Grantee Research Project Results
Final 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 Amount: $899,984
RFA: Consequences of Global Change For Air Quality (2006) RFA Text | Recipients Lists
Research Category: Climate Change , Air
Objective:
Summary/Accomplishments (Outputs/Outcomes):
This report summarizes the cumulative progress during this project. Eighteen papers relevant to the project goals were published or are still in review. These include (1) 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 (Jacobson and Streets, 2009), (2) a study examining the effects of ambient and emitted carbon dioxide on air quality and human health in the U.S. (Jacobson 2008a), (3) a study examining the effects of local CO2 domes on air pollution health (Jacobson, 2010a), (4) 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 (Jacobson, 2008b), (5) a study examining the short-term effects of irrigation and albedo differences due to agriculture on California and Los Angeles air pollution and climate (Jacobson, 2008c), (6) a study describing the development of a fluid-land boundary treatment scheme for inviscid shallow water flows that conserves the domain-summed mass, energy, vorticity, and potential enstrophy in multiply-connected domains, i.e. in domains encompassing arbitrarily-shaped islands (Ketefian and Jacobson, 2009), (7) a study describing an expansion of the fluid-land boundary treatment from stair step to continuous boundary conditions (Ketefian and Jacobson, 2011), (8) a study examining the temperature dependence of ethanol versus gasoline emissions on air quality using a 13,600-reaction chemical mechanism (Ginnebaugh et al., 2010), (9) a study evaluating a 13,600-reaction chemical mechanism in a 3-D nested model (Jacobson and Ginnebaugh, 2010), (10) a study extending the near-explicit gas mechanism to a gas plus aqueous mechanism and its analysis and timing for 3-D application (Ginnebaugh and Jacobson, 2012), (11) a study examining the effects on global and Arctic climate and air pollution health of fossil-fuel soot versus biofuel soot and gases, and methane (Jacobson, 2010b), (12) a study isolating properties of black carbon, tar balls, and soil dust in clouds and aerosols and identifying Cloud Absorption Effects I and II, (13) a study discussing a new numerical method for solving drop breakup following collision/coalescence in rain-forming clouds (Jacobson, 2011), (14) a data analysis study examining boomerang curves from satellite data (the increase in cloud optical depth (COD) with increasing aerosol optical depth (AOD) at low AOD followed by the decrease in COD with increasing AOD at high AOD, (Ten Hoeve et al., 2011), (15) an extension of that study to demonstrate the ability of the GATOR-GCMOM model to predict satellite-derived boomerang curves (Ten Hoeve et al., 2012a), (16) a study of the biomass burning trends over the Amazon over a several year period (Ten Hoeve et al., 2012b), (17) a study of the impacts on worldwide human health of the Fukushima Daiichi nuclear accident (Ten Hoeve and Jacobson, 2012), and (18) a study of the effects of urban surfaces and white roofs on global and regional climate (Jacobson and Ten Hoeve, 2012). These papers are described below.
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 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 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-pollution-related 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 global-through-urban simulation of climate and its feedback to air pollution.
Jacobson (2010a) performed a followup study examining the effects of local emissions of CO2 on the formation of CO2 domes over cities and the resulting effects of such domes on local air quality and health. The study found, through data-evaluated numerical modeling with telescoping domains from the globe to the U.S., California, and Los Angeles, that local CO2 emissions in isolation may increase local ozone and particulate matter. Although health impacts of such changes are uncertain, they are of concern, and it was estimated that that local CO2 emissions may increase premature mortality by 50-100 and 300-1000/yr in California and the U.S., respectively. As such, reducing locally-emitted CO2 may reduce local air pollution mortality even if CO2 in adjacent regions is not controlled. If correct, this result contradicts the basis for air pollution regulations worldwide, none of which considers controlling local CO2 based on its local health impacts. It also suggests that a “cap and trade” policy should consider the location of CO2 emissions, as the underlying assumption of the policy is incorrect.
Jacobson (2008b) 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. The study 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 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. Because this study examined the effect of a different vehicle technology on global climate and air pollution, it was directly relevant to this project.
Another paper published as part of this project examined the short-term effects of irrigation and albedo differences due to agriculture on California and Los Angeles air pollution and climate (Jacobson, 2008c). 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.
Ketefian and Jacobson (2009) developed a fluid-land boundary treatment scheme for inviscid shallow water flows that conserves the domain-summed mass, energy, vorticity, and potential enstrophy in multiply-connected domains, i.e. in domains encompassing arbitrarily shaped islands. The boundary scheme was derived from a previous scheme that conserves all four domain-summed quantities only in singly-connected periodic domains, i.e. periodic domains without islands. It consists of a method for including land in the model along with evolution equations for the vorticity and extrapolation formulas for the depth at fluid-land boundaries. Proofs of mass, energy, vorticity, and potential enstrophy conservation are given. Numerical simulations are carried out demonstrating the conservation properties of the boundary scheme for inviscid flows and comparing its performance with that of four alternative boundary schemes. The first of these uses extrapolation and finite-differencing to calculate the vorticity at boundaries; the second enforces the free-slip boundary condition; the third enforces the super-slip condition; and the fourth enforces the no-slip condition. The comparison shows that the new scheme is the only one of the five that conserves all four domain-summed quantities, and it is the only one that simultaneously prevents a spurious energy cascade to the smallest resolved scales and maintains the correct flow orientation with respect to an external forcing.
Ketefian and Jacobson (2011) developed a numerical scheme for treating fluid–land boundaries in inviscid shallow water flows. The method approximates boundary profiles with piecewise linear segments (shaved cells) while conserving the domain-summed mass, energy, vorticity, and potential enstrophy. The new scheme is a generalization of a previous scheme that also conserves these quantities but used stairsteps to approximate boundary profiles. Numerical simulations were carried out demonstrating the conservation properties and accuracy of the piecewise linear boundary scheme (the PLS) for inviscid flow and comparing its performance with the stairstep scheme (the STS). It was found that while both schemes conserved all four domain-summed quantities, the PLS generated depth and velocity fields that were one-half to one order more accurate than those generated by the STS, and it generated vorticity and potential vorticity fields that were at least as accurate as those generated by the STS and often more accurate. The higher accuracy of the PLS is due to its ability to generate smoother flow fields near boundaries of arbitrary shape.
Another important aspect of this project was the implementation, evaluation, and application of a largely-explicit chemical mechanism. Two papers were published on this topic (Ginnebaugh et al., 2010 and Jacobson and Ginnebaugh, 2010). These papers are discussed briefly, in turn.
Ginnebaugh et al. (2010) combined the Master Chemical Mechanism (MCM, version 3.1, LEEDS University) with the SMVGEAR II chemical ordinary differential solver to provide the speed necessary to simulate complex chemistry in 0-D or 3-D. The MCM has over 13,500 organic reactions and 4600 species. SMVGEAR II is a sparse-matrix Gear solver that reduces the computation time significantly while maintaining any specified accuracy. The chemical mechanism was tested for its accuracy in comparison with smog chamber data. A box model version was then combined with species-resolved tailpipe emissions data for E85 (15% gasoline, 85% ethanol fuel blend) and gasoline vehicles to compare the impact of each on nitrogen oxides, organic gases, and ozone as a function of ambient temperature and background concentrations, using Los Angeles in 2020 as a base case. Two different emissions data sets were used: one was a compilation of exhaust and evaporative data taken near 24 C and the other from exhaust data taken at 7 C. Diurnal effects were examined over two-day scenarios. It was found that, accounting for chemistry and dilution alone, the average ozone concentrations through the range of temperatures tested were higher with E85 than with gasoline by 7 part per billion volume (ppbv) at higher temperatures (summer conditions) to 39 ppbv at low temperatures and low sunlight (winter conditions) for an area with a high nitrogen oxide (NOx) to non-methane organic gas (NMOG) ratio. The results suggest that E85's effect on health through ozone formation becomes increasingly more significant relative to gasoline at colder temperatures due to the change in exhaust emission composition at lower temperatures. Acetaldehyde and formaldehyde concentrations were also much higher with E85 at cold temperatures, which is a concern because both are considered to be carcinogens. These results could have implications for wintertime use of E85. Peroxyacetyl nitrate (PAN), another air pollutant of concern, increased with E85 as well. The sensitivity of the results to box size, initial background concentrations, background emissions, and water vapor were also examined.
Until this project, gas photochemistry had not been simulated beyond a few hundred reactions in a 3-D atmospheric model. In Jacobson and Ginnebaugh (2010), 4675 gases and 13,626 tropospheric and stratospheric reactions were implemented into the 3-D GATOR5 GCMOM climate-pollution model, and model results were compared with data and with results from a condensed 152-gas/297-reaction mechanism when the model was nested at increasing resolution from the globe to California to Los Angeles. Gases included C1-C12 organic degradation products and H-, O-, N-, Cl-, Br-, Fl-, and S-containing inorganics. Organic reactions were from the Master Chemical Mechanism. Photolysis coefficients for 2644 photoprocesses and heating rates for 1909 photolyzing gases were solved with an online radiative code in each grid cell using quantum yield/cross section data over 86 UV/visible wavelengths. Spatial/temporal emissions of >110 gases were derived from the 2005 U.S. National Emission Inventory. The condensed mechanism was a modified Carbon-Bond IV (MCBIV). Three-day simulation results indicate that the more-explicit mechanism reduced the O3 gross error against data versus the MCBIV error against data by only ~2 percentage points (from 28.3% to 26.5%) and NO2 and HCHO by ~6 percentage points in Los Angeles. While more-explicit photochemistry improved results, the condensed mechanism was not the main source of ozone error. The more explicit mechanism, which treated absorptive heating by more photolyzing gases, also resulted in a slightly different magnitude of feedbacks to meteorological variables and back to gases themselves, than did the less-explicit mechanism. The computer time for all processes in GATOR-GCMOM with the more-explicit mechanism (solved with SMVGEAR II in all domains) was only ~3.7 times that with the MCBIV despite the factors of 31 and 46 increases in numbers of species and reactions, respectively.
Subsequently, Ginnebaugh and Jacobson (2012) combined the MCM with an extensive aqueous-phase chemistry mechanism in SMVGEAR II with the ultimate goal of studying the impact of ethanol versus gasoline chemistry in gases, aerosol particles, and clouds together. The combined mechanisms were found to be sufficiently fast for use in a 3-D model due to the sparse-matrix and other techniques in SMVGEAR II. Results for the ethanol versus gasoline experiment are not available yet.
Next, a study was carried out to examine the short-term (~15 year) effects of controlling
fossil-fuel soot (FS) [black carbon (BC), primary organic matter (POM), and S(IV) (H2SO4(aq), HSO4-, and SO42-)], solid-biofuel soot and gases (BSG) (BC, POM, S(IV), K+, Na+, Ca2+, Mg2+,NH4+, NO3-, Cl- and several dozen gases, including CO2 and CH4), and methane on global and Arctic temperatures, cloudiness, precipitation, and atmospheric composition (Jacobson, 2010b). Climate response simulations were run with GATOR-GCMOM, accounting for both microphysical (indirect) and radiative effects of aerosols on clouds and precipitation. The model treated discrete size-resolved aging and internal-mixing of aerosol soot, discrete size-resolved evolution of clouds/precipitation from externally- and internally-mixed aerosol particles, and soot absorption in aerosols, clouds/precipitation, and snow/sea ice. Eliminating FS, FS+BSG
(FSBSG), and CH4 in isolation were found to reduce global surface air temperatures by a statistically significant 0.3-0.5 K, 0.4-0.7 K, and 0.2-0.4 K, respectively, averaged over 15 y. As net global warming (0.7-0.8 K) is due mostly to gross pollutant warming from fossil-fuel greenhouse gases (2-2.4 K), and FSBSG (0.4-0.7 K) offset by cooling due to non-FSBSG aerosol particles (-1.7 to -2.3 K), removing FS and FSBSG may reduce 13-16% and 17-23%, respectively, of gross warming to date. Reducing FS, FSBSG, CH4 in isolation may reduce warming above the Arctic Circle by up to ~1.2 K, ~1.7 K, and ~0.9 K, respectively. Both FS and BSG contribute to warming, but FS is a stronger contributor per unit mass emission. However, BSG may cause eight times more mortality than FS. The global e-folding lifetime of emitted BC (from all fossil sources) against internal mixing by coagulation was ~3 hours, similar to data, and that of all BC against dry plus wet removal was ~4.5 days. About 90% of emitted FS BC mass was lost to internal mixing by coagulation; ~7% to wet removal, ~3% to dry removal, and a residual remaining airborne. Of all emitted- plus internally-mixed BC, ~92% was wet removed and ~8% dry removed, with a residual remaining airborne. The 20- and 100 year surface temperature response per unit continuous emissions (STRE) (similar to global warming potentials – GWPs) of BC in FS were 4500-7200 and 2900-4600, respectively; those of BC in BSG were 2100-4000 and 1060-2020, respectively; and those of CH4 were 52-92 and 29-63, respectively. Thus, FSBSG may be the second-leading cause of warming after CO2. Controlling FS and BSG may be a faster method of reducing Arctic ice loss and global warming than other options, including controlling CH4 or CO2, although all controls are needed.
In an effort to analyze the results of Jacobson (2010b) in more detail, a process analysis study was performed to examine optical properties of black carbon (BC), tar balls (TB), and soil dust (SD) in aerosols and clouds (Jacobson, 2012). This study illustrated in detail Cloud Absorption Effects I and II, which were defined in the paper as the effects on cloud heating of absorbing inclusions in hydrometeor particles and of absorbing aerosol particles interstitially between hydrometeor particles at their actual relative humidity (RH), respectively. The globally and annually-averaged modeled 550-nm aerosol mass absorption coefficient (AMAC) of externally-mixed BC was found to be 6.72 (6.3-7.3) m2/g, within the laboratory range (6.3-8.7 m2/g). The global AMAC of internally-mixed (IM) BC was 16.2 (13.9-18.2) m2/g, less than the measured maximum at 100% RH (23 m2/g). The resulting AMAC amplification factor due to internal mixing was 2.41 (2-2.9), with highest values in high RH regions. The global 650-nm hydrometeor mass absorption coefficient (HMAC) due to BC inclusions was 17.7 (10.6-19) m2/g, ~9.3% higher than that of the IM-AMAC. The 650-nm HMACs of TBs and SD were half and 1/190th, respectively, that of BC. Modeled aerosol absorption optical depths were consistent with data. In column tests, BC inclusions in low and mid clouds (CAE I) gave column-integrated BC heating rates ~200% and 235%, respectively, those of interstitial BC at the actual cloud RH (CAE II), which itself gave heating rates ~120% and ~130%, respectively, those of interstitial BC at the clear-sky RH. Globally, cloud optical depth increased then decreased with increasing aerosol optical depth, consistent with boomerang curves from satellite studies. Thus, CAEs, which are largely ignored, were hypothesized to heat clouds significantly.
Jacobson (2011) developed a new volume- and volume-concentration-conserving, positive-definite, unconditionally-stable iterative numerical scheme for solving temporary cloud/raindrop coalescence followed by breakup and coupled it with an existing non-iterative, volume- and volume-concentration-conserving collision/coalescence (coagulation) scheme. The breakup scheme alone compares nearly exactly with a constant-kernel analytical solution at a 300-s time step (Figure 4). The combined coagulation/breakup schemes are stable and conservative, regardless of the time step and number of size bins, and convergent with higher temporal and size resolution. The schemes were designed with these characteristics in mind for use in long-term global or regional simulations. The use of 30 geometrically-spaced size bins and a time step of 60 s provides a good compromise between obtaining sufficient accuracy (relative to a much higher resolution result) and speed although solutions at 600 s time step and 30 bins are stable and conservative and take 1/8th the computer time. The combined coagulation/breakup schemes were implemented into the nested GATOR-GCMOM global-urban climate/weather/air pollution model. Coagulation was solved over liquid, ice, and graupel distributions and breakup simultaneously over the liquid distribution. Each distribution included 30 size bins and 16 chemical components per bin. Timing tests demonstrate the feasibility of the scheme in long-term global simulations.
Ten Hoeve et al. (2011) used satellite data to examine the impact of aerosols on clouds during the Amazonian biomass burning season in Brazil. They found that cloud optical depth (COD) increases with increasing aerosol optical depth (AOD) until an AOD of ~0.25, due to the first indirect effect. At higher values of AOD, COD decreased with increasing AOD most likely to cloud absorption of solar radiation by black carbon and other absorbing aerosol particle constituents (cloud absorption effects and semi-direct effects). This finding is important, since almost all models assumed an increasing linear relationship between AOD and COD, whereas in reality, this does not occur. The study also found that AOD-COD relationships should be stratified by column water vapor in order to separate out differences in meteorology that might contribute to the relationships.
These results were solidified further in Ten Hoeve et al. (2012a), who used the GATOR-GCMOM model to match well the satellite data, thereby demonstrating that the reduction in cloud optical depth on the right side of the boomerang curve was caused by absorbing aerosol particles. Meanwhile, Ten Hoeve et al. (2012b) isolated trends in biomass burning and drivers of those trends during a several year period in the Amazon. Ten Hoeve and Jacobson (2012) studied the impacts on worldwide exposure and health due to the Fukushima Daiichi nuclear accident.
Finally, Jacobson and Ten Hoeve (2012) examined the effects of urban surfaces and white roofs on global and regional climate. Land use, vegetation, albedo, and soil-type data were combined in GATOR-GCMOM, accounting for roofs and roads at near their actual resolution. Urban landcover was modeled over 20 years to increase gross global warming (warming before cooling due to aerosols and albedo change are accounted for) by 0.06-0.11 K and population-weighted warming by 0.16-0.31 K, based on two simulations under different conditions. As such, the urban heat island (UHI) effect was estimated to contribute to 2-4% of gross global warming, although the uncertainty range is likely larger than the model range presented, and more verification is needed. This was the first estimate of the UHI effect derived from a global model while considering both UHI local heating and large-scale feedbacks. Previous data estimates of the global UHI, which considered the effect of urban areas but did not treat feedbacks or isolate temperature changes due to urban surfaces from other causes of urban temperature change, implying a smaller UHI effect but of similar order. White roofs change surface albedo and affect energy demand. A worldwide conversion to white roofs, accounting for their albedo effect only, was calculated to cool population-weighted temperatures by ~0.02 K but to warm the Earth overall by ~0.07 K. White-roof local cooling may also affect energy use, thus emissions, a factor not accounted for here. As such, conclusions here regarding white roofs apply only to the assumptions made.
Conclusions:
This project allowed for the improvement and application of numerical models to study several important topics related to the effects of future emissions and a changed climate on urban air quality. Several studies examined the effects of proposed fuels (e.g., ethanol, hydrogen, nuclear power) on air pollution, human health, catastrophic risk, and/or climate. Others resulted in the development of future emission inventories and an examination of those inventories on air quality and global climate. Additional studies quantified the impacts of carbon dioxide on air pollution through its feedbacks to temperatures and water vapor. Yet, others resulted in improved numerical modeling tools and a better understanding of the radiative impacts of pollutants on clouds. Another set of studies examined the effects of urban surfaces, proposed white roofs, and agriculture on climate and air quality. A final set of studies examined the trends in biomass burning and the effects of its emissions on clouds, precipitation, and pollution. These studies, taken as a whole, have advanced our capabilities and knowledge in the area of the risk of air pollutants, their impacts on climate, and the resulting feedbacks of climate change to pollution and will be useful for more analyses in the future.
Some of the major policy-relevant results of this research were as follows:
- The demonstration by cause and effect that carbon dioxide, in isolation from other emissions, increases air pollution mortality locally, both due to carbon dioxide domes forming over cities (Jacobson, 2010) and global buildup of carbon dioxide (Jacobson, 2008a), was one of the scientific bases for granting the Waiver of Clean Air Act Preemption to the State of California by the U.S. EPA in 2009 (http://www.stanford.edu/group/efmh/jacobson/EPAhearing.html).
- The quantification of the effects of fossil fuel and biofuel black carbon on Arctic and global climate and human health (Jacobson, 2010b) was part of the scientific basis for European Parliament Resolution B7-0474/2011 (September 14, 2011) calling for black carbon emission controls on climate grounds.
- The study of urban surface and white roofs on climate (Jacobson and Ten Hoeve, 2012) confirmed through modeling for the first time that urban surfaces account for only a small portion of observed global warming. The paper also raised a caution about unintended consequences of white roofs, in that although they cool surfaces locally, their large-scale use may cause global warming.
- Modeling and satellite data analysis were used to show that cloud optical depth first increases then decreases with increasing aerosol optical depth over biomass burning regions; thus, indirect effects are cancelled by cloud absorption effects and semidirect effects as aerosol optical depth increases (Ten Hoeve et al., 2012a, 2011). This result contradicts the contention that aerosol indirect effects dominate the effects of aerosols on clouds.
- Black carbon in clouds were found to increase heating more as inclusions in cloud drops and interstitially between cloud drops than in the clear sky (Jacobson, 2012). As such, all models to date have underestimated the effects of black carbon on clouds.
- Ginnebaugh et al. (2010) and (2012) found that ethanol enhances air pollution over gasoline more significantly at low temperature than at room temperature, even in the presence of clouds. The low-temperature impact of ethanol has not been considered in any legislation to date.
- A future fleet of hydrogen fuel cell vehicles was found not to negatively impact human health, climate, or the ozone layer (Jacobson, 2008b). As such, there is little risk of largescale environmental impact of such a fleet.
- The Fukushima-Daiichi nuclear disaster was found to cause thousands of potential fatal cancers worldwide through several intake mechanisms of cesium and iodine and their radioactive byproducts (Ten Hoeve and Jacobson, 2012). This result contradicts the nuclear industry contention that little health impact resulted from this disaster.
Journal Articles on this Report : 23 Displayed | Download in RIS Format
Other project views: | All 66 publications | 23 publications in selected types | All 23 journal articles |
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Ginnebaugh DL, Liang J, Jacobson MZ. Examining the temperature dependence of ethanol (E85) versus gasoline emissions on air pollution with a largely-explicit chemical mechanism. Atmospheric Environment 2010;44(9):1192-1199. |
R833371 (2010) R833371 (Final) |
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Ginnebaugh DL, Jacobson MZ. Coupling of highly explicit gas and aqueous chemistry mechanisms for use in 3-D. Atmospheric Environment 2012;62:408-415. |
R833371 (Final) |
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Ginnebaugh DL, Jacobson MZ. Examining the impacts of ethanol (E85) versus gasoline photochemical production of smog in a fog using near-explicit gas-and aqueous-chemistry mechanisms. Environmental Research Letters 2012;7(4):045901 (8 pp.). |
R833371 (Final) |
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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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Jacobson MZ, Streets DG. Influence of future anthropogenic emissions on climate, natural emissions, and air quality. Journal of Geophysical Research 2009;114(D8):D08118 (21 pp.). |
R833371 (2009) R833371 (2010) R833371 (Final) |
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Jacobson MZ. Enhancement of local air pollution by urban CO2 domes. Environmental Science & Technology 2010;44(7):2497-2502. |
R833371 (2010) R833371 (Final) |
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Jacobson MZ. Short-term effects of controlling fossil-fuel soot, biofuel soot and gases, and methane on climate, Arctic ice, and air pollution health. Journal of Geophysical Research 2010;115(D14):D14209 (24 pp.). |
R833371 (2010) R833371 (Final) |
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Jacobson MZ. Numerical solution to drop coalescence/breakup with a volume-conserving, positive-definite, and unconditionally stable scheme. Journal of the Atmospheric Sciences 2011;68(2):334-346. |
R833371 (2010) R833371 (Final) |
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Jacobson MZ, Ten Hoeve JE. Effects of urban surfaces and white roofs on global and regional climate. Journal of Climate 2012;25(3):1028-1044. |
R833371 (Final) |
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Jacobson MZ. Investigating cloud absorption effects:global absorption properties of black carbon, tar balls, and soil dust in clouds and aerosols. Journal of Geophysical Research-Atmospheres 2012;117(D6):D06205 (25 pp.). |
R833371 (Final) |
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Jacobson MZ. Effects of biomass burning on climate, accounting for heat and moisture fluxes, black and brown carbon, and cloud absorption effects. Journal of Geophysical Research-Atmospheres 2014;119(14):8980-9002. |
R833371 (Final) |
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Jacobson MZ, Ginnebaugh DL. Global-through-urban nested three-dimensional simulation of air pollution with a 13,600-reaction photochemical mechanism. Journal of Geophysical Research 2010;115(D14):D14304 (13 pp.). |
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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Ketefian GS, Jacobson MZ. A mass, energy, vorticity, and potential enstrophy conserving lateral boundary scheme for the shallow water equations using piecewise linear boundary approximations. Journal of Computational Physics 2011;230(8):2751-2793. |
R833371 (2010) R833371 (Final) |
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Stoutenburg ED, Jacobson MZ. Reducing offshore transmission requirements by combining offshore wind and wave farms. IEEE Journal of Oceanic Engineering 2011;36(4):552-561. |
R833371 (Final) |
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Stoutenburg ED, Jenkins N, Jacobson MZ. Variability and uncertainty of wind power in the California electric power system. Wind Energy 2014;17(9):1411-1424. |
R833371 (Final) |
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Ten Hoeve JE, Jacobson MZ, Remer LA. Comparing results from a physical model with satellite and in situ observations to determine whether biomass burning aerosols over the Amazon brighten or burn off clouds. Journal of Geophysical Research-Atmospheres 2012;117(D8):D08203 (19 pp.). |
R833371 (Final) |
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Ten Hoeve JE, Remer LA, Correia AL, Jacobson MZ. Recent shift from forest to savanna burning in the Amazon Basin observed by satellite. Environmental Research Letters 2012;7(2):024020 (8 pp.). |
R833371 (Final) |
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Ten Hoeve JE, Jacobson MZ. Worldwide health effects of the Fukushima Daiichi nuclear accident. Energy & Environmental Science 2012;5(9):8743-8757. |
R833371 (Final) |
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Ten Hoeve JE, Remer LA, Jacobson MZ. Microphysical and radiative effects of aerosols on warm clouds during the Amazon biomass burning season as observed by MODIS: impacts of water vapor and land cover. Atmospheric Chemistry and Physics 2011;11(7):3021-3036. |
R833371 (2010) R833371 (Final) |
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Zamora IR, Tabazadeh A, Golden DM, Jacobson MZ. Hygroscopic growth of common organic aerosol solutes, including humic substances, as derived from water activity measurements. Journal of Geophysical Research-Atmospheres 2011;116(D23):D23207 (12 pp.). |
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:
Mark Z. Jacobson ExitProgress 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.
Project Research Results
- 2010 Progress Report
- 2009 Progress Report
- 2008 Progress Report
- 2007 Progress Report
- Original Abstract
23 journal articles for this project