Reducing the Potential for Black Carbon to Impact the Arctic

Transcription

1 Reducing the Potential for Black Carbon to Impact the Arctic Jennifer L. DeWinter, Sean M. Raffuse, Steven G. Brown, and Kenneth J. Craig Sonoma Technology, Inc. Petaluma, CA for Transportation for Sustainability: Sustainable Transportation for Climate Change Washington, DC May 7, 2015 STI-6260

2 Introduction 2 Overview Since 1990, vehicle improvements in the U.S. (retrofits, fuel standards) have led to reduced emissions from cars and trucks This resulted in important health benefits by reducing exposure to PM 2.5, NO x, and diesel particulate matter (DPM), which includes black carbon (BC) The changes also have important climate-related co-benefits

3 Introduction 3 What is Black Carbon? Black carbon (BC) is a component of fine particle mass (PM 2.5 ) Image courtesy of the U.S. EPA

4 Introduction 4 What is Black Carbon? Formed during incomplete combustion of fossil fuels, biofuels, and biomass Domestic/ residential 4% Energy/power 7% Industry 1% Other 1% Open biomass 35% On-road gasoline 4% Commercial marine 7% Locomotive 7% Nonroad gasoline 2% Tire/brake wear <1% Aircraft <1% Nonroad diesel 34% Transport 52% On-road diesel 46% U.S. BC emissions in U.S. BC emissions from mobile sources in

5 Introduction 5 BC and Health PM 2.5 is a criteria pollutant associated with negative respiratory and cardiovascular effects, and premature death BC particles (0.1-1 µm in size) represent a fraction of primary and secondary PM 2.5 (relative amount depends on emissions source) 1 The EPA lists DPM as an air toxic and southern California health studies indicate that it is the greatest contributor to cancer risk 2 BC is a large fraction of DPM (~30-50%) 2,3,4

6 Introduction 6 BC and Climate BC is strongly light absorbing and is a short-lived climate forcer (days to weeks) 1,5 Atmospheric BC reduces sunlight and causes warming BC deposits on snow and ice reduce surface albedo, which accelerates warming (EPA, 2008) 6 (EPA, 2012) 1

7 Introduction 7 Research Motivation When, where, how much, and from what sources BC is emitted all have implications for impacts on the Arctic and human health. Our study asks: What meteorological patterns are conducive to transporting emissions to the Arctic? How do location, timing, and emissions source height affect transport? Need to understand these factors to develop and assess sector-specific emissions reductions strategies

8 8 Methods (1) 30-year climatological trajectory analysis (Jan Dec. 2009) not to scale not to scale

9 9 Methods (2) Forward trajectories modeled from 1,926 hypothetical source locations across the United States Trajectories initialized every six hours Trajectories initialized at seven vertical levels Modeled forward for 10 days Source location in United States Air parcel location after 72 hours forward from source Modeled using the NOAA Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model with two gridded meteorology data sets (NARR and NCAR/NCEP) that were nested for our domain

10 10 Methods (3) Typical transport pathway from source locations to the Arctic

11 11 Results (1) Fraction of days when a trajectory reached the Arctic during

12 12 Results (2) Transport potential varies by emissions source height At or below 1,000 meters AGL At or below 500 meters AGL

13 13 Results (3) Transport potential varies by duration of time for transport 2 or fewer days 7 or fewer days 10 or fewer days

14 Implications 14 Mobile Source Emissions and Transport Potential Emissions from locations where transport is greater may be more likely to impact the Arctic Mobile source emissions from U.S. EPA NEI,

15 Implications 15 Future Impacts PM 2.5 exhaust emissions decrease sharply, especially from 2010 to 2020 Reductions in BC expected Locations of reductions are important for reducing Arctic impacts CA statewide emissions modeled with MOVES 8

16 16 Conclusions We determined the potential for transport of BC from the U.S. to the Arctic Transport potential varies by latitude, by day, seasonally, and annually Robust climatological data set available for assessing potential impacts of emissions BC emissions from transportation expected to decrease in the U.S. BC emissions reductions have important climate co-benefits

17 17 References (1) U.S. Environmental Protection Agency (2012) Report to Congress on black carbon. Report prepared by the Office of Air Quality Planning and Standards, Office of Atmospheric Programs, Office of Radiation and Indoor Air, Office of Research and Development, and Office of Transportation and Air Quality, Research Triangle Park, NC, EPA-450/R , March. Available at (2) South Coast Air Quality Management District (2014) Multiple Air Toxics Exposure Study: MATES IV draft report. Findings presented at the SCAQMD Governing Board Meeting, October 3. Available at (3) Fruin S.A., Winer A.M., and Rodes C.E. (2004) Black carbon concentrations in California vehicles and estimation of in-vehicle diesel exhaust particulate matter exposures. Atmos. Environ., 38(25), , August. (4) Schauer J.J. (2003) Evaluation of elemental carbon as a marker for diesel particulate matter. Journal of Exposure Analysis and Environmental Epidemiology, 13(6), , November.

18 18 References (5) Bond T.C., Doherty S.J., Fahey D.W., Forster P.M., Berntsen T., DeAngelo B.J., Flanner M.G., Ghan S., Kärcher B., Koch D., Kinne S., Kondo Y., Quinn P.K., Sarofim M.C., Schultz M.G., Schulz M., Venkataraman C., Zhang H., Zhang S., Bellouin N., Guttikunda S.K., Hopke P.K., Jacobson M.Z., Kaiser J.W., Klimont Z., Lohmann U., Schwarz J.P., Shindell D., Storelvmo T., Warren S.G., and Zender C.S. (2013) Bounding the role of black carbon in the climate system: a scientific assessment. Journal of Geophysical Research: Atmospheres, 118(11), , doi: /jgrd Available at (6) U.S. Environmental Protection Agency (2008) National air quality status and trends through Report prepared by the Office of Air Quality Planning and Standards, Air Quality Assessment Division, Research Triangle Park, NC, EPA-454/R , November. Available at (7) U.S. Environmental Protection Agency (2015) National Emissions Inventory (NEI) air pollutant emissions trends data website. Mobile source emissions from Available at (8) Bai S., Du Y., and Reid S. (2015) Contributions of tire wear and brake wear to particulate matter emissions inventories for on-road mobile sources. Presented at the 2015 International Emission Inventory Conference, San Diego, CA, April 12-16, by Song Bai, Sonoma Technology, Inc., Petaluma, CA. STI-6133.

19 sonomatech.com 19 Contact Jennifer DeWinter Atmospheric Scientist

20 Supplemental 20 Supplemental Material

21 Supplemental 21 Annual Variability Results Transport potential varies by year

22 Supplemental 22 Seasonal Variability Results Transport potential varies by season (greatest in winter and fall) Winter Spring Summer Fall

23 Supplemental 23 BC from Motor Vehicles: International Perspective Source: Wang et al. (2012) Global Emission of Black Carbon from Motor Vehicles from 1960 to Environ. Sci. Technol. 2012, 46,

24 Supplemental 24 BC from Motor Vehicles: International Perspective Source: Wang et al. (2012) Global Emission of Black Carbon from Motor Vehicles from 1960 to Environ. Sci. Technol. 2012, 46,

25 Supplemental 25 Europe/Asia Results Percent of days on which a trajectory from a given area reached the Arctic during from Europe/Asia