Prior learning –There are 3 kinds of rock – sedimentary, metamorphic and Igneous –Igneous...

• Prior learning– There are 3 kinds of rock – sedimentary, metamorphic and Igneous– Igneous rocks form crystals depending on the length of time it

takes them to cool down- Theory of continental drift- Rock cycle

• Key words– Photosynthesis, respiration, decomposition, decomposers, decay,

carbon, cycle, fossil fuels, combustion, greenhouse effect, climate change,

Unit 11 – Science and HumanityOctober

Title: Task 5: Changes that occur during the carbon cycle and the effects on climate

change.

IAM LEARNING:Describe the long-term changes that have occurred in

our universe to our solar system and earth

I WILL BE SUCCESSFUL IS I CAN:• Identify the changes of the carbon cycle• Understand what the combustion of fossil fuels are• Explain the greenhouse effect• Explain the theory behind climate change

I CAN:• Complete the stages in the carbon cycle• Explain how the combustion of fossil fuels impacts

on the carbon cycle and how this in turn impacts on the greenhouse effect

• Explain the link between climate change and fuel consumption and identify any governmental measures that are or are planned to be put in place to reduce the effects

Unit 11 – Science and Humanity

• I’m a viscous semi-solid withconvection currents circulating in me.

• I’m iron and nickel too, but I’m liquid.

• I just hang around on the outside.

• I’m really very thin and am mostlysilicon, oxygen and aluminium.

• I am dense, very hot, made mostly ofsolid iron and nickel.

Inner core

Outer core

Atmosphere

Crust

Mantle

STARTER: What am I?


• The Earth was formed about 4,500 million years ago.

• During the first billion years there was intense volcanic activity, which produced the early atmosphere. This would have contained large quantities of carbon dioxide (CO2) and water vapour. Methane (CH4) and ammonia (NH3) are thought to have also been present.

• This is rather like the atmosphere on Mars and Venus today.

• The water vapour condensed to form the oceans.

Mars

Venus

The early atmosphere


• Carbon dioxide reacted with rocks and much became trapped in them.

• The evolution of algae some 3,000 million years ago, and subsequently plants which successfully colonized the Earth’s surface, led us towards the present atmosphere.

• Their photosynthesis replaced carbon dioxide with oxygen.

• Over a period of time, billions of tonnes of carbon dioxide became locked up in fossil fuels.

Earth

Photosynthesis increased

oxygen levels

Oxygen levels increase


• As oxygen levels rose, atmospheric ammonia (NH3) reacted with oxygen(O2) to form water (H2O) and nitrogen (N2).

• Also, living organisms, including denitrifying bacteria, broke down nitrogen compounds releasing more nitrogen into the atmosphere.

• And so the atmosphere headed towards a composition that has remained fairly constant for the last 200 million years.

Nitrogen appears

78%

21% 1%

Nitrogen

Oxygen

Other


Copy the timeline and arrange the blue boxes in appropriate places along the line.

4,500 million

Now3,000 million

2,000 million

1,000 million

500 million

200 million

No gases

H2 and He

CO2 NH3 CH4

H2O N2 O2

Volcanoes

Algae

Plants

Atmosphere timeline


All positions are approximate

4,500 million

Now3,000 million

2,000 million

1,000 million

500 million

200 million

No gases

H2 and He

Volcanoes Algae Plants

CO2 NH3 CH4

O2 N2 H2O

Atmosphere Timeline


Use the graph to estimate the answers.

1. How long ago was the atmosphere 75% CO2?

2. How long ago were the CO2 and N2 levels in the atmosphere equal?

3. How long ago was the atmosphere 50% nitrogen?

carbondioxide

nitrogen

oxygen

100%

50%

0%5,000 3,000 0

Com

posi

tion

perc

enta

ge

Time (millions of years)

now

Approx 4,000M

Approx 3,300M

Approx 2,000M

PLENARY: Changing gas levels


IAM LEARNING:Describe the long-term changes that have occurred in

our universe to our solar system and earth

I WILL BE SUCCESSFUL IS I CAN:• Identify the changes of the carbon cycle• Understand what the combustion of fossil fuels are• Explain the greenhouse effect• Explain the theory behind climate change

I CAN:• Complete the stages in the carbon cycle• Explain how the combustion of fossil fuels impacts

on the carbon cycle and how this in turn impacts on the greenhouse effect

• Explain the link between climate change and fuel consumption and identify any governmental measures that are or are planned to be put in place to reduce the effects


• Oxygen normally exists as pairs of atoms (O2).

• Oxygen can, however, turn into another form that has three atoms joined together. This is ozone (O3).

• As oxygen levels rose, so did the amount of ozone.

• This layer of ozone in the atmosphere filters out harmful ultraviolet rays from the sun. This will have allowed new organisms to evolve and survive.

3O2 2O3

oxygen ozone

Earth

Harmful UV rays stopped

with ozone layer

Harmful UV rays reach Earth’s surface

without ozone layer

Ozone: a vital filter


The carbon cycle


CO2 release or consumption?


Over millions of years the carbon cycle has maintained a constant, low percentage (approx. 0.03%) of carbon dioxide in the atmosphere.

In 1860, the CO2 level was about 289 ppm (parts per million).

Here is a table showing the CO2 levels over a recent 10-year period.

Year

Carbon dioxide (ppm)

1979 333.681980 335.551981 337.141982 338.381983 340.251984 341.821985 343.181986 344.261987 345.991988 347.96

What percentage change is this and does it matter?

Carbon dioxide and temperature


From air trapped in Antarctic ice, we have a good idea of CO2

concentrations going back 160,000 years.

Which label goes with each picture?

200ppmCO2

300ppmCO2

We also know the temperatures over the same period.

The very warm interglacial period of 130,000 years ago was accompanied by CO2 levels of around 300 ppm.

The previous great Ice Age had CO2 levels around 200 ppm.

Changing CO2 concentrations


Normally the Earth absorbs heat and emits heat at the same rate. Because of this the temperature remains constant.

Certain gases, like CO2 and methane, act like a greenhouse. They let heat in but do not let it out. This is called the greenhouse effect.

This means that the more CO2 there is, the hotter planet Earth is!

Earth

Heat from sun

Heat loss

More CO2

Earth

Heat from sun

Heat loss

hotterAnd hotterAnd hotter!

balanced same temp

The greenhouse effect


Work through Task 5: Effect on Climate Change using the

information you have gathered in the past

lessons


Prior learning –There are 3 kinds of rock – sedimentary, metamorphic and Igneous –Igneous...

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