Energy Production, Consumption, and Consequences (1990) / Chapter Skim
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2. Environmental Issues
2. Environmental Issues
Pages 73-142
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From page 73... ...
Environmental Issues
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From page 75... ...
Although the mean rise in atmospheric temperature is commonly used as an index of climate change, the change in temperature differential between equatorial and polar regions may be a better measure of global environmental forces. The standard point estimate of global warming for a doubling of the concentration of CO2 in the atmosphere is 3° C (National Research Council, 1982~.
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From page 76... ...
Using the commonly accepted 3-degree rise from a doubling of the atmospheric concentration as an approximation to what may be forthcoming, the ensuing temperature will not only be well outside the range of atmospheric temperatures experienced in the past 10,000 years but may be several times the range of temperature variation experienced in that time. This observation is frequently expressed, and correctly, as a change in climate greater than any that mankind has experienced since the dawn of history.
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From page 77... ...
But there is, I acknowledge, another reason why my assessment is so mild. As I mentioned earlier, I am attempting to assess predicted changes, and it may be that our climate models predict only what we understand well enough to include in the models.
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From page 78... ...
The "collapse" of the West Antarctic Ice Sheet would be an altogether different phenomenon. As recently as 15 or 20 years ago, the accepted estimates were that the grounded ice ice resting on the sea bottom and rising a kilometer or more above sea level might, with a warming of the oceans attendant upon a warming of the atmosphere, slide or glaciate into the ocean within 75 years, causing a 20-foot rise in sea level.
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From page 79... ...
in the absence of some international rationing or compensation arrangement, pays alone the cost of its program while sharing the benefits with the rest of the world. Consider the Federal Republic of Germany, which accounts for about 4 percent of world's energy consumption and just about 4 percent of each of the three fossil fuels, coal, oil, and natural gas.
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From page 80... ...
A most ambitious goal might be to reduce by half the growth rate in fossil fuel emissions. (As the fraction of fossil fuels represented by petroleum and natural gas declines over the coming century, fossil fuel consumption will have to increase at less than half the unrestricted growth rate in order that carbon emissions be only half what they might otherwise be.)
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From page 81... ...
When Thomas F Malone was chairman of the Committee on Atmospheric Sciences of the National Research Council, he wrote, 20 years ago, "The possibility that large effects may be produced
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From page 82... ...
Warming the atmosphere currently is more economical than cooling it because it happens as a by-product of energy consumption that would be costly to reduce or terminate. If we were faced with a "little Ice Age" over the next century, we might be glad to get some of that CO2 in the atmosphere at no cost and without having to negotiate climate change diplomatically.
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From page 83... ...
I believe the current wisdom is that we may be in for rising sea level that could be on the order of a meter per century for several centuries (Robin, 1986~. Anything upwards of a meter, perhaps even half a meter, would primarily be due to the collapse of the West Antarctic Ice Sheet.
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From page 84... ...
1983. Future carbon dioxide emissions from fossil fuels.
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From page 85... ...
Regional Environmental Forces: A Methodology for Assessment and Prediction THOMAS E GRAEDEL The ongoing impact of human development on the biosphere is a fact of life.
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From page 86... ...
To say it another way, the work is intended to assist those desiring to become better planetary physicians. TOWARD A SYNOPTIC FRAMEWORK Noteworthy Ionospheric Properties The goal of a synoptic framework is to establish the causal relationships between atmospheric properties that exert significant influence on an ecosystem, and potential sources of change to these properties (and the processes behind them)
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From page 87... ...
Recent advances in our understanding of atmospheric chemistry and its interactions with the biosphere now allow specification of such relationships in terms of fundamental biological, chemical, and physical processes. Interactions Current knowledge about the atmospheric properties affected by changes in specific atmospheric chemicals is given qualitative expression in Figure 1.
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From page 88... ...
plants, soils, and animals on atmospheric chemistry- is also evident in the figure. To complete the connection between the sources of atmospheric chemicals and their influence on the important properties of the atmosphere, it is necessary to account for indirect effects the fact that changes in chemical species A may affect a given atmospheric property through an intermediate influence on chemical species B
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From page 89... ...
Halocarbons Other Halogens Trace Elements 89 FIGURE 1 Direct effects of atmospheric chemistry on important atmospheric properties. The squares indicate that the listed chemical is expected to have a significant direct impact on the listed property.
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From page 90... ...
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From page 91... ...
(1986~. Even more useful for the purposes of policy and management are assessments of the impacts of a single source on several noteworthy atmospheric properties.
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. Figure 4 shows that the sources of most general concern, as indicated by their impact ratings, are almost wholly anthropogenic: fossil fuel combustion, biomass combustion, and industrial processes.
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"Column totals" would, in principle, represent the net effect of all sources on each noteworthy atmospheric property. "Row totals" would indicate the net erect of each source on all noteworthy atmospheric properties.
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From page 94... ...
There is enough evidence to state that a significant decrease in the rate of fossil fuel combustion would tend to stabilize the atmospheric radiation balance, improve visibility, hinder smog formation, and minimize acidic precipitation and its effects. Stratospheric modification is best constrained by devising alternatives to the use of chlorofluorocarbons (CFCs)
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Information is sometimes available also for less widely reported atmospheric constituents or for other locations, although such information is generally unearthed only through informal contacts and negotiated exchanges. Where no measurements have
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From page 96... ...
GRAEDEL Oh Let i: o in L \ \ ATMOSPHERIC PROPERTIES \ 1~. ANAL L' \ \ \ \ loop ]
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From page 97... ...
been made, information on emissions sources such as power plants, industrial processes, and transportation facilities can often suffice to give initial estimates of air quality. As noted, human response to atmospheric impacts depends, in large part, on the current developmental and environmental situations that prevail in a given region.
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From page 98... ...
(1987) , four noteworthy atmospheric properties, photochemical smog, acid precipitation, corrosion of metals, and stratospheric ozone were selected for analysis for the epochs 1890, 1920, 1950, 1980, 2030, and 2080.
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From page 99... ...
REGIONAL ENVIRONMENTAL FORCES TABLE 3 Environmental Quality Assessments for Europe 99 Epocl1 1890 1920 1950 1980 2(80C 21)
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To project atmospheric properties over future epochs, plausible models for development must be formulated to estimate the impacts of biospheric development. These models are initialized and validated by the historical information that is available.
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From page 101... ...
The study did not include the emission controls that may result from the 1987 multinational Montreal Protocol on Substances That Deplete the Ozone Layer, which, if implemented, would reduce the impact of the assessments. Atmospheric Heat Retention The heat retention propensity of the atmosphere, that is, the potential for the greenhouse effect, is directly related to the atmospheric concentration of carbon dioxide and other gases capable of absorbing the outgoing radiation from the earth's surface.
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From page 102... ...
Fossil fuel combustion is the dominant source of CO2 and nitrous oxide as well as the principal source of the precursors of tropospheric ozone and a minor source of methane (Wuebbles and Edmonds, 1988~. Allocation of the global effects of atmospheric heat retention to specific regions can thus be made on the basis of each region's use of fossil fuels and chorofluorocarbons.
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From page 103... ...
103 , ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~, 1~ ~ ~ ~ ~ ~ii~ ~1 o' _ _ _ ~ o 1~-.~1 1~1 ·_ , ~ ~.
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From page 104... ...
For the future, the same sources are expected to be those primarily responsible for the deterioration in regional air quality, with industrial emission of CFCs contributing to stratospheric ozone reduction. Biomass combustion and emission from vegetation and soils will play small roles, especially in photochemical smog production.
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From page 106... ...
In fact, other regimes in the biospheric system are important as well. For example, concern about the cumulative erects of acidic precipitation is based not on the accumulation of certain chemicals in the atmosphere, but rather on the accumulation in other media, such as soil and water, and on the increasing fluxes of precursors of acidic precipitation as a consequence of the growing use of fossil fuels.
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From page 107... ...
107 os — I, _ So ~ .~ ~-~ ~ ~' .= ~~ ~~ ~~ - if -- - ~ , ~ ~-~.~.~.
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From page 108... ...
108 l In — ,, ~ as o s a, o s In o ~ m ~ ~ in, ~ 0 0 0 In In In ~°6, odor odor °~156~ USE' odd odd C)
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From page 109... ...
The methodology presented in this chapter for assessment and prediction of the consequences of environmental forces is primarily applicable to atmospheric impacts at the regional scale, although the approach can be extended to other environmental regimes and time and space scales. It is obvious that global demand for supplies of energr is increasing, and it is equally obvious that the environmental performance of the technologies used to provide that energy will be crucial to the sustainability of the planet itself.
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From page 110... ...
1981. Atmosphere-Biosphere Interactions: Towards a Better Understanding of Ecological Consequences of Fossil Fuel Combustion.
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From page 111... ...
In urban areas both the favorable and the unfavorable environmental aspects of the energy sources selected to operate motor vehicles are important determinants of our quality of life. The urban environmental factors associated with motor vehicle use are the subject of this chapter.
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From page 112... ...
1895-1918~. It is interesting to note the rich variety of energy strategies reported, including motor vehicles built to operate on gunpowder, calcium carbide-acetylene, compressed air, ether, compressed springs, carbonic acid-sestalit, electric battery, alcohols, coal gas, crude petroleum, gasoline, and other energy sources (Bolt, 1980; Hagen, 1977; Ingersoll, 1895, 1897a-e; Staner, 1905~.
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From page 113... ...
, varies widely for these different energy strategies and is greatest for liquid fuels. The alternative energy form closest in performance to petroleum-based fuels is the alcohol fuels: ethanol and methanol.
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From page 114... ...
Figure 2 shows that from 1955 to 1986, petroleum was the largest and the fastest growing segment of total energy consumption. In 1986, 43 percent of total U.S.
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From page 115... ...
The internal combustion engine became the standard because of its inherent energy efficiency. DEVELOPMENT OF EMISSION CONTROL FOR CONVENTIONAL VEHICLES Because motor vehicles burn hydrocarbons using air as the source of oxygen, they emit a variety of combustion products, including carbon dioxide (CO2)
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From page 116... ...
highway vehicles. 1 1 960 ~ , _-, :.::.:: Consumed :~:~:~:.
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From page 117... ...
These observations were verified in numerous smog chamber experiments, which eventually led the Los Angeles Air Pollution Control District to promulgate Rule 66 (Brunelle et al., 1966) , thus making California the first state to legislate emission controls based on the reactivity of hydrocarbons to form smog.
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From page 118... ...
In the 1975 model year, catalytic converters were introduced on motor vehicles, and today more than 80 percent of the in-use passenger car fleet has them (Motor Vehicle Manufacturers Association, 1987~. Regulation and control of hydrocarbon evaporative emissions from motor vehicle carburetors and fuel tanks were first applied in California to 1970 model year vehicles, and federal regulation followed in the next model year.
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From page 119... ...
~ _ _ l l 1 1 1 ,....... :-:-:-::::::::: ::::: ::::: ::::: ::::::::: ::::::::: ·:-:-:-:::::: ::::: :-:-:-: ,, , HC CO NOX HC CO NOX Cars Light Trucks < 8,500 lb ~ Emissions L~J Reduction 119 [~ Emissions [~ i Remaining FIGURE 5 Mandated exhaust emission control reductions from precontrol levels (1991 gasoline motor vehicles)
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From page 120... ...
1970 12 76 1970 12 62 measures the aggregate trend in reducing emissions from all sources, which makes it impossible to assess the progress made by motor vehicles alone. Lead is an exception because its emission is almost exclusively due to the combustion of leaded gasoline, and therefore the measurement is not affected much by other sources.
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From page 121... ...
For example, Houston, considered by some to be the second worst area of the country for ozone pollution, had ozone levels below the standard for 99.47 percent of the hours monitored between 1981 and 1985 (American Petroleum Institute, 1987~. The EPA uses the fourth highest daily maximum 1-hour average ozone value per three consecutive years of data to determine compliance with the standard, because the standard allows for an average of one incident above 0.12 ppm each year.
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From page 122... ...
of total world motor vehicles, much is being learned about the effects of alternative fuel strategies on air quality. The study of air quality effects due to the use of alternative fuels, as well as conventional fuels, has been based on several methods, including atmospheric modeling and smog chamber data using emission rates obtained from vehicles in use, prototype vehicles, and engineering judgment.
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From page 123... ...
, as well as compressed natural gas (CNG) and various methanol fuels (100 percent methanol, referred to as M100, and a mixture of 85 percent methanol and 15 percent gasoline, known as Mew.
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From page 124... ...
Catalysts can be used to remove most of the formaldehyde before it is emitted. However, vehicle data suggest that it does not appear possible, with current technology, to control continuously the more reactive formaldehyde emissions from methanol vehicles to the low level typical of gasoline vehicles over their expected lifetime (Nichols et al., 1988~.
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From page 125... ...
In addition, as shown in Figure 7, nonoxygenated hydrocarbon emissions with M100 fuel were comparable with those of M85 (Nichols et al., 1988) , even though M100 contains no nonoxygenated hydrocarbons.
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From page 126... ...
A typical simulation might be undertaken to seek the upper limit for ozone reduction, assuming that gasoline vehicles have been completely replaced by methanol vehicles. Because actual motor fleet turnover (i.e., new vehicles completely replacing old)
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From page 128... ...
128 ~ _ o :^ ~ ~ o U' z Zen :~: ., ~ 4.)
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From page 129... ...
For most cases, the effect of a switch to methanol, including the effect of emitting some formaldehyde, was investigated under the assumption that the NOX emission rate from methanol vehicles is the same as that from gasoline vehicles. The most recent calculated average reactivity factors for 20 cities were about 0.58 for methanol and 2.15 for formaldehyde, compared with 1.0 for conventional hydrocarbon ozone generation potential at equal carbon emissions.
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From page 130... ...
In addition, because ozone builds up more slowly with methanol, it is necessary to determine the impact of methanol vehicles under multiday episodes of stagnant air, which provide more time for ozone formation. Smog chamber studies of simulated urban air (Carter et al., 1986)
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From page 131... ...
The third case for advanced conventional vehicles assumes that all motor vehicles will be designed to meet the lowest foreseeable emission standards and will perform at the lowest end of the in-use emission range that might be possible with further technical development. The next three cases are methanol scenarios.
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From page 132... ...
Because 0.12 ppm is the value specified by the ozone standard, a 57 percent reduction in ozone level would be required to achieve compliance; this is represented by the top bar of Figure 9 plotted at 100 percent and 0.27 ppm. From Table 4, we note that cases 2 and 3 were found to reduce ozone levels by 3 and 9 percent, respectively; this corresponds, respectively, to 5 and 16 percent of the reduction required to reach the 0.12 ppm level (greater by the ratio of 100/574.
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From page 133... ...
133 ~ _ ~ As_ "o ~ o Vat :Z U
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From page 134... ...
These results suggest that no strategy limited to the motor vehicle transportation system alone will be sufflaent to achieve the ozone standard in the Los Angeles area. SOURCE: California Air Resources Board, 1988.
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From page 135... ...
, EPAs proposed methanol vehicle emission standards (U.S.
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From page 136... ...
Significant technological breakthroughs are required. To illustrate the magnitude of the situation, Figure 10 shows the 1985 emission inventory for both mobile and stationary sources of reactive hydrocarbons and oxides of nitrogen in the South Coast Air Basin (SCAQMD and SCAG, 1987~.
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From page 137... ...
It is critical that consumer concerns be addressed at the outset. 1 400 1 200 >` a, 1 000 Q CO Hi; In z o In CO 400 Level for Ozone Attainment 200 HO _ Nonhighway Automobiles Vehicles Trucks ~ Petroleum Operations NOxi O Residential ~ Electric Power Manufacturing O ServiceCommerce FIGURE 10 South Coast Air Basin emissions lay source for 1985.
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From page 138... ...
There must also be a substantial increase in the production capacity for the alternative fuel in question and a distribution network to make such fuel readily available. Therefore, the development of vehicles having "fuel flexibility" seems imperative in any program to introduce a new fuel.
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From page 139... ...
The renewed interest in alcohol as a fuel in the United States results mainly from a hope that it may reduce environmentally undesirable emissions. Studies suggest that conversion of light~uty vehicles to methanol fuel has some potential to reduce ozone levels if emission assumptions are correct, but they also suggest that in certain areas it is not possible to achieve the ozone standard with any strategy that targets only the emissions from the motor vehicle transportation system.
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From page 140... ...
Los Angeles County Air Pollution Control District. California Air Resources Board (CARB)
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From page 141... ...
South Coast Air Quality Management District (SCAQMD) and Southern California Association of Governments (SCAG)
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From page 142... ...
1986b. Emission Standards for Methanol-Fueled Motor Vehicles and Motor Vehicle Engines, FR 51 No.
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