
CO
CO
CO
CO
CO
F-134a
F-134a
F-134a
F-134a
F-134a
During stable conditions in summer well-mixed emissions from the
Swiss boundary layer are transported to Jungfraujoch (3850 m asl)
=
CO inventory
CO above background
emission of F-134a
F-134a above background
Top-Down Emission estimation for Switzerland

11. Annex 5.1 Independent verification of the National Swiss Inventory for F-gases
Switzerland’s Greenhouse Gas Inventory 2001-2014
Swiss Inventory:
8.5% annual loss car air conditioners:

12. NIR (UNFCCC) Annex 6: Independent verification of the National UK Inventory
UK’s Greenhouse Gas Inventory 1995-2014
-
1
2
3
4
5
6
7
Emissions(kt)
Mace Head measurements combined with the NAME model
measurement-based
1 site 4 sites
inventory
15% loss
A. Manning (MetOffice, UK)

13. Inversion
algorithm
Inverse Modelling for Inventory Support
A priori estimates of
surface flux
Constituent
observations
Simulated flux
sensitivities
High-Resolution Models Inventories
A posteriori estimates
of surface flux
Country total emissions
Measurements

14. HFC Inversion in the EU project INGOS
Four groups & inversion systems
Empa, Dominik Brunner (WP lead)
Empa2, Stephan Henne
NILU, Rona Thompson
UKMO, Tim Arnold / Alistair Manning
Three measurement sites
Jungfraujoch, Mace Head, Monte Cimone
A posteriori simulation of HFC-125 at Mace Head A posteriori HFC-125 emissions per country
Annual average sensitivity (footprint)

15. HFC Inversion in EU project INGOS
Brunner et al., in preparation

16. measurement-based
emissions
inventory-based
emissions

17. • Atmospheric measurements of halocarbons can be
used to provide real-world support of inventories used
in international agreements.
• The measurement-based approach is essential for
identifying gaps and for providing trust between
countries and different global regions.
• Measurements and methods for the measurement-
based emission estimation have to be performed in a
coordinated manner and have to be standardized.
Summary and Outlook