Climate Change (1-4) (1)

The Earth's climate

Today, the Earth's climate has a huge effect on the daily lives of all the people in the world. It has always had a big effect on life on Earth, and it had a big effect on how life started billions of years ago.

So, what is climate? Climate is the usual weather in a place over a long time - normally thirty years or more. Weather can change quickly, and a place can have very different weather from one day to the next. But climate is those weather patterns over a long time.

On Earth, lots of things have an effect on the climate - the atmosphere, the oceans, the land, ice, people, plants and animals, and the light and heat from the Sun.

The Earth's atmosphere is a thin layer of gases above the Earth.

The Earth's atmosphere

Most of the atmosphere is nitrogen (N2) and oxygen (O2), but there are other gases in the atmosphere, too.

Some of the gases in the atmosphere are called greenhouse gases because, like the glass in a greenhouse, they keep the Earth warm. They do this by stopping some of the Sun's heat from leaving the Earth. They are very important because they help to keep the Earth at the right temperature for life to grow - not too hot and not too cold. Carbon dioxide (CO2) is a very important greenhouse gas. Without the greenhouse gases, the Earth would be very, very cold.

Many scientists study the Earth's atmosphere. They do this from satellites and from the land, and their studies show that the amount of greenhouse gases in the atmosphere is growing. This is making the temperature on Earth get warmer, and this warming is having a big effect on the climate.

We are already seeing the effects of this all over the world. Weather patterns are changing; the water in the oceans is getting warner; snow and ice are melting in the Arctic and Antarctica; and sea levels are increasing.

These effects can cause many problems for the people on Earth, and for the beautiful plants and animals that live on Earth, too. They could mean there is not enough food and water for everyone; they could have a damaging effect on people's health; and they could make some people poorer. We need to act now to stop climate change and to make a better future for our world. If we do not act now, we will put the future of our world in danger.

CHAPTER TWO

A warmer world

Weather stations across the world give us information about the temperature on the Earth's surface. We also get information from ships and buoys in the oceans. All this information helps scientists to decide if the temperature on Earth is going up or going down.

Information from the last 150 years shows that the temperature on the Earth's surface has gone up. The temperature in some places has increased more than others, and the warming in the Arctic is greater than in all other places on Earth.

Some years have always been warmer or colder than others, and the Earth's climate has changed a number of times in the past. This is because natural things can cause the Earth's temperature to change from one year to the next, or to change over a longer time. These things include the amount of heat coming from the Sun, the effect of volcanoes and weather patterns like El Nino.

But, for many years, scientists have talked about climate change and the warming of the Earth. Each of the past four decades has been warmer than the one before.

The information we get from weather stations, ships and buoys shows that, since the year 2000, the Earth's temperature has been 0.75 degrees Celsius warmer than it was 150 years ago. But, in 2015, the temperature became 1 degree Celsius warmer than 150 years ago. This is a big increase, and scientists are worried about it.

Other studies also show that the Earth is getting warmer. For example, studies show that the temperature of the oceans is increasing - from the surface, right down to the bottom of each ocean. Other studies show that the amount of snow and ice on the Earth's surface is getting smaller.

Melting ice and increasing sea levels

The warming of the Earth is causing the Arctic sea ice to melt. In the 2010s, at the end of the summer, the Arctic sea ice was one third smaller than at the end of the 20th century. That's a change of the same size as the UK, Ireland, France, Spain, Germany and Italy put together. When the Arctic sea ice melts, it can change the weather patterns in Europe, Asia and North America. As the Earth gets warmer, the water in the oceans gets warmer, too. This makes the water expand get larger. This makes sea levels increase. Also, the land ice in Greenland and Antarctica is melting, and this, too, causes sea levels to increase. Studies show that sea levels across the world are increasing.

When sea levels increase, floods from storms can be more dangerous for people living near the sea. Many of the world's biggest cities, like Shanghai in China, Jakarta in Indonesia and Mumbai in India, are very close to the sea. Higher sea levels put these cities in danger of floods.

The floods in New York City in 2012 showed the damage that big storms can do. These floods caused huge problems for the people of New York City. They damaged homes and other buildings, and many people had no electricity in their homes. This meant no heat, no light and no way to cook food or heat water. The damage caused by big storms can have an effect for many years and can cost billions of pounds.

For now, the Thames Barrier on the River Thames in London protects the city from floods, but, if sea levels increase, the barrier might need to be bigger. And many other cities across the world do not have anything to protect them from higher sea levels and the floods they can cause. The warming of the Earth puts all of these cities in danger. In many places, building a barrier like the Thames Barrier is either not possible or too expensive.

CHAPTER THREE

The effects of a warmer world

Heatwaves, droughts, floods and storms

Heatwaves, droughts, floods and storms are all extreme weather. A heatwave is very hot weather for many days, and a drought is very little rain for a long time. Extreme weather can cause huge damage to buildings and roads, and to people and animals. The damage caused by extreme weather can cost billions of pounds, and many people can lose their lives.

In 2016, there was an extreme heatwave in India. The country had its highest-ever temperature at 51 degrees Celsius, and many people died. In Europe in 2003, there was a summer heatwave that killed tens of thousands of people. Most of these people were old, because very hot weather can cause more problems for older people.

In Australia, there have been many large fires over the last few years. In the Australian summer, the land, and the plants growing on the land, can get very dry. It is then easy for a fire to start and to become very large, very quickly. These fires badly damage people's homes and other buildings, and many people lose their lives in the fires.

Since the year 2000, parts of the UK have had floods again and again, and these floods have caused huge amounts of damage. In 2010, there were extreme floods in Pakistan. These floods had a terrible effect on 20 million people in the country. Many people lost their lives, and even more people lost their homes. It takes a huge amount of time and money to help people after damaging weather like this.

All over the world, we are seeing patterns of extreme weather. Many places are having their highest-ever temperatures, and other places are having more rain than ever before. The effects of this extreme weather are very dangerous for all the living things in our world. The number of heatwaves, droughts, floods and storms we are seeing is increasing in many places. Extreme weather is now becoming normal for many people. There has always been extreme weather, but studies show that climate change has increased the risk of extreme weather. A warmer world increases the risk of Europe having a big heatwave, for example.

Studies on the floods in the UK show that the risk of extremely heavy rain is greater because of climate change, and this has made the risk of floods in this part of the world higher. One reason for this is because a warmer atmosphere can hold more water, so the rain is heavier and the risk of floods is greater.

The effects on people and where they live

Climate change can also have an effect on our food and water, and on our health.

All over the world, we grow food on farms. Much of the food we buy at supermarkets starts its life in a field or on a farm. But the food we grow needs the weather to be just right - not too hot, not too cold, not too wet and not too dry. Droughts and floods have a very damaging effect on how much food we can grow. When fields become too wet or too dry, plants cannot grow. This can increase the price of food, and then poor people cannot buy it. These people then have to go hungry. Some plants may grow better in a different climate. But scientists think that the effects of climate change will make it much harder to grow enough food for everyone.

Climate change may also have an effect on the amount of water that we have, and many places may not have the water they need. Across South Asia and China, water for drinking and farming comes from large rivers. The water in these rivers comes from rain and snow, and from ice melting high up in the Himalayan mountains. Climate change can have an effect on all of these things. This means lower amounts of water in the rivers and lower amounts of water for people to drink and use.

Climate change and extreme weather can also have a damaging effect on our health. More people could catch some diseases in a warmer world. Dirtier air can also damage the health of all living things.

The many effects of climate change can make people feel worried about their lives and their families. When people do not have the food and water they need, it can cause problems between groups of people and communities. Sometimes people move from their homes to try to find a better place to live or to find enough food and water.

The effects on animals

Climate change is causing problems for many of the animals that live on the Earth. Changes in temperature, the seasons (spring, summer, autumn and winter) and the amount of food and water animals can find all make life much more difficult for animals in different parts of the world.

When changes to the climate are slow, animals can find ways to live with the changes. But when changes to the climate happen very quickly, it is much more difficult for animals to do this. The climate change we are seeing right now is happening very quickly, and it is damaging for many of the living things on Earth. At the same time, animals are losing their habitats - the places they live. People cut down trees to build towns and cities and to grow food in fields. All of these things take habitats away from animals.

Together, climate change and losing habitats make life very difficult for the animals of this world. We may see some animals become extinct in the future because of climate change. Many animals already have problems, and there are very low numbers of some animals in today's world. More climate change may mean that these animals become extinct, and we never see them again.