Acid Rain- Global Warming

7/29/2019 Acid Rain- Global Warming

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OUP: To be used solely in purchasers school or college

AIR

WHAT IS IT MADE

OF?


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Composition of air


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http://www.bbc.co.uk/schools/gcsebitesize/science/aqa_pre_2011/oils/changesrev5.shtml


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What is global warming?

Over the last few hundred

years, the average

temperature of the Earths

oceans has been rising.

This is global warming.

Why is this a problem?

Global warming increases the

energy in the atmosphere, makingit turbulent more storms, more

droughts, more floods.


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The greenhouse effect is a theory to explain whyglobal warming is happening.

What about the greenhouse effect?

The world needs the greenhouse effect. Without it the

Earth would be too cold for most organisms to live.

How does the greenhouse effect explain global warming?

In the atmosphere

is a layer of

greenhouse

gases.

Light reaches us from the

Sun. Some of it is absorbed

by the Earth and warms it.

Some is reflected back into

space.

The Earth gives off infrared

radiation because it has

been warmed by the Sun.

With more greenhouse

gases, more infrared is

reflected back to the Earth,

and it gets warmer still.

Some infrared radiation is

reflected back by the

greenhouse gases. Thismakes the Earth warmer

than it would be without

the greenhouse gases.


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The key greenhouse gases

Do these gases act as greenhouse gases in the

atmosphere? Answeryes orno.

One of these gases in particular is on the rise, causing the

enhanced greenhouse effect. Which gas?

What processes produce this gas?

A greenhousegas is a gas in the atmosphere that reflectsinfraredradiation back to Earth.

gas source greenhouse gas?carbon dioxide Burning of fossil fuels

methane Cattle farmingCFCs Industry

ozone Car exhaustsnitrogen and

sulpher oxides

Incomplete combustion

of hydrocarbons

yes

yes

yes

yes

yes


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Acid rain



What is acid rain?

Rain is naturally slightly acidic. Why?

Because carbondioxide in the air dissolves in the fallingwater to make carbonicacid.

carbon dioxide+water carbonic acid

So whats acidrain?

Its a term used for rain that

is more acidic than normal.

Acid rain forms when acidic gasesin the airdissolve in the rain.These gases come from burning

fossilfuels.

normal rain acid rain



Acid rain is more acidic than normal

rain. But how does it compare with

other acids?

How acidic is acid rain?

Match the pH to the substance.

pH 1 pH 2pH 3 pH 4pH 6 pH 7

substance pH

unpolluted raincar battery acidacid rain from a polluted area

acid in your stomachpure watervinegar

pH 6pH 2

pH 4

pH 1pH 7

pH 3



transport (cars, planes, trains, etc.)

domestic (fires at home)

generating electricity

industrial furnaces and boilers

forest fires, volcanoes and other natural sources

What causes acid rain?

All of these processes produce acidic gases whichcause acid rain.

Rank them in order, starting with the worst offender.

1. generating electricity2. transport (cars, planes, trains, etc.)

3. industrial furnaces and boilers4. forest fires, volcanoes and other natural sources5. domestic (fires at home)



Meet the acid gases

The main acidic gases are:

sulphur dioxide (SO2) nitrogen oxides (N2O, NO, NO2)

Acidic gases in the air can cause lung problems.

Roughly how manyextra deaths occurred

from the 5th to the 9th

of December?

Is it fair to say that acid

gases caused these

deaths?

deaths per day

sulphur dioxide

concentration

date, December 1952

deaths

per

day/sulphurdioxide

(ppb)



How is acid rain formed?

Acid rain can fall many miles from the source of the pollution.

What problems does acid rain cause?

Burning fuels release acidic

gases, mainly sulphur

dioxide (power stations) and

oxides of nitrogen (vehicles).

Acid gases rise in

the air.

Acid gases react together

in the clouds sunlight

encourages this reaction.

Dry deposition acid

particles fall to the

ground in dust.

Falling rain

dissolves the

acidic gases.

Acid rain falls to

the ground. It

makes soil, lakesand rivers more

acidic.



STARTER

Complete the Percentage Composition of Air

exercise



It takes a while...

But acid rain is dangerous because it acts over many

years.

And because the changes from day to day are small,people do not notice them.

Why does this make it even more dangerous?

Acid rain is a dilute acid solution.

The acid in your stomach isstronger and more corrosive.

Think how much rain falls on a building over 200 years!

Even a slight increase in the acidity of rain could haveserious effects over this timescale.



But the effects are serious

Acid rain reacts to dissolve

away rockssuch aslimestone. This destroys

valuable buildings.

It makes rivers and lakes more acidic.This causes problems on moors and

mountains where the ground is already acidic.

It allows poisonous chemicals such as

aluminium saltsto dissolve in water and soil.They poison trees and fish.

It reduces the growth of plants, including food crops.

H h ?



Is pollution getting worse or better?

Hope or horror?

3719 64601188 875

4854

Try to match the year to the

amount of acidic gas produced.

Weve added a guess for 2012.

If you drew a graph of this data, what would it look like?

Can you explain this trend?

year thousand tonnes of SO2produced in UK

1970

1980

1990

2000

2012

6460

4854

3719

1188

875

G d b d



Good news, bad news

So is the pollution problem getting better?

Decide whether each headline is

good news orbad news.

Levels of acidic

gases in the

atmosphere arefalling.

We are

using cars

more andmore.

Governments all over

the world have agreed

to cut emissions ofacidic gases.

Modern devices

are more energy-

efficient than oldones.

We are developing

more and more

gadgets and devicesthat use energy.

What do you think? How could we do better?

Q i



1. Sulphur dioxide is an acidic gas made by...

a) burning scrap metal

b) burning fossil fuels

c) cows as they digest grass.2.Acid rain is caused by...

a) acidic gases in the atmosphere dissolving in falling

rainb) ozone in the atmosphere dissolving in falling rain

c) increased sunlight.

Quiz

Q i



3. The best way to reduce acid rain is by...

a) releasing alkaline gases into the air

b) pushing rain clouds out to sea with jet engines

c) reducing the production of acidic gases.4. Which of the following is NOT caused by acid rain?

a) damage to buildings made of limestone

b) damage to lakes in some highland areas

c) asthma.

Quiz

T f l ?


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1. Carbon dioxide contributes significantly to thegreenhouse effect.

2.Plants tend to increase the greenhouse effect bygiving out carbon dioxide.

3. The rise in carbon dioxide in the atmosphere isprobably due to human activity.

4. Global warming is causing a hole in the ozone layer.

True or False?

True or false?

Yes, most scientists agree with this statement.TRUE! Plants take in carbon dioxide during the day forphotosynthesis, so they tend to reduce thegreenhouse effect!

FALSE! Again, most scientists now accept thisstatement.

TRUE! CFCs are causing the hole in the ozone layer,which is letting more ultraviolet radiation reach

us. This is not the same problem as global

warming.

FALSE!

Acid Rain- Global Warming

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