Transcript New gases (presentation by Mr. Forster)

School of Earth and Environment
FACULTY OF ENVIRONMENT
Professor Piers Forster, University of Leeds, UK
Technical Briefing to AWG-KP on
including others gases
Tuesday 2 June 2009, UNFCC Bonn
Talk covers
•GWPs used in the Kyoto Protocol
•Updates to Kyoto Protocol GWPs
•GWPs of non-Kyoto Protocol gases
•GWPs for indirect/short-lived effects
•Atmospheric measurements
•Emission inventories
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 2
100 year GWPs used in Kyoto
protocol and updates
Gas
KP (SAR)
AR4
Changes since SAR
CO2
1
1
CH4
21
25
Absolute GWP CO2 reduced -> all
non CO2 GWPs increased by 27%
unless science improved
indirect effects, radiative efficiency
N2O
310
298
Iife-time and radiative efficiency
HFCs (e.g. HFC134a)
1,300
1,430
radiative efficiency
PFCs (e.g. PFC-14)
6,500
7,390
radiative efficiency
SF6
23,900
22,800
life-time, radiative efficiency
Revised Table 2.14 Errata,1 Dec 2008, from IPCC WG1 AR4, Chapter 2,
Forster et al., 2007
ipcc-wg1.ucar.edu/wg1/Report/AR4WG1_Errata_2008-12-01.pdf
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 3
GWPs quantified in AR4 that were not in
Kyoto Protocol or SAR Table
• 20 Ozone Depleting Substances - covered by Montréal protocol
• 6 additional HFCs (152, 161, 227ea, 236cb, 236ea,
245fa,365mfc)
• 1 PFC (PFC-9-1-18): uncertain lifetime, medical applications, minor?
•7 other compounds with short lifetimes (e.g. Halon-1201, Chloroform, DME)
•3 Perfluorinated compounds
• NF3 - electronics industry, see next page
• SF5CF3 likely related to SF6 emissions, very powerful GHG, long lived
•
c-C3F6, ozone depleting substance replacement
• 31 Fluorinated ethers: solvents, potential refrigerants, currently expensive
• 1 Perfluoropolyether (PFPMIE): heat transfer fluid
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 4
Progress since AR4
•Sulfuryl fluoride (SO2F2) A fumigant
GWP uncertain but may be large
Dillon, T., A. Horowitz & J. Crowley, The atmospheric chemistry of sulfuryl fluoride,
SO2F2, Atmos. Chem. Phys., 8, 1547-1557, 2008
•Nitrogen trifluoride (NF3), technology industry, flat panel TVs
Study finds a reduced lifetime for NF3 of 550 years which would lead
to a smaller 100 yr GWP (16,800 rather than 17,200)
Emission confirmed by atmospheric measurements to be 620 tons or
16% of production (industry estimate was 2%)
Weiss, R. F., J. Mühle, P. K. Salameh, and C. M. Harth (2008), Nitrogen trifluoride in the
global atmosphere, Geophys. Res. Lett., 35, L20821, doi:10.1029/2008GL035913.
Prather, M. J., and J. Hsu (2008), NF3, the greenhouse gas missing from Kyoto,
Geophys. Res. Lett., 35, L12810, doi:10.1029/2008GL034542.
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 5
Indirect/Short-lived GWPs
AR4 quantified indirect GWPs for methane, carbon monoxide, nitrogen
oxides, non- methane volatile organic compounds, hydrogen – only
methane indirect effects included in main GWP table
Generally 100 year GWPs are less than 10, except for maybe nitrogen
oxides from aircraft
GWPs for short-lived species vary with location and timing of emissions:
any metric would be uncertain
GWPs not quantified in AR4 for emissions affecting non GHGs (e.g.
aerosols, condensation trails from aircraft)
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 6
Emission estimates
Emissions evaluated
using a combination of
techniques
Complexity/methodology
varies with country/sector
Crudest methods rely on
scaling economic
indicators
Right: atmospheric
measurements of year to year
changes (100-yr GWP used to
infer GtC units)
Figure 2.7, IPCC WG1 chapter
2 , Forster et al, 2007
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 7
Summary
GWP for many non-KP gases are included in AR4 table - see Errata for
complete table
• Many of these gases not necessarily expected to be important for climate
change but some may become important (e.g. NF3)
Changes in GWPs since SAR largely related to reduced radiative
efficiency of CO2
GWPs well established for major species but uncertainties can be large for
minor species
Uncertainties and methodological considerations with use of GWPs for
short-lived and indirect climate change drivers
2 June 2009, Bonn
Prof Piers Forster, Technical Briefing
to AWG on KP
Slide 8