The Impact of Global Change on Air Quality

Transcription

1 The Impact of Global Change on Air Quality Photo image area measures 2 H x 6.93 W and can be masked by a collage strip of one, two or three images. The photo image area is located 3.19 from left and 3.81 from top of page. Each image used in collage should be reduced or cropped to a maximum of 2 high, stroked with a 1.5 pt white frame and positioned edge-to-edge with accompanying images. Darrell Winner, Ph.D. U.S. EPA; ORD/NCER/ASD winner.darrell@epa.gov July 15, 2009

2 Outline Potential impact of climate change on: Ozone Particulate matter Toxics Pollen

3 Acknowledgements Doug Grano, OAR/OAQPS Anne Grambsch ORD/NCEA Chris Weaver ORD/NCEA John Dawson, AAAS fellow ORD/NCER Ken Mitchell, EPA Region 4 Daniel Jacob, Harvard X.Z. Liang, Illinois State Water Survey

4 Climate Change Science The Intergovernmental Panel on Climate Change (IPCC) Established in 1988 by the World Meteorological Organization and the United Nations Environment Program to assess the risk of humaninduced climate change. The latest IPCC report is Climate Change 2007 ( Based on over 2500 scientific expert reviewers and 450 lead authors from over 130 countries. Evidence for warming of the climate system is unequivocal. The role of greenhouse gases is well understood and their increases are well identified. The net effect of human activities is now quantified and known to cause a warming at the Earth s surface.

5 Human Contribution to Climate Change Global atmospheric concentrations of greenhouse gases increased markedly as a result of human activities In 2005, the concentration of CO2 exceeded by far the natural range over the last 650,000 years 10,000 5,000 0 Time (before 2005) IPCC 9-07

6 Between 1970 and 2005, GHG Emissions Increased 70% IPCC 5-07

7 IPCC 9-07

8 Ranges of predicted surface warming IPCC 9-07

9 Climate Change vs (Ensemble of 20 GCMs from IPCC 4 th assessment report) Jacob and Winner, 2009

10 Changes in earth s energy balance Radiative forcing Measure of the cooling or warming (radiative) effect due to a change (forcing) in the climate system For example, an increase in the concentration of carbon dioxide has a warming effect The following chart indicates The relative importance of Greenhouse Gases Forcing from various factors over the last 250 years The uncertainties associated with these estimates

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12 Greenhouse radiative forcing of climate between 1750 and 2005 [IPCC, 2007] Referenced to forcing agent Referenced to emission Ozone radiative forcing: 0.35 W m -2 compare to 1.6 W m -2 for CO 2 but NO x emissions have net cooling effect, due to offsetting effects on methane and nitrate The best strategy to decrease ozone radiative forcing is to decrease methane emissions also decreases ozone background D. Jacob, Harvard

13 Impact of climate change on air quality - Ozone

14 Empirical evidence suggesting climate change could affect AQ O 3 episodes (mostly summer) are generally what we care about Right combination of meteorological conditions e.g., high temperature, clear skies, stagnant air with the right blend of precursor pollutants, e.g., NO x, VOCs Global climate change has the potential to affect both regional meteorology and regional emissions Example: Probability of max daily 8-hour O 3 exceeding 84 ppb as a function of max daily T Likely to see different degrees of change in different regions Lin et al. [2001]

15 Air Quality Assessment Framework Global Chemistry Modeling (Harvard, Carnegie Mellon, Illinois) Intercontinental Air Pollution (OAR) Global Change Scenarios (tech change, population growth, economic activity levels ) Global Air Quality Regional Boundary Conditions Global Emissions Regional Meteorology Global Meteorology Regional Change Scenarios Regional Emissions Climate Downscaling (PNNL, Illinois, WSU, Columbia, Harvard, Carnegie Mellon) Socio-economic scenarios (NCEA) Regional development (Georgia Tech, UC- Davis, RFF, UT-Austin, UW-Seattle, Illinois, Johns Hopkins, Columbia) Climate Effects of Aerosols (OAR) Regional Air Quality Technology Assessments with MARKAL (NRMRL) Air Quality Modeling (NERL, Harvard, Georgia Tech, Carnegie Mellon, Illinois, Berkeley, WSU, Harvard, Columbia, Johns Hopkins) Biogenics modeling (NERL, Forest Service, UC- Boulder, UNC, UT-Austin, UNH) Emissions Modeling (NRMRL, OAR, Illinois)

16 Consequences of Global Change for Air Quality EPA STAR grants exploring the effect of Climate, land use, technology, and demographic change on Ozone, particulate matter, and precursor emissions Modeling future impact of global changes on US air quality (6 grants, $5.4 million FY 02) Future anthropogenic air pollution emissions (2 grants, $1.5 million FY 03) Future biogenic air pollution emissions (4 grants, $2.8 million FY 03) Regional development, population trend, and technology change impacts on future air pollution emissions (8 grants, $4.9 million FY 04/05) Fire, climate, and air quality (3 grants, $2.2 million FY 06) Consequences of Global Change for Air Quality (10 grants, $9.0 million FY 07/08) Prequel - Consequences of interactions between human activities and a changing climate (3 relevant grants, $4.2 million FY 00)

17 Disproportionately large climate-induced changes for high-o 3 extremes 95 th Percentile MDA8 O 3 Shift in Typical Duration of > 84 ppb O 3 Episodes Mean MDA8 O 3 Hogrefe et al. [2004] Shift in the O 3 Distribution Nolte et al. [2008] Wu et al. [2008]

18 an EPA-STAR project (R and R833370) Daniel J. Jacob (P.I.) and Loretta J. Mickley, Harvard John H. Seinfeld, Caltech David Rind, NASA/GISS Joshua Fu, U. Tennessee David G. Streets, ANL Daewon Byun, U. Houston change in climate change in U.S. air quality change in pollutant emissions

19 IPCC scenarios and derived emissions greenhouse gases GISS GCM transient climate simulation ozone and PM precursors mercury met. input boundary conditions GEOS-Chem CTM global O 3 -PM-Hg simulation 2050 vs climate MM5 mesoscale dynamics simulation boundary conditions met. input CMAQ O 3 -PM-Hg simulation

20 2000 emissions: GEOS-Chem, including NEI 99 for United States % change, anthropogenic: SRES A1B scenario % change, natural: GISS/GEOS-Chem Global United States 2000 emissions % change, emissions % change, NO x, Tg N y -1 Anthropogenic % % Lightning Soils (natural) % +8% % +11% NMVOCs, Tg C y -1 Anthropogenic Biogenic % +23% % +23% CO, Tg y % 87-47% Methane, ppbv (+37%) results from EPA STAR grant R830959, Harvard Wu et al. [2008]

21 ozone, ppb (2000 emissions w/ 2050 climate) (2050 emissions & 2000 climate) (2050 emissions & climate) results from EPA STAR grant R830959, Harvard Wu et al. [2008]

22 Climate Change Penalty Harvard study suggests that climate change in the Northeast U.S. would necessitate a 50% NO x reduction to achieve the same O 3 goals as a 40% reduction today 2000 climate with NO x emissions reduced by 40% 2050 climate - 60% NO x 2050 climate - 50% NO x Wu et al. [2008]

23 Leibensperger et al. (2008), ACP Decreasing trend in mid-latitude cyclone frequency in US ( ) Significant for NCEP/NCAR reanalysis (-0.15 yr -1 ) & NOAA maps Not significant for NCEP/DOE reanalysis We find that if mid-latitude cyclone frequency had not declined, the northeastern US would have been largely compliant with the ozone air quality standard by 2001

24 Interannual Variability Observed average number of summer days in the Northeast U.S. with 8-hour O 3 > 84 ppb From EPA NERL study, simulated increases in O 3 in 2050 are of same order as present-day year-to-year variability in some regions. Nolte et al. [2008]

25 Extension of O 3 Season? EPA NERL Simulation Results: Change in MDA8 O 3 from present to 2050s for September-October Nolte et al. [2008]

26 Modeling Future Changes in the Mid-Latitude Storm Tracks Harvard Carnegie Mellon MDA8 O 3 change by 2050s Mickley et al. [2004]

27 Modeling Isoprene Nitrate Chemistry Harvard Carnegie Mellon MDA8 O 3 change by 2050s Key: Is isoprene nitrate a terminal or temporary sink for NO x in model chemistry?

28 Impact of climate change on air quality Particulate matter

29 Major predicted climate effects on PM Warming climate affects particulate matter More water vapor plus changing weather patterns Increasing rainout events (decreasing PM in some regions) Increasing drought (increasing PM in some regions) Increase in number and length of stagnation events Changing biogenic emissions Changing some particles to the gaseous state Drought-related increases in dust emissions. Longer wildfire seasons and larger fires. The net impact is unclear.

30 Carnegie Mellon modeling setup Models GISS II GCM/CTM MM5 PMCAMx 5 present and s climate (IPCC A2) Present-day PM/precursor emissions Climate / emissions scenario Meteorology Meteorology GCM/CTM (GISS II ) Regional met model (MM5) Chemical boundary conditions Regional CTM (PMCAMx) Regionalscale air quality

31 July PM 2.5 Future Present, A2 climate change, present day emissions Mix of species/met effects: Largely sulfate Stagnation Mixing height Precipitation? Temperature? PM 2.5 (μg m -3 ) Land-cell average = +2.2 μg m -3 Dawson et al. (2009)

32 Important processes not well-represented Organics? Wildfires? Feedback effects? Global transport?

33 Insights into the effect of climate change on air quality Effect of climate change Ozone PM (aerosol) Stagnation Temperature??? Mixing depth Precipitation Cloud cover = =? Humidity = (relative) Jacob and Winner, AE 2009

34 Impact of climate change on air quality - Toxics Courtesy of Sustaining the Environment and Resources for Canadians

35 Climate Impacts on Toxics-General Higher temperatures indicate greater evaporative emissions Mobile sources evaporative emissions, including benzene Stationary sources evaporative emissions, including solvents Mitigation measures in response to climate change may alter air toxic emissions from a variety of sources Reformulation of vehicle fuels E85 will increase two major carcinogens, acetaldehyde and formaldehyde while slightly reducing another, butadiene, and reducing a fourth, benzene. (E85 subject of STAR grant) Less fossil fuel combustion as other fuels are developed More geothermal production, waste incineration, and woodstove use?

36 Example.Climate Impacts on Mercury Mercury chemistry and emission rates are affected by temperature Increased rates of re-emission of mercury from land and ocean are associated with increased temperatures. Temperature increases in the North Atlantic are projected to increase rates of mercury methylation in fish and marine mammals, thus increasing human exposure via consumption. Mercury in biomass (plants and litter) and soil carbon pools are affected by climate change and in turn can affect mercury uptake, sequestration and emission. Plant growth may be initially enhanced by increased CO 2 levels. Increases in wildfires may release more biomass/soil mercury to the atmosphere. [IPCC 2007 WGII Adaptation] [Obrist STAR grant] [Jacob STAR grant]

37 Mercury-Climate Change Research Several EPA grants are underway to explore Hg chemistry and transport as a function of climate and emissions changes through the use of both models and observational datasets Climate change can potentially impact a number of atmospheric processes that help determine the fate of Hg heterogeneous oxidation of gas-phase Hg dry deposition of elemental reactive gas-phase and particulate Hg Hg chemistry in the presence of fog, clouds, and photochemical smog. Focus on present and future Hg distribution for the U.S. as a whole, as well as for particular regions (e.g., Great Lakes, Florida) Work aimed at improving Hg chemistry in linked climate and air quality modeling systems by incorporating additional reactions and refining existing representations

38 Impact of climate change on air quality - Pollen

39 Climate impacts on pollen Warming and climate extremes are likely to increase respiratory illness, including exposure to pollen (IPCC 2007) Climate change has caused an earlier onset of the spring pollen season in the Northern Hemisphere. It is unclear whether the allergenic content of these pollen types has changed (pollen content remaining the same or increasing would imply increased exposure) A doubling of the atmospheric CO2 concentration stimulated ragweed-pollen production by over 50%.

40 Using air quality results in health impact studies Combine air quality results with tools used to calculate health impacts of air pollution (e.g. Benmap) Pat Kinney (Columbia) and his team have led the way (you will hear from him this afternoon) Brand new results from Ted Russell (Georgia Tech) and his group: Potential Impact of Climate Change on Air Pollution-Related Human Health Effects (2009) E. Tagaris, K.-J. Liao, A. J. DeLucia, L. Deck, P. Amar, A. G. Russell, Environmental Science & Technology 43 (13), Results suggest that climate change driven air quality-related health effects will be adversely affected in more than 2/3 of the continental U.S. Changes in health effects induced by PM2.5 dominate compared to those caused by ozone. PM2.5-induced premature mortality is about 15 times higher than that due to ozone. Nationally the analysis suggests approximately 4000 additional annual premature deaths due to climate change impacts on PM2.5 vs 300 due to climate change-induced ozone changes. High uncertainty Expect more studies soon