1. Ref: D. Fahey, adapted from IPCC 4th Assessment, Summary for Policymakers, Feb. 2, 2007 WHAT ARE THE MAJOR HUMAN & NATURAL ACTIVITIES FORCING CLIMATE CHANGE IN THE INDUSTRIAL ERA (1750-2005)? 1.6 W m -2 x 5.1 x 10 14 m 2 = 8.16 x 10 14 W = 816 TW (about 52 times current global energy consumption)! RON PRINN, MIT-FEN LUNCHEON TALK, 10/14/08

2. Global Cycles of Greenhouse Gases are studied using Measurements & Global Circulation models 28-level 1.8 o x1.8 o Model for Atmospheric Transport & Chemistry (MATCH) uses NCEP meteorology AGAGE measures 45 gases 20-36 times per day at globally distributed stations dating back to 1978 How well do we understand Greenhouse Gas (GHG) Cycles?

3. AGAGE NETWORK STATIONS Hateruma (Japan) Mt. Cimone (Italy) Jungfraujoch (Switzerland) Ny-Alesund (Norway)

4. AGAGE INSTRUMENTATION 1. Medusa GC-MS 2. GC-Multi-detector 3. Calibration 1. 3. 2.

5. MONTREAL PROTOCOL GASES & THEIR REPLACEMENTS

6. Radiative Forcing from Carbon Dioxide and other Greenhouse gases CO 2 CH 4 N2ON2O CFCs others

7. TRENDS IN METHANE: WHY DO THEY VARY INTERANNUALLY AND WHY HAVE THEY DECELERATED IN RECENT YEARS? QUASI-STEADY STATE: Emissions(CH 4 ) ~ k[OH].Content(CH 4) ? Ref: IPCC 4th Assessment, Summary for Policymakers, Feb. 2, 2007 AGAGE NOAA

8. High-Frequency (13: AGAGE, NOAA, etc.) and Flask (41 comprehensive & 32 more intermittent: NOAA, CSIRO, etc.) monthly mean observations between 1996-2001 Interannually varying transport (NOAA/NCEP) used in 3D MATCH model (T62, 1.8 o x1.8 o, 28 levels, 1000-2.9mb) to create the CH 4 response of each site to monthly pulses from individual regional processes (sensitivity H(t) matrix) Kalman Filter used to solve for: (a) 7 Seasonally-varying processes as monthly varying fluxes (b) 2 Pseudo-steady processes as constant fluxes using annually repeating time/space varying MATCH model OH tuned to AGAGE CH 3 CCl 3 observations METHANE INVERSE STUDIES USING 3D MATCH MODEL (Chen & Prinn, 2005, 2006)

9. El Nino winds La Nina winds AGAGE observations versus MATCH model at Samoa MIRROR PLOT MATCH Simulates Effects of ENSO Transport on CH 4 Ref: Chen & Prinn, J.G.R., 2005

10. SUMMARY: AVERAGE SEASONAL CYCLES (SELECTED AND ALL DATA SETS) CAPTURES EXPECTED SEASONAL CYCLES (RICE PEAKS EARLIER) Reference High Freq. All Best Ref: Chen & Prinn, J.G.R., 2006

11. Summary: Interannual variability (Monthly Anomalies) 32-33 Tg yr -1 Total Emission increase in 1998 with 8-17 Tg yr-1 due to Rice regions Northern/Tropical Wetland and Rice Region Emissions dominate the total variability Fluxes in Tg yr -1 Northern Wetlands Tropical Wetlands Inversion 5-108.3-9.9 Bottom-up* 1213 BUT Boreal Fires in Siberia may have also contributed to our deduced strong Northern wetlands increase *wetland model driven by 1998 record temperature and large precipitation anomalies (Dlugokencky et al. (2001)) 1998 wetland Flux Anomalies

12. Summary: 5-year averages _ (literature) (1) ENERGY RELATED EMISSIONS SMALLER (RUSSIAN GAS LEAKS?) COMPARED TO PREVIOUS ESTIMATES: (2) RICE RELATED EMISSIONS LARGER (PROXIMAL WETLANDS OR TROPICAL ECOSYSTEMS?)

13. METHANE IS RISING AGAIN, BUT WHY? (TRENDS AT AGAGE & CSIRO STATIONS) (Rigby et al, 2008)

14. RESULTS FOR EMISSION ANOMALIES FROM INVERSIONS (Rigby et al, 2008)

15. The hydroxyl free radical (OH) is the major oxidizing chemical in the global atmosphere It annually removes about 3.7 billion metric tons of trace gases (CO, CH 4, higher hydrocarbons, hydro- halocarbons, NO x, SO x, etc.) from the atmosphere.. Are the levels of this dominant cleansing chemical changing? A decrease is dangerous! With a lifetime of only about 1 second it is possible to measure locally, but not possible to measure directly at regional to global scales. Use AGAGE measurements of the industrial chemical CH 3 CCl 3, whose major sink is OH, to indirectly estimate large scale OH variations. It annually removes about 3.7 billion metric tons of trace gases (CO, CH 4, higher hydrocarbons, hydro- halocarbons, NO x, SO x, etc.) from the atmosphere.. Are the levels of this dominant cleansing chemical changing? A decrease is dangerous! With a lifetime of only about 1 second it is possible to measure locally, but not possible to measure directly at regional to global scales. Use AGAGE measurements of the industrial chemical CH 3 CCl 3, whose major sink is OH, to indirectly estimate large scale OH variations.

16. [OH] (10 5 radicals cm -3 ) Ref: Update of Prinn, Huang et al, G.R.L., 2005 The inferred OH minima generally coincide with strong El Nino’s and/or massive global wildfires (updated from Prinn, Huang, et al, G.R.L.,2005). The 2006-2007 drop is therefore unexpected. Global weighted average OH inferred from AGAGE CH 3 CCl 3

17. 12.335(U) / 12.835(G) Experimental Atmospheric Chemistry (Fall 2008) Logistics: Lectures:Tuesdays (usually), 12:30-2:30pm, Room 54-1510 Lab Periods: Thursdays (usually), 12:30-2:30pm, Room 54-1811 4 Field Trips: Sun: 9/7, Fri: 10/10, Sat: 11/1, Sat: 11/15 Attendance at lectures, labs and especially field trips is mandatory. Instructors: Ronald G. Prinn, 54-1312, rprinn@mit.edu Laura Meredith, 54-1320, predawn@mit.edu Kat Potter, 54-1414, kep@mit.edu Grading: 10% - Participation 20% - Topic 1 - CO 2 & Climate 20% - Topic 2 - CFCs & Ozone Layer 20% - Topic 3 - Air Pollution & Health 30% - Topic 4 - Tropospheric Photochemistry - [20% - Lab Report, 10% - Presentation] Each student will focus on a chosen aspect of tropospheric photochemistry for their topic 4 lab report and presentation. A list of possible subjects will be provided mid-semester and student selections are due on Nov. 17 th. Credit: 2-2-8 Undergraduate or Graduate Credits Stellar website: http://stellar.mit.edu/S/course/12/fa08/12.335/rprinn@mit.edupredawn@mit.edukep@mit.eduhttp://stellar.mit.edu/S/course/12/fa08/12.335/ 12.335(U) / 12.835(G) Experimental Atmospheric Chemistry (Fall 2008) Logistics: Lectures:Tuesdays (usually), 12:30-2:30pm, Room 54-1510 Lab Periods: Thursdays (usually), 12:30-2:30pm, Room 54-1811 4 Field Trips: Sun: 9/7, Fri: 10/10, Sat: 11/1, Sat: 11/15 Attendance at lectures, labs and especially field trips is mandatory. Instructors: Ronald G. Prinn, 54-1312, rprinn@mit.edu Laura Meredith, 54-1320, predawn@mit.edu Kat Potter, 54-1414, kep@mit.edu Grading: 10% - Participation 20% - Topic 1 - CO 2 & Climate 20% - Topic 2 - CFCs & Ozone Layer 20% - Topic 3 - Air Pollution & Health 30% - Topic 4 - Tropospheric Photochemistry - [20% - Lab Report, 10% - Presentation] Each student will focus on a chosen aspect of tropospheric photochemistry for their topic 4 lab report and presentation. A list of possible subjects will be provided mid-semester and student selections are due on Nov. 17 th. Credit: 2-2-8 Undergraduate or Graduate Credits Stellar website: http://stellar.mit.edu/S/course/12/fa08/12.335/rprinn@mit.edupredawn@mit.edukep@mit.eduhttp://stellar.mit.edu/S/course/12/fa08/12.335/