topic 3 – environmental externalities of urban transportation

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Transport and the Urban Transport and the Urban Environment Environment Topic 3 – Environmental Externalities of Urban Transportation A – Environmental Externalities A – Environmental Externalities B – Local and Regional Externalities B – Local and Regional Externalities C – Global Externalities C – Global Externalities

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Topic 3 – Environmental Externalities of Urban Transportation. A – Environmental Externalities B – Local and Regional Externalities C – Global Externalities. Environmental Externalities. A. 1. Concept 2. Distribution of Costs 3. Types of Emissions 4. Emission Models. Concept. A-1. - PowerPoint PPT Presentation

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Page 1: Topic 3 – Environmental Externalities of Urban Transportation

Transport and the Urban EnvironmentTransport and the Urban Environment

Topic 3 – Environmental Externalities of Urban Transportation

A – Environmental ExternalitiesA – Environmental Externalities

B – Local and Regional ExternalitiesB – Local and Regional Externalities

C – Global Externalities C – Global Externalities

Page 2: Topic 3 – Environmental Externalities of Urban Transportation

Environmental Externalities

1. Concept1. Concept 2. Distribution of Costs2. Distribution of Costs 3. Types of Emissions3. Types of Emissions 4. Emission Models4. Emission Models

AA

Page 3: Topic 3 – Environmental Externalities of Urban Transportation

Concept

A paradox...A paradox... Demands on urban transportation have increased Demands on urban transportation have increased

substantially.substantially. Supports increasing mobility demands.Supports increasing mobility demands. Transport function taken for granted.Transport function taken for granted. Transport costs went down significantly.Transport costs went down significantly.

… … that has consequencesthat has consequences Transport increasingly linked to environmental problems.Transport increasingly linked to environmental problems.

Transportation accounts for 30% of all greenhouse gas Transportation accounts for 30% of all greenhouse gas emissions.emissions.

Technology mostly focused upon the internal combustion Technology mostly focused upon the internal combustion engine.engine.

Spatial accumulation of transportation main factor behind Spatial accumulation of transportation main factor behind the emission of common urban pollutants.the emission of common urban pollutants.

Urban transportation is often subsidized by the society.Urban transportation is often subsidized by the society. Total costs, notably environmental damage, not assumed by Total costs, notably environmental damage, not assumed by

the users.the users.

A-1A-1

Page 4: Topic 3 – Environmental Externalities of Urban Transportation

The Paradox of Mobility and its Costs

Mobility Costs

• Increasing demand• Internal combustion engine• Energy (petroleum)

• Internal costs (users)• External costs (society)• Environmental damage

A-1A-1

Page 5: Topic 3 – Environmental Externalities of Urban Transportation

Concept

DefinitionDefinition Costs that are not assumed by the polluter; the source of Costs that are not assumed by the polluter; the source of

pollution.pollution. Consideration of physical measures of environmental Consideration of physical measures of environmental

damage.damage. Evaluation of involved costs for the society.Evaluation of involved costs for the society. Costs of environmental externalities can be considered from Costs of environmental externalities can be considered from

economic, social and environmental dimensions.economic, social and environmental dimensions. Costs attributed to a few sources (e.g. users of cars) must Costs attributed to a few sources (e.g. users of cars) must

be burdened by the whole society (users and nonusers be burdened by the whole society (users and nonusers alike).alike).

Knowing the origins of environmental externalities is a Knowing the origins of environmental externalities is a relatively easy undertaking.relatively easy undertaking.

Evaluation of the total costs very difficult.Evaluation of the total costs very difficult.

A-1A-1

Page 6: Topic 3 – Environmental Externalities of Urban Transportation

Environmental Externalities

ConceptConcept The environment is a sink.The environment is a sink. Consideration of physical Consideration of physical

measures of environmental measures of environmental damage.damage.

Evaluation of involved costs Evaluation of involved costs for the society.for the society.

Can be considered from Can be considered from economic, social and economic, social and environmental dimensions.environmental dimensions.

Sink

Lithosphere

Hydrosphere

Atmosphere

Ecosphere

A-1A-1

Page 7: Topic 3 – Environmental Externalities of Urban Transportation

Environmental Externalities

Level of intervention

Optimal cost

Total costs

ExternalitiesIntervention costs

Costs

A-1A-1

Page 8: Topic 3 – Environmental Externalities of Urban Transportation

A-1A-1 Estimated Automobile Costs, 1996

22%

16%62%

External costsInternal fixed costsInternal variable costs

Internal variable costsInternal variable costs Vary according to the Vary according to the

amount of travel.amount of travel. Include vehicle operation Include vehicle operation

and travel time. and travel time. Internal fixed costsInternal fixed costs

Related to the vehicle Related to the vehicle ownership and parking fees.ownership and parking fees.

Depreciation, insurance, Depreciation, insurance, finance charge, license fee, finance charge, license fee, etc. etc.

External costsExternal costs Not assumed by individual Not assumed by individual

users but by the collectivity. users but by the collectivity. Include environmental Include environmental

damage.damage.

Page 9: Topic 3 – Environmental Externalities of Urban Transportation

Distribution of Costs

RelationshipsRelationships Several relationships are not known and / or difficult to Several relationships are not known and / or difficult to

evaluate.evaluate. Quantification is only at its preliminary stage.Quantification is only at its preliminary stage. Many polluters used this argument to differ the application of Many polluters used this argument to differ the application of

several environmental policies by lobbying governments several environmental policies by lobbying governments (e.g. acid rain and CFCs). (e.g. acid rain and CFCs).

Bearing the consequencesBearing the consequences The emitters of pollutants rarely bear the consequences of The emitters of pollutants rarely bear the consequences of

their impacts and costs for the society.their impacts and costs for the society. Users only take account of the direct costs of ownership like Users only take account of the direct costs of ownership like

a car (vehicle, fuel, insurance, etc.).a car (vehicle, fuel, insurance, etc.). Possession is often the only entry and utilization cost for Possession is often the only entry and utilization cost for

several transportation modes.several transportation modes.

A-2A-2

Page 10: Topic 3 – Environmental Externalities of Urban Transportation

Distribution of Costs

The society generally assumes costsThe society generally assumes costs Providing and maintaining infrastructure.Providing and maintaining infrastructure. Damage to structures and infrastructure.Damage to structures and infrastructure. Losses in productivity (agriculture and labor).Losses in productivity (agriculture and labor). Cleanup.Cleanup. Health services.Health services. Damage to ecosystems.Damage to ecosystems.

Geographic separation between sources and Geographic separation between sources and recipientsrecipients Acid rains and greenhouse effects are obvious examples.Acid rains and greenhouse effects are obvious examples. A community may be affected by noise levels well over its A community may be affected by noise levels well over its

own contribution (notably near major highways).own contribution (notably near major highways). Another (suburbs) may be affected in a very marginal way Another (suburbs) may be affected in a very marginal way

and still significantly contributes to noise elsewhere during and still significantly contributes to noise elsewhere during commuting. commuting.

A-2A-2

Page 11: Topic 3 – Environmental Externalities of Urban Transportation

Distribution of Costs

QuantificationQuantification Economic, social and environmental costs.Economic, social and environmental costs. Very difficult but possible if we accept some simplifications Very difficult but possible if we accept some simplifications

and generalizations.and generalizations. Land transportation:Land transportation:

Noise related costs account for 0.1% of GDP.Noise related costs account for 0.1% of GDP. Health (social) from 0.04% to 0.11% of GDP.Health (social) from 0.04% to 0.11% of GDP. Damage to structures and infrastructure 0.07% and Damage to structures and infrastructure 0.07% and

between 0.1% of GDP.between 0.1% of GDP. 0.16% of GDP for damage to the natural environment. 0.16% of GDP for damage to the natural environment.

The important contribution of transportation to environmental The important contribution of transportation to environmental externalities.externalities.

A-2A-2

Page 12: Topic 3 – Environmental Externalities of Urban Transportation

Types of Emissions

Cold StartCold Start Vehicle engine has been turned off for some time and the Vehicle engine has been turned off for some time and the

catalytic converter (if present) is cold.catalytic converter (if present) is cold. HC and CO emissions are higher when a cold engine is first HC and CO emissions are higher when a cold engine is first

started than after the vehicle is warmed up.started than after the vehicle is warmed up. Catalytic emission control systems do not provide full control Catalytic emission control systems do not provide full control

until they reach operating temperature.until they reach operating temperature. Richer fuel air mixture must be provided to the cylinders Richer fuel air mixture must be provided to the cylinders

under cold operating conditions to achieve satisfactory under cold operating conditions to achieve satisfactory engine performance.engine performance.

Extra fuel is added to ensure that an adequate amount of Extra fuel is added to ensure that an adequate amount of fuel is vaporized to achieve a combustible mixture.fuel is vaporized to achieve a combustible mixture.

Complete vaporization eventually occurs in the engine Complete vaporization eventually occurs in the engine cylinder as a result of the high temperatures created by cylinder as a result of the high temperatures created by combustion.combustion.

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Page 13: Topic 3 – Environmental Externalities of Urban Transportation

Types of Emissions

Fuel cannot be completely burned due to a lack of sufficient Fuel cannot be completely burned due to a lack of sufficient oxygen in the cylinder.oxygen in the cylinder.

Partially burned fuel and unburned fuel are emitted in Partially burned fuel and unburned fuel are emitted in relatively high concentrations from a cold engine.relatively high concentrations from a cold engine.

Hot StartHot Start Engine has been turned off for such a short time that the Engine has been turned off for such a short time that the

catalyst has not had time to cool to ambient temperature.catalyst has not had time to cool to ambient temperature. HC and CO hot start emissions are significantly lower than HC and CO hot start emissions are significantly lower than

under cold start operation.under cold start operation. Hot StabilizedHot Stabilized

Engine and emission control systems have reached full Engine and emission control systems have reached full operating temperatures.operating temperatures.

Generally, emissions are relatively low (compared to cold Generally, emissions are relatively low (compared to cold start emission rates) under hot stabilized conditions.start emission rates) under hot stabilized conditions.

However, emissions are also highly dependent on vehicle However, emissions are also highly dependent on vehicle speed and engine load.speed and engine load.

A-3A-3

Page 14: Topic 3 – Environmental Externalities of Urban Transportation

Types of Emissions

Idle EmissionsIdle Emissions Emissions when the vehicle is not moving.Emissions when the vehicle is not moving. Often occur during congestion.Often occur during congestion. Lower levels of emission, but still significant since the fuel Lower levels of emission, but still significant since the fuel

burned does not provide anything useful.burned does not provide anything useful. Hot SoakHot Soak

Occurs when a hot engine is turned off.Occurs when a hot engine is turned off. Fuel exposed to the engine (e.g., in carburetor float bowls or Fuel exposed to the engine (e.g., in carburetor float bowls or

in fuel injectors) may evaporate and escape to the in fuel injectors) may evaporate and escape to the atmosphere.atmosphere.

Running Losses Running Losses Resulting from vapor generated in gasoline fuel tanks during Resulting from vapor generated in gasoline fuel tanks during

engine operation.engine operation. Problem on vehicles that have exhaust systems in close Problem on vehicles that have exhaust systems in close

proximity to the gasoline tank.proximity to the gasoline tank. Vapors emitted from the tank vent exceed the rate at which Vapors emitted from the tank vent exceed the rate at which

they are being purged from the canister by the engine.they are being purged from the canister by the engine.

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Types of Emissions

Resting LossesResting Losses Emissions resulting from vapors permeating parts of the Emissions resulting from vapors permeating parts of the

evaporative emission control system. evaporative emission control system. Significant HC emissions, especially in warm areas where Significant HC emissions, especially in warm areas where

the fuel take has an higher vapor pressure.the fuel take has an higher vapor pressure. Refueling LossesRefueling Losses

Vapor space displacement and spillage.Vapor space displacement and spillage. As a fuel tank is being refueled, the incoming liquid fuel As a fuel tank is being refueled, the incoming liquid fuel

displaces gasoline vapor.displaces gasoline vapor. Pushing the vapor out of the tank.Pushing the vapor out of the tank. Spillage simply refers to a small amount of fuel that is Spillage simply refers to a small amount of fuel that is

assumed to drip on the ground and subsequently evaporate assumed to drip on the ground and subsequently evaporate into the ambient air.into the ambient air.

A-3A-3

Page 16: Topic 3 – Environmental Externalities of Urban Transportation

Emission Models

PurposePurpose Evaluate the air quality impacts of the fleet.Evaluate the air quality impacts of the fleet. Indicate progresses in meeting or complying to air quality Indicate progresses in meeting or complying to air quality

standards.standards. Help identify where efforts should be placed to improve Help identify where efforts should be placed to improve

environmental quality.environmental quality. Track the emission impacts of:Track the emission impacts of:

Technology changes.Technology changes. Changes in travel patterns.Changes in travel patterns. Changes in vehicle sales.Changes in vehicle sales.

MOBILEMOBILE Emission model developed by the American EPA.Emission model developed by the American EPA. Provides exhaust hydrocarbon (HC), carbon monoxide (CO), Provides exhaust hydrocarbon (HC), carbon monoxide (CO),

and oxides of nitrogen (NOx) emission rates (in grams/mile) and oxides of nitrogen (NOx) emission rates (in grams/mile) for eight separate vehicle categories.for eight separate vehicle categories.

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Page 17: Topic 3 – Environmental Externalities of Urban Transportation

Components of the MOBILE Emission Model

Fleet Characteristics Driving Characteristics

Atmospheric Conditions Fuel Characteristics

Emissions

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Page 18: Topic 3 – Environmental Externalities of Urban Transportation

Emission Models

Fleet characteristicsFleet characteristics Weight of the vehicle and its load has a direct impact on Weight of the vehicle and its load has a direct impact on

combustion.combustion. Aerodynamics.Aerodynamics. Vehicle age and accumulated mileage.Vehicle age and accumulated mileage. Friction between its parts (gear, transmission, brakes, Friction between its parts (gear, transmission, brakes,

wheels, etc.).wheels, etc.). Base emission rate.Base emission rate.

A new vehicle has a set of emission rates.A new vehicle has a set of emission rates. As a vehicle ages, it tends to consume more fuel As a vehicle ages, it tends to consume more fuel

because its parts become less efficient.because its parts become less efficient. Older vehicles tend to have higher emission levels.Older vehicles tend to have higher emission levels.

Technological improvements, like catalytic converters, have Technological improvements, like catalytic converters, have significantly reduced CO, CO2, and HC emissions but have significantly reduced CO, CO2, and HC emissions but have increased NOx emissions.increased NOx emissions.

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Page 19: Topic 3 – Environmental Externalities of Urban Transportation

Emission Models

Driving characteristicsDriving characteristics Also referred as test conditions.Also referred as test conditions. Optimal speed of a vehicle ranges around 60 km per hour.Optimal speed of a vehicle ranges around 60 km per hour. Transportation system permitting optimal travel speeds and Transportation system permitting optimal travel speeds and

uninterrupted flows would provide minimal combustion levels uninterrupted flows would provide minimal combustion levels and emission factors.and emission factors.

Real road conditions, particularly in urban areas, do not Real road conditions, particularly in urban areas, do not enable optimal travel speeds.enable optimal travel speeds.

Congestion, traffic signals and freeways have a high Congestion, traffic signals and freeways have a high tendency to discriminate travel speeds.tendency to discriminate travel speeds.

Raise combustion and emission levels.Raise combustion and emission levels. Majority of urban vehicle-km traveled are at speeds other Majority of urban vehicle-km traveled are at speeds other

than the optimal.than the optimal.

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Page 20: Topic 3 – Environmental Externalities of Urban Transportation

Emission Models

Atmospheric conditionsAtmospheric conditions Influence combustion in a direct manner.Influence combustion in a direct manner. Low temperatures increase combustion, and indirectly road Low temperatures increase combustion, and indirectly road

conditions.conditions. During winter car engines require more energy to warm up During winter car engines require more energy to warm up

(cold start) and keep comfortable conditions for passengers.(cold start) and keep comfortable conditions for passengers. Snow and rain accumulation, wind and impaired visibility Snow and rain accumulation, wind and impaired visibility

increase combustion.increase combustion. Cooling systems for the engine and the passenger consume Cooling systems for the engine and the passenger consume

more energy as the ambient temperature rises.more energy as the ambient temperature rises. Cold temperatures increase CO and HC emissions. Cold temperatures increase CO and HC emissions.

Fuel characteristicsFuel characteristics Level of fuel volatility.Level of fuel volatility. Oxygenate content.Oxygenate content. Influence both evaporative and exhaust emission rates.Influence both evaporative and exhaust emission rates.

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Page 21: Topic 3 – Environmental Externalities of Urban Transportation

Inputs and Outputs of the MOBILE Emission Model

Volatility Class

Temperature

Reid Vapor Pressure

Region

Year

Average Speed

Operating Mode

HC Emissions

CO Emissions

NOx Emissions

8 categories of vehicles

Inputs Outputs

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Page 22: Topic 3 – Environmental Externalities of Urban Transportation

Emissions of Pollutants by Cars for Different Speeds

1

10

100

1000

5 10 20 30 35 45 55 60 70 80 85 95 100

Speed (km per hour)

Emis

sion

s (g

ram

s)

0

2

4

6

8

10

12

14

16

18

20

% o

f veh

icle

-km

% of vehicle-km

HC

CO

NOx

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Page 23: Topic 3 – Environmental Externalities of Urban Transportation

Annual Emissions of Air Pollutants for a Passenger Car in the United States, 1997

1 10 100 1000 10000

Hydrocarbons

Carbon Monoxide

Nitrogren Oxides

Carbon Dioxide

kg / vehicle / year

1 10 100 1000grams per mile

kg / veh / year

grams per mile

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Page 24: Topic 3 – Environmental Externalities of Urban Transportation

Annual Emissions of Air Pollutants for a Light Truck in the United States, 1997

1 10 100 1000 10000

Hydrocarbons

Carbon Monoxide

Nitrogren Oxides

Carbon Dioxide

kg / vehicle / year

1 10 100 1000grams per mile

kg / veh / year

grams per mile

A-4A-4

Page 25: Topic 3 – Environmental Externalities of Urban Transportation

Local and Regional Externalities

1. Air Pollutants1. Air Pollutants 2. Water Pollutants2. Water Pollutants 3. Noise3. Noise

BB

Page 26: Topic 3 – Environmental Externalities of Urban Transportation

Local Structure and Exposure

Traffic emissions

Buffer

Habitat

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Page 27: Topic 3 – Environmental Externalities of Urban Transportation

Air Pollutants

ContextContext The most important source of environmental externalities for The most important source of environmental externalities for

transportation.transportation. The nature of air pollutants is clearly identified.The nature of air pollutants is clearly identified. The scale and scope on how they influence the biosphere The scale and scope on how they influence the biosphere

are subject to much controversy.are subject to much controversy. Carbon MonoxideCarbon Monoxide

Colorless, odorless gas and poisonous.Colorless, odorless gas and poisonous. Result of the incomplete combustion of hydrocarbons. Result of the incomplete combustion of hydrocarbons. Transportation accounts from 70 to 90% of total carbon Transportation accounts from 70 to 90% of total carbon

monoxide emissions.monoxide emissions. The air pollutant the most strongly associated with The air pollutant the most strongly associated with

transportation.transportation. Present near major traffic intensive arterials, notably in Present near major traffic intensive arterials, notably in

urban areas.urban areas. When inhaled, it combines with hemoglobin to form When inhaled, it combines with hemoglobin to form

carboxyhemoglobin.carboxyhemoglobin.

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Air Pollutants

Preventing absorption of oxygen and resulting in Preventing absorption of oxygen and resulting in asphyxiation.asphyxiation.

0.5% of carbon monoxide in air may prove fatal in less than 0.5% of carbon monoxide in air may prove fatal in less than half an hour by transforming over 50% of the hemoglobin in half an hour by transforming over 50% of the hemoglobin in carboxyhemoglobin.carboxyhemoglobin.

Lower concentrations of carbon monoxide (3 ppm) may Lower concentrations of carbon monoxide (3 ppm) may cause poisoning symptoms and affect people with heart, cause poisoning symptoms and affect people with heart, lung and circulatory system weaknesses.lung and circulatory system weaknesses.

Also effects the respiration of plants by inhibiting Also effects the respiration of plants by inhibiting photosynthesis. photosynthesis.

Since carbon monoxide is not chemically very stable, direct Since carbon monoxide is not chemically very stable, direct global effects are strongly limited (probably non existent).global effects are strongly limited (probably non existent).

Indirectly, carbon monoxide contributes to the formation of Indirectly, carbon monoxide contributes to the formation of greenhouse gazes as a catalyst.greenhouse gazes as a catalyst.

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Page 29: Topic 3 – Environmental Externalities of Urban Transportation

Air Pollutants

Nitrogen oxide (NO or NO2)Nitrogen oxide (NO or NO2) Brown, odorless gas.Brown, odorless gas. A by-product of combustion when energy is used to oxide A by-product of combustion when energy is used to oxide

nitrogen instead of an hydrocarbon. nitrogen instead of an hydrocarbon. Transportation accounts from 45 to 50% of total emissions Transportation accounts from 45 to 50% of total emissions

of nitrogen oxides.of nitrogen oxides. Other sources:Other sources:

Chemicals (notably nitrates) industrial production.Chemicals (notably nitrates) industrial production. Combustion of fossil fuels in thermal power plants. Combustion of fossil fuels in thermal power plants.

Nitrogen oxides are not very harmful to humans (particularly Nitrogen oxides are not very harmful to humans (particularly NO), but when released from an internal combustion engine, NO), but when released from an internal combustion engine, high concentrations are often toxic.high concentrations are often toxic.

It irritates and infects the respiratory system and the eyes.It irritates and infects the respiratory system and the eyes. Some decreases in the ability to resist bacterial infection Some decreases in the ability to resist bacterial infection

were observed when exposed to significant concentrations were observed when exposed to significant concentrations of nitrogen dioxide.of nitrogen dioxide.

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Air Pollutants

Nitrogen oxides are known to prevent the growth of crops Nitrogen oxides are known to prevent the growth of crops and thus reduce agricultural yields. and thus reduce agricultural yields.

Increased at a rate of 0.2% annually over the last decades.Increased at a rate of 0.2% annually over the last decades. They are a catalyst for ozone, a component of acid rain and They are a catalyst for ozone, a component of acid rain and

a component of smog.a component of smog. Depositions of nitrogen oxides influence the nitrate cycle, Depositions of nitrogen oxides influence the nitrate cycle,

particularly in water where it influences algae blooms.particularly in water where it influences algae blooms.

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SO2 and NOx Emissions in North America and Europe, 1980-1994

30,000

35,000

40,000

45,000

50,000

55,000

60,000

1980 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994

(000

met

ric

tons

)

NOx

SO2

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Percentage Contributions of Vehicle Types to Emissions of NOx in the UK, 1997

54%

7%

32%

7%

Cars

Vans

Trucks

Other

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Air Pollutants

Hydrocarbons and Volatile Organic Compounds - Hydrocarbons and Volatile Organic Compounds - (HC/VOC)(HC/VOC) Hydrocarbons (HC) are a group of chemical compound Hydrocarbons (HC) are a group of chemical compound

composed of carbon and hydrogen.composed of carbon and hydrogen. When in a gaseous form, HC are called Volatile Organic When in a gaseous form, HC are called Volatile Organic

Compounds (VOC).Compounds (VOC). Several HC and VOC are heavy gazes or volatile Several HC and VOC are heavy gazes or volatile

compounds with a strong odor.compounds with a strong odor. Mostly the result of the incomplete combustion of gasoline or Mostly the result of the incomplete combustion of gasoline or

by-products of the petrochemical industry.by-products of the petrochemical industry. Include methane (CH4), gasoline (C8H18) and diesel Include methane (CH4), gasoline (C8H18) and diesel

vapours, benzene (C6H6), formaldehyde (CH2O), butadiene vapours, benzene (C6H6), formaldehyde (CH2O), butadiene (C4H6) and acetaldehyde (CH3CHO). (C4H6) and acetaldehyde (CH3CHO).

Transportation accounts from 40 to 50% of total emissions Transportation accounts from 40 to 50% of total emissions of HC/VOC.of HC/VOC.

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Air Pollutants

Emitted by incomplete combustion (70%), during refueling Emitted by incomplete combustion (70%), during refueling (10%) or by evaporation from storage units (20%), (10%) or by evaporation from storage units (20%), particularly gas tanks.particularly gas tanks.

A car parked overnight during summer emits A car parked overnight during summer emits approximately 4 grams of HC/VOC.approximately 4 grams of HC/VOC.

Other important sources are petrochemical (plastics and Other important sources are petrochemical (plastics and solvent) industries. solvent) industries.

ImpactsImpacts All HC/VOC are carcinogen (cases of leukemia linked All HC/VOC are carcinogen (cases of leukemia linked

with benzene) to some extent.with benzene) to some extent. Fatal at high concentrations.Fatal at high concentrations. Harmful to crops and accumulates within the food chain.Harmful to crops and accumulates within the food chain. Heavy hydrocarbons (like benzene) are far more Heavy hydrocarbons (like benzene) are far more

carcinogen than light hydrocarbons (like methane). carcinogen than light hydrocarbons (like methane). All HC/VOC have several global effects.All HC/VOC have several global effects. They are components of smog, catalysts for ozone and They are components of smog, catalysts for ozone and

components of acid rain.components of acid rain.

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Air Pollutants

ParticulatesParticulates Various solids in suspension such as smoke, soot, and dust.Various solids in suspension such as smoke, soot, and dust. Results of the incomplete combustion of fossil fuels, notably coal. Results of the incomplete combustion of fossil fuels, notably coal. May also carry traces of other toxic substances like HC/VOC. May also carry traces of other toxic substances like HC/VOC. Transportation accounts for around 25% of total emissions.Transportation accounts for around 25% of total emissions.

Diesel engines are the main emitters.Diesel engines are the main emitters. Other important sources are thermal power plants using coal. Other important sources are thermal power plants using coal.

Particulates are carcinogen.Particulates are carcinogen. Harmful to lungs tissue.Harmful to lungs tissue. Worsen respiratory and cardiovascular problems, notably if Worsen respiratory and cardiovascular problems, notably if

their size is smaller than 5 microns.their size is smaller than 5 microns. Particulates depositions may alter the aesthetic of structures.Particulates depositions may alter the aesthetic of structures. The accumulation of particulates in the atmosphere and deposition The accumulation of particulates in the atmosphere and deposition

on leafs may reduce photosynthesis and plant growth.on leafs may reduce photosynthesis and plant growth.

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Percentage Contributions of Vehicle Types to Emissions of Particulate Matter in the UK, 1997

30%

18%

42%

10%

Cars

Vans

Trucks

Other

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Air Pollutants

SmogSmog Mixture of solid and liquid fog and smoke particles.Mixture of solid and liquid fog and smoke particles.

Carbon monoxide.Carbon monoxide. Ozone.Ozone. HC/VOC.HC/VOC. Nitrogen oxides.Nitrogen oxides. Sulfur oxide.Sulfur oxide. Water vapor.Water vapor. Particulates, and other chemical pollutants.Particulates, and other chemical pollutants.

Photochemical smog are those with a higher concentration Photochemical smog are those with a higher concentration of ozone and HC/VOC. of ozone and HC/VOC.

Strongly linked with transportation and industrial activities, Strongly linked with transportation and industrial activities, notably in urban areas.notably in urban areas.

Particularly dense during a thermal inversion (static regional Particularly dense during a thermal inversion (static regional air masses that enable the accumulation of pollutants). air masses that enable the accumulation of pollutants).

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Air Pollutants

The effects of smog are the conjunction of those of its major The effects of smog are the conjunction of those of its major components.components.

Deaths among susceptible persons (respiratory and Deaths among susceptible persons (respiratory and cardiovascular problems) grows sharply during thermal cardiovascular problems) grows sharply during thermal inversions. inversions.

Several large cities (like Los Angeles, Tokyo and Mexico) Several large cities (like Los Angeles, Tokyo and Mexico) have serious smog problems.have serious smog problems.

Emissions reduction policies were established.Emissions reduction policies were established. Stricter emission controls.Stricter emission controls. Alternance of driving days.Alternance of driving days.

Smog impairs visibility considerably and causes different Smog impairs visibility considerably and causes different annoyances (odors, irritations, etc.).annoyances (odors, irritations, etc.).

Because of its components, smog is highly associated with Because of its components, smog is highly associated with acid rains and greenhouse effects. acid rains and greenhouse effects.

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Air Pollutants

LeadLead Toxic metal mainly used as an anti-knock agent in gasoline (Lead Toxic metal mainly used as an anti-knock agent in gasoline (Lead

tetraethyl - Pb(C2H5)4) and in batteries (lead dioxide as an anode tetraethyl - Pb(C2H5)4) and in batteries (lead dioxide as an anode and lead as a cathode). and lead as a cathode).

Until recently, lead tetraethyl was a main source of atmospheric Until recently, lead tetraethyl was a main source of atmospheric lead emissions in developing countries.lead emissions in developing countries.

This contribution has dropped in absolute numbers but still This contribution has dropped in absolute numbers but still accounts for 30 to 40% of total emissions.accounts for 30 to 40% of total emissions.

Batteries are an important source of lead for transportation, but a Batteries are an important source of lead for transportation, but a very limited amount of this lead is carried through the atmosphere.very limited amount of this lead is carried through the atmosphere.

Extremely poisonous metal.Extremely poisonous metal. Has effects on the metabolism and accumulates in living Has effects on the metabolism and accumulates in living

tissues.tissues. May causes anemia and mental retardation for young children.May causes anemia and mental retardation for young children. An extremely high occurrence of mental retardation in some An extremely high occurrence of mental retardation in some

parts of Mexico city was directly linked with lead poisoning.parts of Mexico city was directly linked with lead poisoning. Small doses may cause behavioral changes. Small doses may cause behavioral changes.

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Page 40: Topic 3 – Environmental Externalities of Urban Transportation

Countries Still Using Lead Gasoline, 1995

USE LEADEDGASOLINE

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Page 41: Topic 3 – Environmental Externalities of Urban Transportation

Air Pollutants

Fixed by plants and animals and re-contaminate the food chain.Fixed by plants and animals and re-contaminate the food chain. Has a high potential to accumulate in the environment.Has a high potential to accumulate in the environment. Can be transported in the atmosphere over wide distances.Can be transported in the atmosphere over wide distances.

OdorsOdors Subjective perception of the sense of smell.Subjective perception of the sense of smell. Different "shapes" of odors perceived as pleasant, neutral, or Different "shapes" of odors perceived as pleasant, neutral, or

unpleasant.unpleasant. Long run exposition to specific odors attenuates their perception. Long run exposition to specific odors attenuates their perception. Diesel and gasoline engines are the major sources of odors Diesel and gasoline engines are the major sources of odors

accounted by transportation.accounted by transportation. Odors are particularly prevalent during smog conditions.Odors are particularly prevalent during smog conditions. At worst an annoyance, but they are linked with the presence of At worst an annoyance, but they are linked with the presence of

harmful air pollutants like sulfur dioxide, ozone and HC/VOC.harmful air pollutants like sulfur dioxide, ozone and HC/VOC. People tend to stay or move away from areas having a significant People tend to stay or move away from areas having a significant

prevalence of odors. prevalence of odors.

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Contribution of Transportation in the Emission of Major Air Pollutants in Selected Countries, 1980 (%)

0 20 40 60 80 100

Canada

United States

Australia

France

Germany

Italy

Sweden

United Kingdom

HC

CO

NOx

Particulates

SOx

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Water Pollutants

Air Pollution FalloutsAir Pollution Fallouts Occur when a pollutant goes from an airborne state (gas, Occur when a pollutant goes from an airborne state (gas,

solid or liquid) towards a solute or colloidal state.solid or liquid) towards a solute or colloidal state. Water is a very good solvent for several pollutants, notably Water is a very good solvent for several pollutants, notably

acid depositions.acid depositions. Accelerated and concentrated in an area by rainy conditions. Accelerated and concentrated in an area by rainy conditions. As an important source of air pollution, transportation As an important source of air pollution, transportation

accounts on a similar scale for fallouts.accounts on a similar scale for fallouts. In some areas transportation may account for up to 25% of In some areas transportation may account for up to 25% of

nitrogen fallouts in water.nitrogen fallouts in water. Sulfuric and nitric acids that may alter the pH of water if they Sulfuric and nitric acids that may alter the pH of water if they

are present in sufficient concentrations.are present in sufficient concentrations. It is estimated that acid rains may account for more than It is estimated that acid rains may account for more than

75% of the growth of acidity of lakes. 75% of the growth of acidity of lakes.

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Water Pollutants

Several northeastern United States and eastern Canadian Several northeastern United States and eastern Canadian lakes have seen their entire fish population destroyed as a lakes have seen their entire fish population destroyed as a result of increased acidity levels.result of increased acidity levels.

Also includes damage to forests like reduced photosynthesis Also includes damage to forests like reduced photosynthesis (sparse foliage) and acidified soils (limited nutrients).(sparse foliage) and acidified soils (limited nutrients).

Nitrous oxides may affect the ecological balance of marine Nitrous oxides may affect the ecological balance of marine life by favoring algae blooms. life by favoring algae blooms.

Fallouts such as HC/VOC and lead are poisonous and may Fallouts such as HC/VOC and lead are poisonous and may disrupt marine life if they accumulate in the aquatic food disrupt marine life if they accumulate in the aquatic food chain.chain.

May increase the turbidity of water and thus reduce the May increase the turbidity of water and thus reduce the photosynthesis capacity of aquatic plants.photosynthesis capacity of aquatic plants.

Long term accumulation of air pollution fallouts of various Long term accumulation of air pollution fallouts of various nature will contaminate and disrupt whole aquatic nature will contaminate and disrupt whole aquatic ecosystems.ecosystems.

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Water Pollutants

De-Icing of InfrastructureDe-Icing of Infrastructure Salt (NaCl) lowers the melting point of water.Salt (NaCl) lowers the melting point of water. Presents an useful compound for keeping safe road Presents an useful compound for keeping safe road

conditions in sub-zero climates.conditions in sub-zero climates. Other elements like sand and gravel are also added to Other elements like sand and gravel are also added to

provide adherence. provide adherence. Infrastructure involve roads, parking lots, airfields etc.Infrastructure involve roads, parking lots, airfields etc. Almost the only artificial source of salt release in the Almost the only artificial source of salt release in the

environment.environment. Other compounds like calcium and magnesium can be used, Other compounds like calcium and magnesium can be used,

but they work more slowly and cost ten times as much.but they work more slowly and cost ten times as much. High concentrations in fresh water environments disrupt life High concentrations in fresh water environments disrupt life

cycles and may be fatal to some organisms like larvae.cycles and may be fatal to some organisms like larvae.

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Water Pollutants

De-icing salt has the tendency to accumulate in snow and De-icing salt has the tendency to accumulate in snow and soils beside roadways.soils beside roadways.

During early springtime, nearly all the salt accumulated During early springtime, nearly all the salt accumulated will be released in the hydrographic system.will be released in the hydrographic system.

Contaminate ground water and interfere with the growth Contaminate ground water and interfere with the growth of plants and the reproduction cycle of aquatic life.of plants and the reproduction cycle of aquatic life.

RunoffsRunoffs Substances accumulated by a surface (notably a road) are Substances accumulated by a surface (notably a road) are

dissolved / carried by water and evacuated elsewhere.dissolved / carried by water and evacuated elsewhere. Often the convergence of a surface to a point.Often the convergence of a surface to a point. Lubricants from car leakages - engine, brakes, and Lubricants from car leakages - engine, brakes, and

transmission).transmission). Heavy metals (Zn, Cd, Cu, Ni, Cr and Fe ) from abrasion of Heavy metals (Zn, Cd, Cu, Ni, Cr and Fe ) from abrasion of

tires and brake linings.tires and brake linings. Dry fallouts (HC/VOC, particulates). Dry fallouts (HC/VOC, particulates).

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Water Pollutants

Road infrastructure (parking lots, roads, drainage systems) Road infrastructure (parking lots, roads, drainage systems) is the major source of runoffs.is the major source of runoffs.

Highways occupy 5-8% of the urban catchment area.Highways occupy 5-8% of the urban catchment area. Contribute for as much as 50% of the total suspended Contribute for as much as 50% of the total suspended

solids, 16% of the total HC and 75% of the total metal solids, 16% of the total HC and 75% of the total metal inputs to a receiving stream. inputs to a receiving stream.

Will alter the turbidity and the oxygen level of water (warm Will alter the turbidity and the oxygen level of water (warm water holds less oxygen), and contaminate the food chain.water holds less oxygen), and contaminate the food chain.

May increase the eutrophication process of several lakes, May increase the eutrophication process of several lakes, particularly in recreational areas where dirt roads are dense.particularly in recreational areas where dirt roads are dense.

Most cities have 30 to 70% of their surface occupied by Most cities have 30 to 70% of their surface occupied by roads and parking space.roads and parking space.

They represent important sources of runoffs.They represent important sources of runoffs.

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Water Pollutants

Construction and Maintenance of InfrastructureConstruction and Maintenance of Infrastructure Several transportation infrastructures have important Several transportation infrastructures have important

territorial handholds.territorial handholds. The removal of natural habitats along shorelines is one of The removal of natural habitats along shorelines is one of

the most important impact.the most important impact. Road transportation:Road transportation:

Accounts for most of the territorial handhold of Accounts for most of the territorial handhold of transportation.transportation.

Structures like bridges and parking facilities.Structures like bridges and parking facilities. Maritime transportation:Maritime transportation:

Several disruptive infrastructure like piers, canals, Several disruptive infrastructure like piers, canals, harbors and terminals.harbors and terminals.

Dredging accounts alone for 80% of the waste released Dredging accounts alone for 80% of the waste released in aquatic environments.in aquatic environments.

Influences the turbidity of water and destroys habitats.Influences the turbidity of water and destroys habitats.

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Water Pollutants

Airports have similar effects when constructed over wetland.Airports have similar effects when constructed over wetland. Chek Lap Kok airport in Hong Kong.Chek Lap Kok airport in Hong Kong.

The aquatic / land interface to which several animal and The aquatic / land interface to which several animal and vegetal species depend is considerably reduced.vegetal species depend is considerably reduced.

Roads and rails, when running through wetland, reduce the Roads and rails, when running through wetland, reduce the water regeneration / purification.water regeneration / purification.

Splitting available areas and disrupting water flows.Splitting available areas and disrupting water flows. Large ports occupy extensive areas along the shorelines of Large ports occupy extensive areas along the shorelines of

waterways and coasts.waterways and coasts. Construction and maintenance of port infrastructure have Construction and maintenance of port infrastructure have

extensive impacts over aquatic environments.extensive impacts over aquatic environments. Construction of canals:Construction of canals:

Xhanges whole hydrographic systems.Xhanges whole hydrographic systems. Altering water flows (quantity and speed) at regional and Altering water flows (quantity and speed) at regional and

often at continental levels.often at continental levels.

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Noise

DefinitionDefinition Noise (air and infrastructure vibration) is an inherent Noise (air and infrastructure vibration) is an inherent

characteristic of transportation.characteristic of transportation. Noise is an undesirable sound.Noise is an undesirable sound. Representation of noise emissions:Representation of noise emissions:

Point (a vehicle).Point (a vehicle). Line (a highway).Line (a highway). Surface (ambient noise generated by a set of streets) Surface (ambient noise generated by a set of streets)

sources.sources. Measuring noiseMeasuring noise

The acoustic measure of the intensity of noise is expressed The acoustic measure of the intensity of noise is expressed in decibel (dB).in decibel (dB).

Scale ranging from 1 db to 120 db.Scale ranging from 1 db to 120 db. 0 db is barely perceivable by human beings while 120 db is 0 db is barely perceivable by human beings while 120 db is

considered to be the threshold of pain.considered to be the threshold of pain.

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Noise

The decibel grows on a logarithmic scale.The decibel grows on a logarithmic scale. An increase of 10 db corresponds to an increase in An increase of 10 db corresponds to an increase in

intensity by a factor of 10.intensity by a factor of 10. The acoustic pressure of 120 db is thus one million times The acoustic pressure of 120 db is thus one million times

the one at 0 db.the one at 0 db. Measures are often given in db(A) or in Leq when a time Measures are often given in db(A) or in Leq when a time

period is involved.period is involved. The Leq is the average of noise exposure, often in db (A), The Leq is the average of noise exposure, often in db (A),

over a time period.over a time period. Often measured for the 6h00-22h00 period, which Often measured for the 6h00-22h00 period, which

correspond to the period of the day when most activities are correspond to the period of the day when most activities are performed.performed.

Legal limits usually range between 50 db and 65 db in Legal limits usually range between 50 db and 65 db in OECD countries.OECD countries.

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120

100

0

20

30

40

50

60

70

80

90

110

Desert10

Broadcasting studio

Quiet room

Busy street through closed windows

Busy street through open windows

Noise level near a motorway

Busy crossroads

Lorry, motorcycle, underground train

Pneumatic drill at 1 meter

Aircraft at take off

dB (A)

Noise Levels (in decibels)B-3B-3

Page 53: Topic 3 – Environmental Externalities of Urban Transportation

Noise

Road transportation noiseRoad transportation noise Accounts for about 70% or all noise emitted by transportation.Accounts for about 70% or all noise emitted by transportation. Road transportation modes have different scales of noise Road transportation modes have different scales of noise

emissions. emissions. Main sources of noise come from the engine and the friction of the Main sources of noise come from the engine and the friction of the

wheels over the road surface.wheels over the road surface. One truck moving at 90 km/hr makes as much noise as 28 cars One truck moving at 90 km/hr makes as much noise as 28 cars

moving at the same speed. moving at the same speed. Ambient noiseAmbient noise

Frequent result of road transportation in urban areas.Frequent result of road transportation in urban areas. Addition of all the noise generated by cars, trucks and buses.Addition of all the noise generated by cars, trucks and buses. Permanent ambient noise (ranging from 45 to 65 db).Permanent ambient noise (ranging from 45 to 65 db). Impairs the quality of life in urban areas and thus the property Impairs the quality of life in urban areas and thus the property

values of residences. values of residences. Nearby road arterials, ambient noise is replaced by direct noise and Nearby road arterials, ambient noise is replaced by direct noise and

vibrations.vibrations.

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Noise

The acoustics created by the surrounding environment (hills, The acoustics created by the surrounding environment (hills, buildings, trees, open space, etc.) alleviate or worsen local buildings, trees, open space, etc.) alleviate or worsen local conditions. conditions.

Noise levelNoise level Travel speed and the intensity of traffic are directly linked Travel speed and the intensity of traffic are directly linked

with its intensity of noise.with its intensity of noise. Grows arithmetically with speed.Grows arithmetically with speed. Around 45% of the population in developed countries live in Around 45% of the population in developed countries live in

high levels of noise intensity (over 55 db) generated by road high levels of noise intensity (over 55 db) generated by road transportation.transportation.

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Page 55: Topic 3 – Environmental Externalities of Urban Transportation

Noise Generated by a Passenger Car

0

10

20

30

40

50

60

70

80

90

0 20 40 60 80 100 120Speed (km / hr)

Nois

e (d

B)

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Page 56: Topic 3 – Environmental Externalities of Urban Transportation

~ 80 db(A)

~ 65 db(A)

~ 50 db(A)

100 m

Road Transportation Noise

Ambient noise

Barrier effectSpecific vehicle

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Page 57: Topic 3 – Environmental Externalities of Urban Transportation

Noise

Rail transportation noiseRail transportation noise Accounts for about 10% of all noise emitted by Accounts for about 10% of all noise emitted by

transportation.transportation. Noise comes from the engine (mostly diesel), the friction of Noise comes from the engine (mostly diesel), the friction of

wheels over the rails, and whistle blowing.wheels over the rails, and whistle blowing. Trains moving at high speed, areoacoustic noise becomes Trains moving at high speed, areoacoustic noise becomes

more important than other sources.more important than other sources. Depending of the train aerodynamics, noise emissions Depending of the train aerodynamics, noise emissions

are from 50 to 80 times the logarithm of train speed.are from 50 to 80 times the logarithm of train speed. Become significant at speeds higher than 200 km/hr. Become significant at speeds higher than 200 km/hr.

Convergence of trucks towards railyards provides an Convergence of trucks towards railyards provides an additional source of noise. additional source of noise.

Around 3% of the population may be exposed to high noise Around 3% of the population may be exposed to high noise levels from rail transportation in OECD countries.levels from rail transportation in OECD countries.

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Noise

Level of exposure related to the importance and location of Level of exposure related to the importance and location of rail transportation infrastructure. rail transportation infrastructure.

Important impacts are in urban areas where the majority Important impacts are in urban areas where the majority transshipment functions are performed.transshipment functions are performed.

Rail terminals are often located in the central and high Rail terminals are often located in the central and high density areas of cities. density areas of cities.

~ 70 db(A)

~ 55 db(A)

~ 85 db(A)500 m

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Noise

Air transportation noiseAir transportation noise Accounts for 20% of total noise emissions by transportation.Accounts for 20% of total noise emissions by transportation. Noise emissions have increased significantly to the point of Noise emissions have increased significantly to the point of

becoming a major concern near airports. becoming a major concern near airports. Noise comes from the jet engine, the aerodynamic friction Noise comes from the jet engine, the aerodynamic friction

and ground craft operations.and ground craft operations. The turbofan is the least noisy jet propulsion technology The turbofan is the least noisy jet propulsion technology

available.available. Aircrafts are an acute source of noise in several urban Aircrafts are an acute source of noise in several urban

areas.areas. Noise from aircraft operation is known to have direct impact Noise from aircraft operation is known to have direct impact

on property values around airports.on property values around airports. Heavily used air corridors between major cities creates Heavily used air corridors between major cities creates

noise corridors where ambient noise is almost prevalent.noise corridors where ambient noise is almost prevalent.

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Page 60: Topic 3 – Environmental Externalities of Urban Transportation

Aircraft Takeoff Noise in dB(A)

60 65 70 75 80 85 90 95 100 105

A320

B747-400

B747-100

B777-200

DC10

Can-RJ

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Air Transportation Noise

~ 110 db(A)~ 90 db(A)

~ 60 db(A) 4 km

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Page 62: Topic 3 – Environmental Externalities of Urban Transportation

Global Externalities

1. Greenhouse Effect1. Greenhouse Effect 2. Ozone Depletion2. Ozone Depletion 3. Acid Rain3. Acid Rain

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Greenhouse Effect

ContextContext Not by itself a pollutant.Not by itself a pollutant. Natural process permitting to support life.Natural process permitting to support life.

Without the greenhouse effect, the Earth would be 60o F Without the greenhouse effect, the Earth would be 60o F cooler.cooler.

Combined actions of several greenhouse gases (notably Combined actions of several greenhouse gases (notably carbon dioxide).carbon dioxide).

Transportation accounts for around 30% of total carbon Transportation accounts for around 30% of total carbon dioxide emissions in developed countries (15% worldwide). dioxide emissions in developed countries (15% worldwide).

ProcessProcess The atmosphere is generally permeable to short wave The atmosphere is generally permeable to short wave

radiations.radiations. Those radiations are reflected by the earth surface as Those radiations are reflected by the earth surface as

infrared radiations.infrared radiations. Greenhouse gases absorb and re-emit towards the surface.Greenhouse gases absorb and re-emit towards the surface.

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Greenhouse Effect

Higher capacity of the atmosphere to retain heat.Higher capacity of the atmosphere to retain heat. Indirect consequence of:Indirect consequence of:

Carbon dioxide emissions (about 71% of the Carbon dioxide emissions (about 71% of the contribution).contribution).

CFCs (3%), ozone and methane (8%).CFCs (3%), ozone and methane (8%). ImpactsImpacts

Contributes to global warming.Contributes to global warming. Since 1850, levels of carbon dioxide increased by 25%.Since 1850, levels of carbon dioxide increased by 25%. Average temperature increased by one degree Celsius.Average temperature increased by one degree Celsius. By 2050, an additional rise between 1.5 and 4.5 degrees By 2050, an additional rise between 1.5 and 4.5 degrees

Celsius could occur.Celsius could occur. Ecosystems may be pushed northward.Ecosystems may be pushed northward.

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Average Temperature at the Earth's Surface (Land-based Series), 1866-1999

13

13.2

13.4

13.6

13.8

14

14.2

14.4

14.6

14.8

1866

1872

1878

1884

1890

1896

1902

1908

1914

1920

1926

1932

1938

1944

1950

1956

1962

1968

1974

1980

1986

1992

1998

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Global Average Temperature at Earth's Surface and Atmospheric Concentrations of Carbon Dioxide

300

310

320

330

340

350

360

370Pa

rs p

er m

illio

n

13.6

13.7

13.8

13.9

14

14.1

14.2

14.3

14.4

14.5

14.6

Degr

ees

Celc

ius

Carbon dioxide

Land Temperature

Sea Temperature

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Greenhouse Effect

Rise in sea levels is a potential problem for coastal areas Rise in sea levels is a potential problem for coastal areas where most human activities are located.where most human activities are located.

Rise of 20 cm during the 20th century.Rise of 20 cm during the 20th century. Rise of sea levels, between .5 and 1 meters (2 to 3 feet) by Rise of sea levels, between .5 and 1 meters (2 to 3 feet) by

mid 21st century.mid 21st century. A rise of one meter may flow substantive surface of land. A rise of one meter may flow substantive surface of land.

70% of Bangladesh could be under water.70% of Bangladesh could be under water. 50 cm = 30 million people flooded in the Yangtze delta.50 cm = 30 million people flooded in the Yangtze delta.

May indirectly affects sea current patterns and fishing.May indirectly affects sea current patterns and fishing. Fluctuations in weather systems with changes in regional Fluctuations in weather systems with changes in regional

and seasonal weather patterns.and seasonal weather patterns. Significant effects on the ecosphere, particularly for Significant effects on the ecosphere, particularly for

agriculture.agriculture.

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Greenhouse effect attributed to human activities

71%

1%

2%

1%

18%

7%

CO2

Methane

CFC (R12)

CFC (R11)

NO2

Other

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Share of Global CO2 Emissions, 1996

53%46%

1%

Developed countries

Developing countries

Least developed countries

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Major Contributors to CO2 Emissions (in millions tons), 1996

0 200 400 600 800 1000 1200 1400 1600

United States

China

Russia

Japan

Germany

U.K.

Italy

South Korea

Poland

South Africa

Mexico

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CO2 Emissions by Type of Fuel for the Transportation Sector

66%

16%

15%

3%

Gasoline

Diesel

Jet fuel

Other

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CO2 Emissions by Transportation Mode

43%

20%

14%

14%

7% 2%

Cars

Light Trucks

Heavy Trucks

Airplaines

Rail & Marine

Non oil-based

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Ozone Depletion

ChlorofluorocarbonsChlorofluorocarbons CFCs are colorless and poisonless gases (or liquids).CFCs are colorless and poisonless gases (or liquids). Very stable, non-flammable and non-toxic.Very stable, non-flammable and non-toxic. Have been widely used as dispersing agents (aerosols) or Have been widely used as dispersing agents (aerosols) or

as refrigerants (notably Freon, R-12). as refrigerants (notably Freon, R-12). Motor vehicle air-conditioning systems are the main source Motor vehicle air-conditioning systems are the main source

and account for about 20% of all CFCs emissions.and account for about 20% of all CFCs emissions. During its life cycle, an air-conditioning system will release During its life cycle, an air-conditioning system will release

100% of its CFCs in the atmosphere.100% of its CFCs in the atmosphere. Recent legislations, CFCs emissions have considerably Recent legislations, CFCs emissions have considerably

dropped in developed countries. dropped in developed countries. Because of its chemical properties (stable and non-toxic), Because of its chemical properties (stable and non-toxic),

CFCs have no noticed effects on living organisms.CFCs have no noticed effects on living organisms. Current concentrations of CFCs in the atmosphere reach Current concentrations of CFCs in the atmosphere reach

about 0.35 ppm (all types of CFCs).about 0.35 ppm (all types of CFCs).

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Ozone Depletion

The most widely used type, R12, has 20,000 times more infrared The most widely used type, R12, has 20,000 times more infrared absorbency than carbon dioxide.absorbency than carbon dioxide.

One ton of Freon will have the same greenhouse effect than 2,000 One ton of Freon will have the same greenhouse effect than 2,000 tons of carbon dioxide.tons of carbon dioxide.

CFCs reduce the concentration of stratospheric ozone, which CFCs reduce the concentration of stratospheric ozone, which absorbs harmful ultraviolet rays.absorbs harmful ultraviolet rays.

CFCs may stay in the atmosphere from 70 to 200 years, due to CFCs may stay in the atmosphere from 70 to 200 years, due to their extremely stable properties.their extremely stable properties.

They are a long term component of the atmosphere.They are a long term component of the atmosphere. CFCs emitted in the 1990s are likely to damage the ozone layer CFCs emitted in the 1990s are likely to damage the ozone layer

for 200 years. for 200 years. Indirect effects of CFCs:Indirect effects of CFCs:

Increase in ultraviolet rays exposition.Increase in ultraviolet rays exposition. Growth in the incidence of skin cancer.Growth in the incidence of skin cancer. Eye cataracts.Eye cataracts. Damage to crops and plants.Damage to crops and plants. Deficiencies of the immune system.Deficiencies of the immune system. Increase of ozone at ground levels (through photochemical Increase of ozone at ground levels (through photochemical

smog). smog).

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World Production of CFCs, 1960-1997

0

200

400

600

800

1000

1200

1400

1960

1962

1964

1966

1968

1970

1972

1974

1976

1978

1980

1982

1984

1986

1988

1990

1992

1994

1996

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Acid Rain

DefinitionDefinition Sulfuric acid is a corrosive, oily colorless liquid, which forms Sulfuric acid is a corrosive, oily colorless liquid, which forms

when sulfur oxides and water vapors are mixed.when sulfur oxides and water vapors are mixed. Nitric acid is a corrosive and colorless liquid and forms when Nitric acid is a corrosive and colorless liquid and forms when

nitrogen oxides and water vapor are mixed. nitrogen oxides and water vapor are mixed. Acid formation (sulfuric and nitric) is influenced by the level Acid formation (sulfuric and nitric) is influenced by the level

of exposition to sun light.of exposition to sun light. May also exists in dry form, which is called acid deposition.May also exists in dry form, which is called acid deposition. Dissolution in water:Dissolution in water:

Sulfuric and nitric acids lower the pH (higher Sulfuric and nitric acids lower the pH (higher concentrations of hydrogen ions). concentrations of hydrogen ions).

The standard pH of fresh water ranges between 6.5 and The standard pH of fresh water ranges between 6.5 and 7.5. 7.5.

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Acid Rain

Role of transportationRole of transportation Transportation accounts for 5% of sulfur dioxide emissions.Transportation accounts for 5% of sulfur dioxide emissions. 45% of nitrogen oxides emissions.45% of nitrogen oxides emissions. 40% of HC/HOV emissions.40% of HC/HOV emissions. May range from 10 to 30% of acid rains, depending on May range from 10 to 30% of acid rains, depending on

regions.regions. This figure is of 25% in Western Europe. This figure is of 25% in Western Europe.

ImpactsImpacts Damage structures, such as historical monuments.Damage structures, such as historical monuments. When inhaled as a mist, may cause respiratory organs When inhaled as a mist, may cause respiratory organs

irritation. irritation. Change the chemical composition of soils by breaking down Change the chemical composition of soils by breaking down

complex organic matter in simpler elements. complex organic matter in simpler elements. pH of fresh water alteration. pH of fresh water alteration.

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Acid Rain

Sulfuric and nitric acids are carried over large distances Sulfuric and nitric acids are carried over large distances through weather systems.through weather systems.

It later falls down either as rain or fog.It later falls down either as rain or fog. Alter the ecological balance of continental ecosystems, Alter the ecological balance of continental ecosystems,

notably in industrialized areas.notably in industrialized areas.

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