Air Quality and Climate Connections Arlene M. Fiore ([email protected]) Acknowledgments: Larry Horowitz, Chip Levy, Dan Schwarzkopf (GFDL) Vaishali Naik, Jason West (Princeton U), Allison Steiner.
Download ReportTranscript Air Quality and Climate Connections Arlene M. Fiore ([email protected]) Acknowledgments: Larry Horowitz, Chip Levy, Dan Schwarzkopf (GFDL) Vaishali Naik, Jason West (Princeton U), Allison Steiner.
Air Quality and Climate Connections Arlene M. Fiore ([email protected]) Acknowledgments: Larry Horowitz, Chip Levy, Dan Schwarzkopf (GFDL) Vaishali Naik, Jason West (Princeton U), Allison Steiner (U Michigan) Carlos Ordóñez (Laboratoire d'Aérologie), Martin Schulz (Jülich) Green and Environmental Systems Regional and Urban Air Quality: Now and in the Future New York Academy of Sciences, NY February 28, 2007 The U.S. smog problem is spatially widespread, affecting >100 million people [U.S. EPA, 2004] OZONE Nonattainment Areas (2001-2003 data) 4th highest daily max 8-hr O3 > 84 ppbv U.S. EPA, 2006 AEROSOLS (particulate matter) Annual Average PM2.5 in 2003 Exceeds standard U.S. EPA, 2004 Air pollutants affect climate by absorbing or scattering radiation Greenhouse gases absorb infrared radiation T Aerosols interact with sunlight “direct” + “indirect” effects composition matters! Smaller droplet size clouds last longer less precipitation O3 H2O more cloud droplets NMVOCs + OH + NOx CO CH4 T atmospheric cleanser Black carbon sulfates (soot) pollutant sources Surface of the Earth T Radiative forcing of climate (1750 to present): Important contributions from air pollutants IPCC, 2007 Double dividend of Methane Controls: Decreased greenhouse warming and improved air quality Results from GEOS-Chem global tropospheric chemistry model (4°x5°) CLIMATE: Radiative Forcing (W m-2) NOx OH AIR QUALITY: Number of U.S. summer grid-square days with O3 > 80 ppbv CH4 50% anth. VOC 50% 50% anth. anth. NOx CH4 Ozone precursors 1995 50% 50% (base) anth. anth. VOC CH4 50% anth. NOx Fiore et al., GRL, 2002 Reducing tropospheric ozone via methane controls decreases radiative forcing (2030-2005) Anthropogenic CH4 Emissions (Tg yr-1) 0.2 CLE Baseline 0.1 A Radiative Forcing of Climate +0.16 Net Forcing (W m-2) +0.08 0.00 -0.08 0.0 B C -0.1 -0.2 OZONE METHANE CLE A B C Control scenarios reduce 2030 emissions relative to CLE by: A) -75 Tg (18%) – cost-effective now B) -125 Tg (29%) – possible with current technologies C) -180 Tg (42%) – requires new technologies West and Fiore, 2005; Fiore et al., in prep How might future changes in aerosols affect climate? HISTORICAL and FUTURE SCENARIOS Emissions of Short-lived CO2 concentrations Gases and Aerosols (A1B) 60 60 50 40 30 20 10 50 NOx Emissions (T g N/yr) NOx (Tg N yr-1) 40 30 A1B 20 ppmv 10 IPCC, 2001 0 250 200 150 100 50 250 SO2 Emissions (T g SO2/yr) SO2 (Tg SO2 yr-1) 200 Pollution controls 150 100 50 0 BC (Tg C yr-1) 1880 1920 1960 2000 2040 2080 2100 2080 2060 2040 2020 2000 1980 1960 1940 1920 1900 Horowitz, JGR, 2006 1880 Large uncertainty in future emission trajectories for short-lived species BC Emissions (Tg C/yr) 1860 25 20 20 15 15 10 10 55 00 25 Up to 40% of U.S. warming in summer (2090s-2000s) from short-lived species Results from GFDL Climate Model [Levy et al., 2006] From changing well-mixed greenhouse gases +short-lived species From changing only short-lived species Change in Summer Temperature 2090s-2000s (°C) Warming from increases in BC + decreases in sulfate; depends critically on highly uncertain future emission trajectories Changes in global anthropogenic emissions affect regional air quality 1995 Base case 2030 A1 IPCC 2030 Scenario A1 Anthrop. NOx emis. Global U.S. +80% -20% Methane emis. +30% longer O3 season GEOS-Chem Model (4°x5°) [Fiore et al., GRL, 2002] Rising global emissions may offset U.S. efforts to reduce pollution How will changes in climate influence regional air quality? Observed surface ozone over the U.S. correlates strongly with temperature Probability of daily max 8-h O3 > 84 ppbv vs. daily max. temperature 0.5 1980-1998 summertime observations Probability 0.4 New England 0.3 Los Angeles 0.2 0.1 Southeast 0.0 62 71 80 Temperature 89 98 (°F) Lin et al., 2001 How does climate affect air quality? (1) Meteorology (stagnation vs. well-ventilated boundary layer) Degree of mixing strong mixing Boundary layer depth pollutant sources (2) Emissions (biogenic depend strongly on temperature; fires) VOCs Increase with T, drought? T (3) Chemistry responds to changes in temperature, humidity T generally faster reaction rates NMVOCs NO O3 + x + OH CO, CH4 H2O Pollution build-up during 2003 European heatwave CO and O3 from airborne observations (MOZAIC) Above Frankfurt (850 hPa; ~160 vertical profiles Ozone HEATWAVE Stagnant high pressure system over Europe (500 hPa geopotential anomaly relative to 1979-1995 for 2-14 August, NCEP) H CO Ventilation (low-pressure system) Carlos Ordóñez [email protected] Laboratoire d'Aérologie Toulouse, France Contribution to GEMS, Integrated Project of the 6th EC Framework Programme GEMS-GRG subproject coordinated by Martin Schultz ([email protected]) GRG Observations during 2003 European heatwave show enhanced biogenic VOC concentrations concentration (pptv) temperature (°C) = 95 °F = 86 °F = 77 °F BVOCs Measurements from August 2003 Tropospheric Organic Chemistry Experiment (TORCH) in Essex, UK, during hottest conditions ever observed in the UK c/o Dr. Alistair Lewis, University of York, UK Hogrefe et al., EM, 2005 Impacts on surface O3 from T-driven increases in reaction rates, humidity, and BVOC emissions 3 p.m. O3 change (ppbv) in 3-day O3 episode with CMAQ model (4x4 km2), applying T change from 2xCO2 climate (changes in meteorology not considered) [Steiner et al., JGR, 2006] due to changes in climate normalized to a +1°C 5 4 ppbv 3 O3 response depends on local chemistry (available NOx) 2 1 0 ppbv reaction rates humidity BVOC combined Climate-driven O3 increases may counteract air quality improvements achieved via local anthropogenic emission reductions Changing climate may increase pollution events over the eastern U.S. Simulations using present-day emissions with future climates Relative Frequency (%) Daily max 8-hr O3 (5-year summer mean) Tracer of anthropogenic pollution (July-August) 2045-2052 A1B Eastern U.S. 1995-2002 ppbv Regional CMAQ model (36 km2) with GISS boundary conditions Hogrefe et al., JGR 2004; EM 2005 in GISS global model (4°x5°) [Mickley et al., GRL, 2004] Increase in frequency and duration of pollution events due to decrease in frequency of mid-latitude storms Surface O3 change under future climate varies: increases in polluted regions; decreases in “background” Mean annual change in number of days where daily max 8-hr O3 > 80 ppbv (2090-2100 A1) – (1990-2000) Less trans-Pacific transport Increase in polluted (high-NOx) regions More inflow of clean air from Gulf of Mexico MOZART-2 global tropospheric chemistry model with meteorology from NCAR climate model [Murazaki and Hess, J. Geophys. Res., 2006] Air Quality and Climate Connections: Research Focal Points Costs and benefits of “win-win” (e.g. BC, CH4) and “win-lose” (e.g. sulfate) strategies for joint mitigation of air pollution and climate forcing Aerosol feedbacks on climate, globally and regionally Response of biogenic emissions and fires to changes in climate and land-use Evolution of air quality with global change (climate + anthropogenic and “natural” emissions)