Revision 3Revision 3

The Amazon RainforestThe Amazon Rainforest

•The dark green areas are all – what?

•What is the pattern of where they are?

•Which is B? BO? C? V? E?

Key idea 1The Amazon is in … and 4 countries that form part of

it are …..

Look at the sun’s rays as they hit Look at the sun’s rays as they hit the Earththe Earth

same width ray, more

spread out –not so hot

same width ray, not spread out at all, much

hotter

Now lets see how the rays pass Now lets see how the rays pass through the atmospherethrough the atmosphere

Look how much thicker

the air is

As the rays from the sun pass through the atmosphere,

some of the heat is reflected back out into space. The thicker the air, the more

heat there is that never reaches

earth

Key Idea 2It is hotter at the equator because the sun’s heat are more spread out/ concentrated and the sun’s

rays travel through more/less atmosphere

Why does it always rain in the Why does it always rain in the Amazon?Amazon?

About 4 o’clock nearly every day

Key Idea 3The sun heats up the warm, damp surfaces. The water turning into

water vapour. Warm air rises, taking the water vapour with it. High up it is colder and the water vapour forms clouds, giving heavy rain.

The Natural Greenhouse Effect at The Natural Greenhouse Effect at workwork

The Earth is covered by a blanket of gas. The energy from the Sun reaches the Earth’s surface, where some it is converted to heat energy.Most of the heat( blue arrows) is re-radiated towards space, but some is trapped by the greenhouse gases in the atmosphere. This natural effect allows the Earth’s temperature to be kept at a level necessary to support life.

The Natural Greenhouse Effect at The Natural Greenhouse Effect at workwork

The main Greenhouse Gas is Carbon Dioxide. Until the last 200 years, the amount of CO2 has remained stable.This is why

Key Idea 4The natural greenhouse effect helps the Earth stay warm/get

hotter. The carbon dioxide/oxygen in the air traps enough of the Sun’s heat to do this. The CO2 stays the same

because animals breath it in/out and plants take it in/out

But then there is the Enhanced But then there is the Enhanced Greenhouse EffectGreenhouse Effect

Look how this is different!Much more of the heat from the sun gets trapped in the atmosphereSo the Earth gets hotter

Why is more heat getting trapped?Why is more heat getting trapped?

We are taking the stored carbon from the ground (oil and coal and gas) and burning itThis releases the CO2 and so the main greenhouse gas is increasing

Where does the rain forest come Where does the rain forest come into this?into this?

The only way carbon dioxide can be taken out of the atmosphere is by the plants – and trees are better at it than most because they are bigger and need to make more sugar to grow. Without our forests, less

of the carbon dioxide would taken out of the air, so more of it would be left to trap more heat from the sun.

So this is why the rainforests matter

to the Earth

So these are the things that can So these are the things that can happen if we increase the amount of happen if we increase the amount of

greenhouses gasesgreenhouses gases

Some places will be

wetter

colder

drierWindier

Hotter

Key Idea 5The enhanced greenhouse effect helps the Earth stay warm/get

hotter. The CO2 stays the same/increases because we are burning fossil fuels and/or cutting down the trees

If we cut down trees the forests will If we cut down trees the forests will suffer as wellsuffer as well

Before: moist, shaded, with lots of leaves to make compost

After: dry and desiccated as the sun dries up the soil and makes it cracked – the compost blows away

The soil

The temperatureThe temperature

Before: the temperature is kept down in the day because of the shade, but the trees act as a blanket making it only a bit cooler at night

After: Very hot in the day but cools quickly at night with no protective trees

VegetationVegetation

Before: Lots of thing grew

After: With poor soil and the water evaporated, it would turn into a desert eventually

Greenhouses gasesGreenhouses gases

Before: As much as 10% may be trapped

After: None is taken in. But worse still even more can be released, by burning or rotting

Flooding and droughtFlooding and drought

Before: Heavy rain hits the tree-tops and drips down through the branches, runs down the trunks and soaks into the soft earth

After: The heavy rain hits the baked earth hard, forming puddles and floods. The earth has been baked by the sun so it floods and then runs off into the river, taking any loose soil with it – this is called soil erosion

Key Idea 6Key Idea 6

Can you think of 3 ways Can you think of 3 ways the forest suffers when the forest suffers when the trees are cut down?the trees are cut down?

HintsHints

Soil, temperature, Soil, temperature, vegetation, greenhouse vegetation, greenhouse gases, flood and droughtgases, flood and drought

What are the main causes of What are the main causes of deforestation?deforestation?

So what could they do instead?So what could they do instead?

We looked for sustainable activities – activities that do not use up or destroy what is thereButterfly farms – can you remember how that worked?Harvesting and growing forest fruits – acai and guarana, brazil nuts, vanillaAgroforestry – what is that? Why is it a good thing?Natura beauty products - fair trade invests in the community and saves the environmentEco-tourism that saves the things people want to see – is run by the people who live there and improved their quality of life

The last two key The last two key ideasideas

Key Idea 7Key Idea 7

Can you think of 3 of the main Can you think of 3 of the main reasons why the rainforest is being reasons why the rainforest is being

cut down?cut down?

Key Idea 8Key Idea 8

Could you write a short paragraph Could you write a short paragraph explaining about one scheme/project explaining about one scheme/project

that is using the rainforest in a that is using the rainforest in a sustainable way?sustainable way?