# Presentation: 279043

## Air Quality and Climate Connections

** **
**Air Quality and Climate Connections**

**Green and Environmental Systems **
**Regional and Urban Air Quality: Now and in the Future**
**New York Academy of Sciences, NY **
**February 28, 2007**

**Arlene M. Fiore**
**(arlene.fiore@noaa.gov)**

**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 (J****ülich)**** **

## The U.S. smog problem is spatially widespread, affecting >100 million people [U.S. EPA, 2004]

**4****th**** highest daily max 8-hr O****3**** ****>**** 84 ppbv**

## Air pollutants affect climate by absorbing or scattering radiation

**NMVOCs**
**CO  CH****4**

**NO****x**

**pollutant sources**

**+**

-  **O****3**

**+**

**OH**

**H****2****O**

**Aerosols interact with sunlight**
**“****direct” + “indirect” effects**
**composition matters!**

**Surface of the Earth**

**atmospheric cleanser**

## Radiative forcing of climate (1750 to present):Important contributions from air pollutants

**IPCC,***** 2007***

**Notes:**
Sulfate as main driver for “total aerosol”

##  50% 

**50% **
**anth.**
** ****NO****x**

** ****50% **
**anth.**
** ****CH****4**

**50% **
**anth.**
**VOC**

**CLIMATE: Radiative Forcing (W m****-2****)**

- Fiore* et al., GRL, *2002

**Double dividend of Methane Controls:**
**  ****Decreased greenhouse warming and improved air quality**

**Ozone precursors**

**Results from GEOS-Chem global tropospheric chemistry model (4****°****x5°)**

**Notes:**
GRAB #s from GRL TABLE in West et al 
Per ppb o3 change CH4 best for climate 

## OZONE

**0.2**

**0.1**

**0.0**

**-0.2**

**-0.1**

**OZONE**
**METHANE**

- +0.16 Net Forcing (W m-2)

- +0.08

- 0.00

- -0.08

**Reducing tropospheric ozone via methane controls decreases ****radiative forcing  (2030-2005)**

**Anthropogenic CH****4**** **
**Emissions (Tg yr****-1****)**

**Control scenarios reduce 2030 **
**emissions relative to CLE by:**
**A)****  ****-75 Tg   (18%) – cost-effective now**
** ****-125 Tg (29%) – possible with current technologies**
** ****-180 Tg (42%) – requires new technologies**

- West and Fiore, 2005; Fiore* et al*., in prep

**Radiative Forcing of Climate**

**A**

**B**

**C**

**CLE Baseline**

## How might future changes in aerosols affect climate?

**HISTORICAL and FUTURE SCENARIOS**

**CO****2**** concentrations **

**ppmv**

**Emissions of Short-lived **
**Gases and Aerosols (A1B)**

**1880 1920  1960 2000 2040  2080**

**NO****x**** (Tg N yr****-1****)**

**SO****2**** (Tg SO****2**** yr****-1****)**

**BC (Tg C yr****-1****)**

**25**
**20**
**15**
**10**
**  ****5**
**  ****0**

**250**
**200**
**150**
**100**
**  ****50**

**60**
**50**
**40**
**30**
**20**
**10**

- Horowitz, *JGR*, 2006

**Large uncertainty in future emission**
**trajectories for short-lived species**

**A1B**

- IPCC, 2001

## Up to 40% of U.S. warming in summer (2090s-2000s) from short-lived species

**From changing well-mixed **
**greenhouse gases +short-lived species**

**From changing only **
**short-lived species**

**Warming from increases in BC + decreases in sulfate;**
**depends critically on highly uncertain future emission trajectories**

**Results from GFDL Climate Model [Levy***** et al*****., 2006]**

**Change in Summer Temperature 2090s-2000s (****°****C)**

## Changes in global anthropogenic emissions affect regional air quality

**2030 A1**

**1995 Base case**

| IPCC 2030
Scenario | Anthrop. NOx emis.
Global            U.S. |  | Methane emis. |
| --- | --- | --- | --- |
| A1 | +80% | -20% | +30% |

- GEOS-Chem Model (4°x5°) [Fiore* et al., GRL*, 2002]

**Rising global emissions may offset U.S. efforts to reduce pollution**

**longer O****3**** season**** **

**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 O****3**** > 84 ppbv vs. daily max. temperature**

**Observed surface ozone over the U.S. ****correlates strongly with temperature**

**Lin***** et al*****., 2001**

**1980-1998 summertime**
**observations**

**Probability**

**0.5**
**0.4**
**0.3**
**0.2**
**0.1**
**0.0**

** ****62                71                80                89               98  (°F)**

**Temperature**

**New England**

**Southeast**

**Los Angeles**

**Notes:**
Above 305K, 20% probability of exceedance in NEngland

## How does climate affect air quality? 

##          Pollution build-up during 2003 European heatwave

- Carlos Ordóñez ordc@aero.obs-mip.fr Laboratoire d'Aérologie Toulouse, France

**CO and O****3 ****from airborne observations (MOZAIC)**

- Above Frankfurt (850 hPa; ~160 vertical profiles

- Contribution to GEMS, Integrated Project  of the 6th EC Framework Programme
- GEMS-GRG subproject coordinated by Martin Schultz (m.schultz@fz-juelich.de)

**         ****Pollution build-up during 2003 European heatwave**

**Stagnant high pressure system over Europe**
- (500 hPa geopotential anomaly relative to 1979-1995 for 2-14 August, NCEP)

**H**

## Observations during 2003 European heatwave show enhanced biogenic VOC concentrations

**Hogrefe *****et al*****., *****EM*****, 2005**

- 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*

**concentration (pptv)**

**temperature (****°****C)**

**BVOCs**

**= 95 ****°F**

**= 86 ****°F**

**= 77 ****°F**

##  Impacts on surface O3 from T-driven increases in reaction rates, humidity, and BVOC emissions 

**due to changes in climate**

**Climate-driven O****3**** increases may counteract air quality improvements achieved via local anthropogenic emission reductions**

**3 p.m. O****3**** 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]

**ppbv**

**ppbv**

## Changing climate may increase pollution events over the eastern U.S.

**Daily max 8-hr O****3**
**(5-year summer mean)**

**ppbv**

**Tracer of anthropogenic pollution (July-August)**

- Simulations using present-day emissions with future climates

- 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]

**Relative Frequency (%)**

**2045-2052 A1B**

**1995-2002**

**Increase in frequency and duration of pollution events**
**due to decrease in frequency of mid-latitude storms**

**Eastern U.S.**

## 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 O****3**** > 80 ppbv**
**(2090-2100 A1) – (1990-2000)****  **

- MOZART-2 global tropospheric chemistry model with meteorology from NCAR climate model [Murazaki and Hess, *J. Geophys. Res*., 2006]

- More inflow of clean air from Gulf of Mexico

**Less trans-Pacific transport**

**Increase in polluted **
**(high-NO****x****) regions**

## Air Quality and Climate Connections: Research Focal Points

** ****Costs and benefits of “win-win” (*****e.g.***** BC, CH****4****) 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)**