Part 6-Lesson 1

PART 6-LESSON 1The result of the Industrial Revolution on the atmosphere and hydrosphere

INTRODUCTION The worlds population started to explode in

the 1850’s. Ever since we have been trying to make the world a more hospitable place. A result, natural habitats have become less hospitable. Our comforts have come at a great cost to the environment.

INTRODUCTION The regions most affected are the

hydrosphere and atmosphere. Since the Industrial Revolution (IR) we have built huge cities all over the world whose large power demands must be met. The main way we have achieved this is through the burning of fossil fuels.

GREENHOUSE GASES The burning of fossil fuels release energy and

gases into the atmosphere which affect the chemical and physical properties of other atmospheric gases. We call these greenhouse gases. Carbon Dioxide Water Vapour Methane Fluorocarbons Nitrous oxide

GREENHOUSE GASES Greenhouse gases are transparent to

particular types of radiation allowing some types to pass through them while absorbing others and preventing them from passing through

GREENHOUSE GASES This property of

selective absorption of radiation is responsible for creating what is known as the greenhouse effect. The greenhouse effect is enhanced by increasing levels of greenhouse gases in the atmosphere.

GREENHOUSE GASES All 5 of the above compounds are referred to

as greenhouse gases because of their ability to selectively absorb infrared radiation from the Earth and allow radiation from the sun to pass through. The table below shows the relative proportions of the main types of greenhouse gases (excluding water vapour)

Gas Percentage %Carbon Dioxide 57Fluorocarbons 25Methane 12Nitrous Oxide 6

GREENHOUSE GASES The table below shows the warming potential

for each of the gases listed. Notice CFC’s can have over 7000 times the warming potential of carbon dioxide.

Gas Warming potential (compared to carbon dioxide

Carbon Dioxide 1Fluorocarbons 3400-7100Methane 26Nitrous Oxide 270

GREENHOUSE GASES According to the table it may appear as

though Carbon Dioxide plays an insignificant role in the greenhouse effect. However, due to the large quantities present compared to the other gases, it plays a major contributing factor in producing the greenhouse effect.

THE PRODUCTION OF GREENHOUSE GASES Water vapour originates from one of the

two following processes: Evaporation of water from natural water storages A by-product of industrial processes

The combustion of coal is a process responsible for emitting water vapour into the atmosphere. Coal is responsible for producing 77% of the electricity in Australia.

THE PRODUCTION OF GREENHOUSE GASES Over 80% of the Carbon Dioxide emissions

is due to the burning of fossil fuels. Most of the remaining 20% is made up from the burning of forests that have been cleared.

The concentration of carbon dioxide is currently rising. Evidence from ice core samples suggests that before the Industrial Revolution in the 50’s and for 10,000 years prior, carbon dioxide levels were 270ppm (parts per million). Currently the level is 350ppm and rising.

THE PRODUCTION OF GREENHOUSE GASES The chart below shows by region, the carbon

dioxide emitted per capita.

Region Carbon dioxide emitted per capita

North America 15.4Australia/Oceania 11.0Central and Western Europe

8.4

Asia 1.7Latin America 1.7Africa 1.0

THE PRODUCTION OF GREENHOUSE GASES Most of our fuels contain carbon as they were

formed by the decay of living material. The products produced from the burning of these fuels are primarily carbon monoxide, carbon dioxide, and water vapour.

Not only does the burning of coal add water vapour to the air, it also adds high amounts of carbon. The carbon released by burning coal reacts with oxygen to produce carbon dioxide.

THE PRODUCTION OF GREENHOUSE GASES The combustion of octane in petrol in an

automobile also adds significantly to the atmospheric carbon dioxide levels.

THE PRODUCTION OF GREENHOUSE GASES Methane makes up about 95% of natural

gas composition. Before the IR methane levels were about 750ppm. Today they are close to 1650ppm. The rate is increasing about 1% each year. Sources of methane emissions include the following processes: Naturally produced in swamps as a result of the

breakdown of organic material Fermentation of grass in the stomach of animals

(50%) Anaerobic decay in rice paddies (35%) Emissions from mining and drilling programs

(15%)

THE PRODUCTION OF GREENHOUSE GASES In Australia, cows and sheep are responsible

for about 90% of methane emissions. This is about 3 million tonnes every year!

Other processes that produce methane include the decomposition of livestock manure and the decomposition of landfill material. This methane produced in landfills has proved to

be a usable resource. In Melbourne methane produced from decaying rubbish is being used to generate electricity.

THE PRODUCTION OF GREENHOUSE GASES Natural formation of nitrous oxide occurs

through the action of certain bacteria on nitrogenous material in soils. Prior to the IR atmospheric levels of nitrous oxide were 285ppb. Today levels are about 305ppb.

THE PRODUCTION OF GREENHOUSE GASES Human activity has increased the release of

nitrogen into the atmosphere through increased use of nitrogenous fertiliser. Nitrous oxide is also produced in automobile engines.

THE PRODUCTION OF GREENHOUSE GASES Fluorocarbons are gases containing

chlorine compounds made by humans. Prior to 1850 the atmosphere contained no fluorocarbons. The levels in 1990 were .00025. Increasing at a rate of 4% each year.

THE PRODUCTION OF GREENHOUSE GASES Fluorocarbons were largely used as

refrigerant in air conditioners and refrigerators, as propellants in aerosol spray cans and as solvents. Currently across the world these gases are being phased out.

HOMEWORK

Read pages 145-146 HSC Spotlight TextUpdate electronic vocabulary

PART 6-LESSON 2The result of the Industrial Revolution on the atmosphere and hydrosphere

THE PRODUCTION AND EFFECTS OF ACID RAIN Acid rain is produced primarily by the release

of sulfur oxides and nitrogen oxides into the atmosphere. These oxides are emitted from electrical generating plants, industrial boilers and large smelters where fossil fuels are burnt in large amounts.

THE PRODUCTION AND EFFECTS OF ACID RAIN The countryside around Queenstown in

Tasmania has been described as a moonscape because of the lack of vegetation. This vegetation was killed off by the action of acid rain which resulted from mining operations in the area.

THE PRODUCTION AND EFFECTS OF ACID RAIN For environmental reasons mining in this

area has been stopped and vegetation is slowly returning to the area.

THE PRODUCTION AND EFFECTS OF ACID RAIN Acid rain can have

very serious effects on the environment. Soils become acidic, leaves of plants are burnt, waterways become acidic and injure or kill aquatic life, humans can be affected and building made of limestone or marble become corroded.

ACTIVITY Complete DOT Point 6.1 and 6.4 together

HOMEWORKComplete DOT Points 6.3 and 6.7

PART 6-LESSON 3The result of the Industrial Revolution on the atmosphere and hydrosphere

GLOBAL WARMING Global warming refers to an increase in the

Earth’s temperature due to such things as burning fossil fuels, industrial processes and agricultural processes which build up greenhouse gases in the atmosphere. This phenomenon is a highly debated issue.

GLOBAL WARMING There has been much emphasis in recent

times on the cause of global warming. Three viewpoints stand out: Global warming is enhanced by human activity Global warming is a natural fluctuating process Global warming is a false phenomena created by

poor measurement and analysis of statistics

What do you think?

GLOBAL WARMING Greenhouse gases normally surround the

Earth keeping it 33 degrees warmer than if they were not present. This natural greenhouse effect is what enables life to survive on Earth.

GLOBAL WARMING It’s believed that natural processes such as

weathering, volcanic activity, respiration, photosynthesis and decomposition produce just enough of these gases to enable our planet to support life.

GLOBAL WARMING The increased burning of fossil fuels and wide

spread deforestation have caused greenhouse gases to dramatically build up in the atmosphere.

GLOBAL WARMING Since 1850 there has been a mean rise in

global temperature of approximately 1 degree Celsius and a 28% rise in carbon dioxide levels.

GLOBAL WARMING Due to the greenhouse effect of carbon

dioxide, many scientists link the rise in global temperature to the increase in carbon dioxide levels.

GLOBAL WARMING If this is a real phenomenon, predictions of

what the future might be like are daunting:

Higher global temperatures changing climates Rainfall patterns would alter affecting agriculture Patterns of drought and floods would be

disrupted Ice caps would melt Sea levels would rise Heat related health problems would increase Hotter climates would encourage the spread of

disease

GLOBAL WARMING Some scientists believe that global warming

is a natural process that happens between ice ages resulting from the following geological events:

Volcanic outgassing (if large amounts of volcanic activity were to occur it could change global temperatures dramatically

Plate convergence producing mountains which would increase the rate of weathering releasing large quantities of carbon dioxide into the atmosphere from the chemical breakdown of minerals

GLOBAL WARMING Other scientists believe the greenhouse

effect is statistically false. A skewed interpretation of data.

The debate remains as to what is causing global warming. What do you think?

HOMEWORK

Read pages 148-150 HSC Spotlight TextUpdate Electronic vocabularyComplete DOT Point 6.2 pg 73

PART 6-LESSON 4The result of the Industrial Revolution on the atmosphere and hydrosphere

WHAT IS BEING DONE TO STOP GLOBAL WARMING? Increased global temperatures has prompted

government agencies and industry both nationally and internationally to protect the environment; specifically the atmosphere and hydrosphere.

WHAT IS BEING DONE TO STOP GLOBAL WARMING? Most people believe it is possible to make a significant difference to our environment and that we can all be involved in its improvement.

So what’s being done?

WHAT IS BEING DONE TO STOP GLOBAL WARMING? To say that nations should stop emissions

altogether would be unrealistic. However emissions cannot continue at the present rate for reasons we’ve already discussed.

This makes it very difficult to determine by how much emissions can be reduced without having a negative economic growth for each individual nation

ACTIVITY Read pages 150-151 HSC Spotlight Text

Together and complete activity 3.12 on page 151

HOMEWORK

Read pages 150-151 HSC Spotlight TextUpdate electronic vocabularyComplete ‘To Think About’ pg 152-154 HSC Spotlight TextComplete DOT Point 6.8.2

PART 6-LESSON 5The result of the Industrial Revolution on the atmosphere and hydrosphere

OZONE DEPLETION The atmosphere is a protective layer around

the Earth. We have discussed how easily greenhouse gasses can disrupt the balance within this layer. In this section we are going to look at another group of chemicals and how they have been eating away at a specific part of the atmosphere called the ozone layer.

OZONE DEPLETION The ozone layer acts as a protective barrier

against ultraviolet radiation. It blocks out approximately 95-99% of these harmful rays from the sun. We learned about this layer previously and how important it was to evolution.

OZONE DEPLETION Ozone consists of 3 atoms of oxygen and

collects in the stratosphere. It is constantly being made because of interactions with incoming ultraviolet radiation.

OZONE DEPLETION Certain chemicals easily break down this

molecule. The main offenders are CFC’s which we discussed earlier as a greenhouse gas.

OZONE DEPLETION CFC’s are very stable and

can remain in the atmosphere for up to 75 years. When they finally break down they are very active. When CFC’s break up they form chlorine radicals

(–Cl). These chlorine radicals are then able to react with ozone and convert it back into normal oxygen. Resulting in less ozone to protect us.

OZONE DEPLETION CFC’s originate in cities all over the world

however they are transported to the poles because of the Earth’s rotation and wind patterns. The ozone-depletion reaction also occurs at a higher rate in colder temperatures.

OZONE DEPLETION As a result there is a hole in the ozone layer

above Antarctica. Satellite imagery has enabled scientists to monitor this hole. Evidence from images along with surface monitoring of ultraviolet radiation suggest that ozone is depleting.

OZONE DEPLETION This evidence has forced governments to do

something. In 1987 a treaty known as the Montreal Protocol was signed with the aim of saving the ozone layer.

OZONE DEPLETION The Montreal Protocol called for the cutback

in the production of ozone depleting chemicals by 50% by the year 2000.

OZONE DEPLETION This treaty has been revised twice and now

states that CFC’s would not be produced after 1995 and that other halocarbons would be controlled until 2030.

It’s hoped that this will lead to the recovery of the ozone layer by 2050 however because CFC’s do not break down quickly may take much longer to notice any changes.

OZONE DEPLETION As discussed earlier, the Kyoto Protocol

commits 38 countries to cutting greenhouse gases back to 5.2% below the 1990 levels by 2012.

The Montreal Protocol reduced the production of CFC’s however replaced their use with HFC’s which are a greenhouse gas…. So there are still issues that need to be sorted out.

OZONE DEPLETION Australia has played a critical role in

monitoring and research in regards to ozone depletion.

Why do you think this is so?

HOMEWORKComplete ‘Activity 3.13’ pg 156 HSC Spotlight TextComplete DOT Point 6.7-6.8