International Transport of Air Pollutants (ITAP)

1. International Transport of Air Pollutants (ITAP) Terry J. Keating, Ph.D. Office of Air & Radiation U.S. Environmental Protection Agency

2. Animation of CO Concentrations Observed by NASA’s MOPITT/TERRA

3. What have we learned about International Transport? While most air quality problems are due to local or regional sources, the U.S. is both an importer and exporter of air pollution.

4. Transboundary Flows with Canada & Mexico What do we know? Transboundary flow can be important during exceedances of the NAAQS, as well as during exceedances of Canadian & Mexican policy objectives. Major emissions sources have been located along both borders, and new sources continue to be built. SO2 Ann Emiss, BRAVO

5. What do we know? Some of the most dramatic examples of international transport are not anthropogenic. On July 8, 2002, forest fires in Quebec created a smoke plume that blanketed the U.S. East Coast. [NASA MODIS image]

6. Imports from Central America What do we know? Flows from Central America carry smoke, as well as other pollutants, including pesticides. Pesticide use per acre in Central America exceeds the US by a factor of 10. In May 1998, fires in Central America create a smoke plume across the central U.S. GOES-8 Satellite Image, CIMSS Univ of Wisconsin

7. Imports from Africa What do we know? Dust, metals, and other pollutants are transported from North Africa across the Atlantic to the Caribbean and the Southeastern U.S. Saharan Dust over Miami = 10 – 100 mg/m3 24 hr PM NAAQS = 65 mg/m3 PM 2.5 150 mg/m3 PM 10 [Prospero 1999] Pathogens in Saharan Dust have been linked to coral decline in the Caribbean. [Shinn et al 2000]

8. Exports to Europe What do we know? The U.S. exports ozone precursors, mercury, and other pollutants to the North Atlantic. The impact on attainment of European policy objectives may be significant. Days predicted to exceed the EU ozone standard that would not exceed the standard in the absence of North American emissions. [Li et al. , 2001]

9. What do we know? Imports to Alaska & Arctic Mercury, POPs, and other pollutants are carried into the Arctic, by circulation patterns and “global distillation.” Arctic Air Mass InSummerandWinter Air Transport Pathways [Crane & Galasso, 1999]

10. What do we know? Emissions distribution Contribution of different continents Global mercury emissions inventory for 1995 (provided by AMAP) Mercury Deposition ~40% of all Hg deposition to the lower 48 states comes from emission sources outside the U.S. or from U.S. emissions that have been transported across international boundaries From Travnikov, EMEP MSC-E [EPA, 1997]

11. Imports from Asia What do we know? Dust from Chinese Deserts, fossil fuel emissions, and other pollutants travel across the Pacific and impact the Western U.S. [Aerosol Index, NASA TOMS] Emissions in Asia are expected to grow with further economic development, offsetting emissions decreases in the United States. World Energy Use [EIA, 2002]

12. What do we know? Imports from Asia Simulated increase in mean U.S. surface ozone (ppbv) from tripling of Asian emissions (1985 to 2015). Future ozone impacts could be enough to offset the benefits of 25% decrease in U.S. emissions! Jacob et al. [1999]

13. Implications for the U.S.? Standard Local Regional Ozone concentration Hemispheric background Historical Future Future (alternate view) The Tightening Vise From Keating, West, and Farrell (in press)

14. Implications for the U.S.? NOx VOC SO2 CO What will future emissions be? IPCC-SRES global emission trends vs. national medium-term projections From Markus Amann, IIASA

15. Implications for the U.S.? The International Challenge For EPA to achieve it’s own strategic goals and objectives, we need to: • develop a better understanding of the impact of other countries on the US • develop a better understanding of the impact of the US on other countries • help reduce these pollution sources through cost-effective appropriate technology, recognizing linkages between pollution problems

16. The End

17. What are we doing? Improving Our Understanding • EPA ITAP Working Group

18. What are we doing? Improving Our Understanding • EPA ITAP Working Group • International and National Scientific Workshops Including: Trans-Pacific Transport, Seattle, July 2000 Trans-Atlantic Transport, New York, June 2001 Hemispheric Transport, Germany, Oct 2002

19. What are we doing? Improving Our Understanding • EPA ITAP Working Group • International and National Scientific Workshops • OIA-ORD Speciated Mercury Monitoring Including: Cheeka Peak, Washington Barrow, Alaska Mauna Loa, Hawaii

20. What are we doing? Improving Our Understanding • EPA ITAP Working Group • International and National Scientific Workshops • OIA & ORD Speciated Mercury Monitoring • OAR/OAQPS Collaboration with NASA

21. What are we doing? Improving Our Understanding • EPA ITAP Working Group • International and National Scientific Workshops • OIA & ORD Speciated Mercury Monitoring • OAR/OAQPS Collaboration with NASA • OAR/OAQPS Intercontinental transport and Climatic effects of Air Pollutants (ICAP) Project

22. What are we doing? Intercontinental Transport & Climatic Effects • Global Modeling of Ozone and Related Oxidants • Jacob, Harvard Univ • Global and Regional Climate Impact of Aerosols • Jacobson, Stanford Univ • Emission Inventories for Climate-Forcing Pollutants • Streets, Argonne National Lab • Modeling of Trans-Pacific Transport • Hanna, Carolina Environmental Programs