My Science School

Earth’s climate is slowly getting warmer. Scientists who study the climate have found that it is a little warmer now than it was 100 years ago. You may not notice the difference, but plants and animals do.

Is it true? Trees reduce carbon dioxide in the atmosphere.

Yes. Tree leaves take harmful carbon dioxide from the atmosphere and give out oxygen. We breathe the oxygen they make.

Why is the temperature rising?

It’s getting warmer because of what the Earth’s 6 billion people are doing. Because of the way we lead our lives; we are changing the Earth’s climate. We are making the planet grow warmer.

Amazing! There is far more carbon dioxide in the atmosphere than there was 200 years ago. This is mainly why it’s warmer today than it was in the past.

How are we making the temperature rise?

By burning ‘fossil fuels’ — coal, oil and natural gas — we are putting ‘greenhouse gases’, such as carbon dioxide, into the atmosphere. The gases surround the Earth and keep heat in.

Picture Credit : Google

As the Earth’s climate warms up, glaciers and the ice at the North and South Poles will melt, causing the sea level to rise. This will bring floods, and some islands will disappear. Deserts will spread, and droughts will occur.

Amazing! Cows are making the temperature rise. The smelly greenhouse gas methane comes from animals, such as cows, and from factories. Humans make it, too!

How can governments reduce carbon dioxide levels?

Burning petrol in cars puts carbon dioxide into the atmosphere. Governments can build transport systems that don’t make carbon dioxide, and order more trees to be planted.

What can I do to help?

Use less electricity. This is because most electricity comes from burning fossil fuels which makes carbon dioxide. Switch off lights, TVs and computers when not in use.

Is it true? If the Antarctic ice sheet melted, the sea level would rise.

Yes. It holds two-thirds of the Earth’s fresh water. If it melted, the sea would rise by up to 70 metres. Coastlines would change all over the world.

Picture Credit : Google

Look at Earth from space and you see a mainly blue, watery planet with swirling white clouds. All looks well, but get closer, and you see a different picture. Parts of Earth are unhealthy — and all because of the way we live.

Does Earth need looking after?

Earth is our only home - we can’t live on other planets. We need to look after it to make sure it stays a beautiful, healthy place. If we don’t care for the Earth now, we will spoil it for the people of the future.

Can I help care for the Earth?

There are many things you can do in your everyday life to care for the Earth. This book tells you about some of them. Just think, if everyone did the same as you, Earth would be a better place to live.

Is it true? There is no other planet like Earth.

Yes. There is only one Earth. It is special - it is the only planet known to have life on it. Perhaps one day life will be found on another planet, too.

Amazing! There has been life on Earth for approximately 3.5 billion years.

Picture Credit : Google

Volcanoes are mountains that spit fire. Deep under the Earth there is red-hot, runny rock called magma. Sometimes the magma bursts up through a crack in the Earth’s crust and a volcano erupts.

Amazing! Some of the world’s highest mountains are volcanoes. They include Mt Kilimanjaro in Africa. Luckily for this nosy lion, Kilimanjaro is now long extinct.

What is lava?

Once magma has erupted from a volcano, it is called lava. Some lava is thick and lumpy. Some is thin and runny. In the air, it cools and turns into hard, black rock.

Is it true? Volcanic ash can flow as fast as a train.

Yes. Clouds of gas and ash can flow across the ground at over 160 kph!

What happened to Pompeii?

In AD 79, Mt Vesuvius in Italy blew its top in a massive explosion. The nearby city of Pompeii was buried under a huge cloud of hot ash and rock. Thousands of people were suffocated. Others fled for their lives.

Picture Credit : Google

The Earth’s surface is cracked into enormous pieces which drift on the red-hot, runny rock below. Sometimes two pieces push and shove each other, making the Earth shake.

How much damage do earthquakes cause?

Big earthquakes do lots of damage. Huge cracks open up in the ground. Houses, roads and bridges shake and fall down. In the worst earthquakes, many people are killed and injured by buildings that collapse on them.

How do scientists measure an earthquake?

An earthquake sends shock waves rippling through the ground. Scientists study these waves to see how big the earthquake is. They measure earthquakes on a scale of 1 to 10. Each quake on the scale is 30 times worse than the one before.

Is it true? People used to think earthquakes were caused by fish.

Yes. In Japan, people thought quakes were caused by a giant catfish wriggling about on the sea bed. The gods had to put a rock on the fish’s head to make it stay still!

Picture Credit : Google

The Earth is shaped like a gigantic ball, slightly squashed at the top and bottom. Around its middle, where it’s fattest, it measures 40,075 kilometres. It would take you almost a year to walk right round the Earth, without a rest.

What are the continents?

The Earth’s rocky crust is cracked into several gigantic pieces and lots of smaller chunks. The large pieces contain the seven continents - Africa, Antarctica, Asia, Australasia, Europe, North America and South America. Which of the continents do you live on?

What’s inside the Earth?

The Earth is made up of layers of rock and metal. We live on the hard, rocky surface, called the crust. Below, the layers are so hot that they’ve melted and turned runny. The centre of the Earth is a ball of almost solid metal.

Amazing! People used to think the Earth was flat. If they sailed too far in one direction, they thought they would fall off the edge!

The North and South Poles are at either end of the Earth. The North Pole is surrounded by the frozen Arctic Ocean. The South Pole is in the middle of icy Antarctica.

Amazing! The coldest place on Earth is Vostok in Antarctica. Here temperatures can plummet to an f-f-freezing minus 89°C.

Why are the Poles cold?

The Poles are the coldest places on Earth. They’re battered by blizzards and covered in ice and snow. The Poles are cold because the Sun’s rays hit them at a slant, so they’re spread out and very weak.

Is it true? Penguins live at the North Pole.

No. Penguins only live around the South Pole. But you might bump into a polar bear at the North Pole.

Who reached the South Pole first?

The first person to reach the South Pole was Norwegian explorer Roald Amundsen in December 1911. He beat the British team of Captain Scott by about a month. Exhausted and suffering from frostbite, Scott died on the way home.

Picture Credit : Google

Life on Earth began about 3.5 billion years ago. The first life appeared in the sea. It was born into a world that looked very different from today. The atmosphere was filled with poisonous gases. The sky was pink, and the sea was rusty-red.

Is it true? Earth is the only planet with life on it.

Maybe. This is one of the greatest unsolved mysteries. Life probably does exist on other planets besides Earth, but nothing has been found so far. The search continues.

How did life begin?

It is thought that life began when lightning hit the sea. Lightning sent energy into the water. Chemicals in the sea were mixed together by energy. New substances, called amino acids, were made, from which life was able to grow.

Amazing! The first living things on Earth were so small you could fit thousands of them on the head of a pin.

What were the first living things?

The first living things were bacteria. They lived in the sea. Some bacteria changed into algae, which were simple plants. Algae lived in the sea in masses, like huge blankets. They made oxygen, which helped to turn the sky and sea blue.

Picture Credit : Google

About 440 million years ago, the first life appeared on land. It was simple plant life, similar to today’s mosses. Then, about 400 million years ago, the first land animals -worms, spiders, scorpions and insects - evolved as they moved on to the land.

Is it true? There are no amphibians alive today.

No. There are many different amphibians in the world today. Frogs, toads and salamanders are all amphibians.

Why did some fish grow legs?

Some fish began to live in shallow water. It was difficult to swim in the shallows. To help these fish move around they grew short legs. Some of them also grew lungs, which meant they could breathe air. These animals could live in water and on land.

Amazing! The lungfish is one of today’s fish that can live out of water. It can breathe air.

Which animal lives in water and on land?

An animal that can live in water and on land is called an amphibian. It means ‘double life’. The first amphibians appeared by 350 million years ago. Gradually, they spent more and more time on land.

Picture Credit : Google

Earth is millions and millions of years old. In fact, our planet is four-thousand-six-hundred-million years old. When the Earth’s age (4.6 billion years) is written as a number, it looks like this: 4,600,000,000. It’s hard for us to imagine anything so old.

Has there always been life on the Earth?

Nothing at all lived on the Earth for the first billion (1,000 million) years of the planet’s existence. The conditions were not right for life. There were no plants or animals of any kind. Earth was a dangerous place where life could not survive.

Amazing! Some of Earth’s oldest known rocks are found in Scotland. They are about 3.5 billion years old.

Has the Earth always looked the same?

These maps show how Earth’s land and sea looked in the past. To fit everything on them, Earth has been drawn as an oval. For a long time, all land was joined together in one giant mass. Over millions of years it broke up into smaller pieces. They turned into today’s continents.

Is it true? The continents are still moving.

Yes. The continents move about 4 centimetres each year - the length of your little finger. Millions of years in the future, Earth will look very different from today.