Grantee Research Project Results
2008 Progress Report: Effects of Future Emissions and a Changed Climate on Urban Air Quality
EPA Grant Number: R833371Title: Effects of Future Emissions and a Changed Climate on Urban Air Quality
Investigators: Jacobson, Mark Z. , Streets, David G.
Institution: Stanford University , Argonne National Laboratory
EPA Project Officer: Chung, Serena
Project Period: February 1, 2007 through January 31, 2011 (Extended to January 31, 2012)
Project Period Covered by this Report: February 1, 2008 through January 31,2009
Project Amount: $899,984
RFA: Consequences of Global Change For Air Quality (2006) RFA Text | Recipients Lists
Research Category: Climate Change , Air
Objective:
This is a four-year project to study the effects of changes in emissions on climate and the resulting feedback of climate change to air quality. We are examining the effects of emission changes resulting from standard IPCC-SRES future emission scenarios and from different fuel types.Progress Summary:
To date, several studies relevant to the project goals have either been published/accepted for publication (5) or submitted for publication: (1) a study examining the effect of carbon dioxide in isolation on air quality and human health in the U.S., (2) a study examining the effect on global climate and stratospheric ozone of converting the world’s fossil-fuel onroad vehicles (FFOV) to hydrogen fuel cell vehicles (HFCV), where the hydrogen is produced by wind-powered electrolysis, (3) a study examining the short-term effects of irrigation and albedo differences due to agriculture on California and Los Angeles air pollution and climate, (4) a study on the effect of future A1B and B1 emission scenarios on the emissions of natural gases and particles, global climate, and global air quality, and (5) a study examining the temperature dependence of ethanol versus gasoline effects on air quality using a large explicit chemical mechanism. These papers are described below.
One paper that was published quantifies the link between carbon dioxide alone and air pollution health problems (Jacobson, 2008a). Previous studies of the effects of global warming on air pollution did not isolate carbon dioxide’s effect alone or quantify the global-scale carbon dioxide-induced temperature and water vapor change effects on both regional-scale particle and gas aerosol pollution and the resulting health effects. The conclusion of this study was that each degree Celsius rise in temperature in the U.S. may lead to an additional 1000 air-pollutionrelated deaths per year (with a range of uncertainty provided in the paper). About 300 of these additional deaths per year occur in California, which has about 12% of the U.S. population, indicating a disproportionate share of deaths in California. The study involved the globalthrough-urban simulation of climate and its feedback to air pollution.
Another study examined the effect on global climate and stratospheric ozone of converting the world’s fossil-fuel onroad vehicles (FFOV) to hydrogen fuel cell vehicles (HFCV), where the hydrogen is produced by wind-powered electrolysis (Jacobson, 2008b). It was found that such a conversion should reduce gas and aerosol emissions. Such reductions should reduce stratospheric and tropospheric aerosol and cloud acidification and surface area and 2 increase precipitation/wet removal, all of which feed back to increasing stratospheric ozone. Over the long term, a conversion may cool the troposphere and warm the stratosphere, speeding ozone-layer recovery further. Wind-HFCV should simultaneously reduce tropospheric ozone and replace similar amounts of H2 (at a 3% leakage rate) and H2O emitted by FFOV. Thus, wind-HFCV (and similarly renewable-powered battery electric vehicles) should also reduce stratospheric ozone and decrease tropospheric pollution.
Jacobson (2008c) studied the short-term effects of irrigation and albedo differences due to agriculture on California and Los Angeles air pollution and climate. High-resolution irrigation, land use, soil, albedo, and emission data were applied at the subgrid scale in the nested global-through-urban GATOR-GCMOM model to examine these issues following a comparison of baseline model results with data. It was found that, in August, irrigation alone increased soil moisture, increasing nighttime but decreasing daytime ground temperatures more, causing a net ground cooling in California and Los Angeles. Agriculture was calculated to increase the albedo of the northern Central Valley but decrease that of the southern valley more relative to nonagricultural land today, offsetting part of the cooling due to irrigation alone. The spatial maximum day-night average August cooling in the Central Valley due to irrigation plus albedo differences from agriculture was 0.9 K at 30 m height and 2.3 K at the ground, in range of an historic 0.74-2.4 K cooling at 2 m attributed to heavily-irrigated agriculture in an independent data study. When averaged over all model cells containing >0% irrigation, irrigation alone and irrigation plus albedo differences decreased day-night average 2-m temperatures by 0.44 K and 0.16 K, respectively, indicating greater local than regional effects of agriculture. In the Central Valley, irrigation increased the relative humidity, cloud water, and precipitation, shifting aerosol and soluble gas mass to clouds and rain. In the valley and Los Angeles, agriculture stabilized air, decreasing wind speeds and turbulence, increasing pollution in the absence of rain. Thus, when enhancing clouds and precipitation, agriculture decreased pollution; otherwise, agriculture increased pollution. Agriculture in parts of the polluted eastern Los Angeles basin increased fine particulate matter by ~2% and ozone by ~0.1%. All results were robust to a change in the simulation date, although further evaluation is needed to better quantify effects of agriculture on climate and air quality.
Jacobson and Streets (2009) examined the effect of future emission changes on natural emissions, global climate, and air quality. Speciated sector- and region-specific 2030 emission factors were developed to produce gas and particle emission inventories that followed Special Report on Emission Scenarios (SRES) A1B and B1 emission trajectories. Current and future climate model simulations were run in which anthropogenic emission changes affected climate, which fed back to natural emissions from lightning (NO, NO2, HONO, HNO3, N2O, H2O2, HO2, CO), soils (dust, bacteria, NO, N2O, H2, CH4, H2S, DMS, OCS, CS2), the ocean (bacteria, sea spray, DMS, N2O, H2, CH4), and vegetation (pollen, spores, isoprene, monoterpenes, methanol, other VOCs) and photosynthesis/respiration. New methods were derived to calculate lightning flash rates as a function of size-resolved collisions and other physical principles and pollen, spore, and bacteria emissions. Although the B1 scenario was “cleaner” than the A1B scenario, global warming increased more in the B1 scenario because much A1B warming was masked by additional reflective aerosol particles. Thus, neither scenario is entirely beneficial from a climate and health perspective, and the best control measure is to reduce warming gases and warming/cooling particles together. Lightning emissions declined by ~3% in the B1 scenario and 3 by ~12% in the A1B scenario as the number of ice crystals, thus charge-separating bounceoffs, decreased. Net primary production increased by ~2% in both scenarios. Emissions of isoprene and monoterpenes increased by ~1% in the A1B scenario and 4-5% in the B1 scenario. Nearsurface ozone increased by ~14% in the A1B scenario and by ~4% in the B1 scenario, reducing ambient isoprene in the latter case. Gases from soils increased in both scenarios due to higher temperatures. Near-surface PM2.5 mass increased by ~2% in the A1B scenario and decreased by ~2% in the B1 scenario. The resulting 1.4% higher aerosol optical depths in the A1B scenario decreased ocean wind speeds and thus ocean sea spray and bacteria emissions; ~5% lower AODs in the B1 scenario had the opposite effect.
Another paper being written up for this project is Ginnebaugh et al. (2009), which examines the effect of temperature dependence on ethanol versus gasoline on air pollution using an explicit 14,500-reaction chemical mechanism. This paper evaluated the chemical mechanism against smog chamber data then performed box-model sensitivity tests to isolate the effects of temperature on atmospheric gas-phase chemistry of gasoline versus ethanol emissions.
With respect to emissions, we have now generated new future emission factors for three scenarios. The speciated, sector-specific, and region-of-the-world-specific emission factors between 2000 and 2050 for the A1B and B1 emission scenarios and for an additional A1B scenario in which fossil-fuel passenger vehicles were replaced by hydrogen fuel cell vehicles (90% penetration in developed countries and 45% penetration in developing countries), assuming the hydrogen is produced by steam-reforming of natural gas. These emission factors were developed using information from the GREET model and accounted for well-to-wheels emissions. Emission factors were developed for six separate source categories: stationary fuel combustion—electric boilers, stationary fuel combustion—industrial and commercial boilers, industrial processes—non-combustion, storage and transport—evaporative emissions, on-road vehicles, and off-road vehicles. These factors were then applied to gridded 2000 emission data to provide gridded emissions for 2050.
Future Activities:
For the next period of this project, we will run simulations for 2050 under the A1B future emission scenario and the 2050 A1B scenario modified for hydrogen fuel cell vehicles, where the hydrogen is produced by steam-reforming of natural gas. This scenario assumes a 90% penetration of hydrogen passenger vehicles in developed countries and a 45% penetration in developing countries. We will also prepare 2050 emission scenarios for an electric vehicle case and for one more case. We will also finish work on a paper examining the effect of 5 locally-emitted carbon dioxide on local air pollution and continue to refine the papers submitted or in preparation for this project.Journal Articles on this Report : 4 Displayed | Download in RIS Format
| Other project views: | All 66 publications | 23 publications in selected types | All 23 journal articles |
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Jacobson MZ. Short-term effects of agriculture on air pollution and climate in California. Journal of Geophysical Research 2008;113(D23):D23101 (18 pp.). |
R833371 (2008) R833371 (2009) R833371 (2010) R833371 (Final) |
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Jacobson MZ. On the causal link between carbon dioxide and air pollution mortality. Geophysical Research Letters 2008;35(3):L03809 (5 pp.) |
R833371 (2007) R833371 (2008) R833371 (2009) R833371 (2010) R833371 (Final) |
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Jacobson MZ. Effects of wind-powered hydrogen fuel cell vehicles on stratospheric ozone and global climate. Geophysical Research Letters 2008;35(19):L19803 (5 pp.). |
R833371 (2008) R833371 (2009) R833371 (2010) R833371 (Final) |
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Ketefian GS, Jacobson MZ. A mass, energy, vorticity, and potential enstrophy conserving lateral fluid-land boundary scheme for the shallow water equations. Journal of Computational Physics 2009;228(1):1-32. |
R833371 (2008) R833371 (2009) R833371 (2010) R833371 (Final) |
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Supplemental Keywords:
Global warming and health, future emissions, alternative-energy vehicles, numerical modeling., RFA, Scientific Discipline, Air, climate change, Air Pollution Effects, Environmental Monitoring, Ecological Risk Assessment, Atmosphere, air quality modeling, Baysian analysis, emissions impact, climate models, alternative fuel, atmospheric modelsRelevant Websites:
www.stanford.edu/group/efmh/jacobsonProgress and Final Reports:
Original AbstractThe perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.