Greenhouse Effect

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Greenhouse Effect

It seems like everyone blames bad weather on the greenhouse effect. But...

The greenhouse effect is where the temperature of the Earth increases. This happens as less heat is radiated back from the Earth than is received from the Sun.

The atmosphere becomes clogged up with "greenhouse gases" such as carbon dioxide from burning fossil fuels and methane. This lets the heat from the Sun in but stops some of it from be radiated back out again.

greenhouse gases

This is just how the glass on a greenhouse works. So the inside of the greenhouse gets warmer and warmer over time.

In the case of the Earth the warming up has happened very slowly over decades and centuries. However the levels of greenhouse gases have risen sharply recently.

As the temperature of the Earth increases it is predicted that we will see changes in weather patterns, including drought and flooding.

The Polar ice caps may melt and so produce raised sea levels. Low-lying areas will be flooded including many major cities.

Carbon dioxide and methane are thought to be "greenhouse gases". But how are they produced?

Carbon dioxide

Normally there is a balance in the amount of carbon dioxide in the atmosphere. It is produced by respiration and used up in photosynthesis. So across the whole planet there is a beautiful balance as part of the "carbon cycle".

carbon cycle

However, as we have cut down trees for farming land, fuel and timber we reduce the number of plants that can carry out photosynthesis. This 'deforestation' results in less carbon dioxide being cleared from the atmosphere.

At the same time we have burned a huge amount of fossil fuels in the last two centuries, ever since the start of the 'industrial revolution'.

All this burning results in even more carbon dioxide being produced. Levels have risen by about 20% already and are still increasing - and doing so even more quickly!

carbon dioxide levels

More carbon dioxide is being produced and less cleared away.

We are slowly suffocating ourselves!

Methane

The other common greenhouse gas is methane. Its molecules have one carbon and four hydrogen atoms.

Marshland and bogs produce methane naturally. It bubbles up from decaying plant material.

However, increasing amounts are produced through agriculture. The two main ways are in rice production (paddy fields) and cattle rearing. It seems that cows pass wind each day, just like us, but in greater volume.

Anyone want to volunteer to find out how many litres a cow farts each day?

No, I thought not.

S-cool exclusive!!