Global Warming

Global warming (as well as global cooling) refers specifically to any change in the global average surface temperature.

It happens when greenhouse gases (carbon dioxide, water vapor, nitrous oxide, and methane) trap heat and light from the sun in the earth’s atmosphere, which increases the temperature.  This hurts many people, animals, and plants.  Many cannot take the change, so they die.

What is the greenhouse effect?

The greenhouse effect is when the temperature rises because the sun’s heat and light is trapped in the earth’s atmosphere.  This is like when heat is trapped in a car. On a very hot day, the car gets hotter when it is out in the parking lot.  This is because the heat and light from the sun can get into the car, by going through the windows, but it can’t get back out.  This is what the greenhouse effect does to the earth.  The heat and light can get through the atmosphere, but it can’t get out.  As a result, the temperature rises.

Sometimes the temperature can change in a way that helps us.  The greenhouse effect makes the earth appropriate for people to live on.  Without it, the earth would be freezing, or on the other hand it would be burning hot.  It would be freezing at night because the sun would be down.  We would not get the sun’s heat and light to make the night somewhat warm.  During the day, especially during the summer, it would be burning because the sun would be up with no atmosphere to filter it, so people, plants, and animals would be exposed to all the light and heat.

Although the greenhouse effect makes the earth able to have people living on it, if there gets to be too many gases, the earth can get unusually warmer, and many plants, animals, and people will die.  They would die because there would be less food (plants like corn, wheat, and other vegetables and fruits).  This would happen because the plants would not be able to take the heat.  This would cause us to have less food to eat, but it would also limit the food that animals have.  With less food, like grass, for the animals that we need to survive (like cows) we would even have less food.  Gradually, people, plants, and animals would all die of hunger. 

What are greenhouse gasses?

Greenhouse gasses are gasses are in the earth’s atmosphere that collect heat and light from the sun.  With too many greenhouse gasses in the air, the earth’s atmosphere will trap too much heat and the earth will get too hot.  As a result people, animals, and plants would die because the heat would be too strong.

What causes global warming? 

Many things cause global warming.  One thing that causes global warming is electrical pollution.  Electricity causes pollution in many ways, some worse than others.  In most cases, fossil fuels are burned to create electricity.  Fossil fuels are made of dead plants and animals.  Some examples of fossil fuels are oil and petroleum.  Many pollutants (chemicals that pollute the air, water, and land) are sent into the air when fossil fuels are burned.  Some of these chemicals are called greenhouse gasses.

We use these sources of energy much more than the sources that give off less pollution.  Petroleum, one of the sources of energy, is used a lot.  It is used for transportation, making electricity, and making many other things.  Although this source of energy gives off a lot of pollution, it is used for 38% of the United States’ energy.

Some other examples of using energy and polluting the air are:

•          Turning on a light
•          Watching T.V.
•          Playing a video game
•          Washing or drying clothes
•          Heating a meal in the microwave
•          Using an air conditioner
•          Using a hair dryer

When you do these things, you are causing more greenhouse gasses to be sent into the air.  Greenhouse gasses are sent into the air because creating the electricity you use to do these things causes pollution.  If you think of how many times a day you do these things, it’s a lot.  You even have to add in how many other people do these things!  That turns out to be a lot of pollutants going into the air a day because of people like us using electricity. The least amount of electricity you use, the better.

When we throw our garbage away, the garbage goes to landfills.  Landfills are those big hills that you go by on an expressway that stink.  They are full of garbage.  The garbage is then sometimes burned.  This sends an enormous amount of greenhouse gasses into the air and makes global warming worse.

Another thing that makes global warming worse is when people cut down trees.  Trees and other plants collect carbon dioxide (CO2), which is a greenhouse gas.

Carbon dioxide is the air that our body lets out when we breathe. With fewer trees, it is harder for people to breathe because there is more CO2 in the air, and we don’t breathe CO2, we breathe oxygen.  Plants collect the CO2 that we breathe out, and they give back oxygen that we breathe in.  With less trees and other plants, such as algae, there is less air for us, and more greenhouse gases are sent into the air. This means that it is very important to protect our trees to stop the greenhouse effect, and also so we can breathe and live.

With more heat trapped on Earth, the planet will become warmer, which means the weather all over Earth will change.  For example, summers will get hotter, and winters too.  This may seem a good idea, but the conditions we are living in are perfect for life, and a large rise in temperature could be terrible for us and for any other living thing on Earth.

At the moment, it is difficult for scientists to say how big the changes will be and where the worse effects will occur.

The Weather

In Britain, winter and summer temperatures will increase and the weather will be warmer.  In winter, it may also rain more but in summer it may become drier.

In other parts of the world, the effects will be different, some places will become drier and others will be wetter.  Although most areas will be warmer, some areas will become cooler.  There may be many storms, floods and drought, but we do not know which areas of the world will be affected.

Sea Levels

Higher temperatures will make the water of the seas and oceans expand.  Ice melting in the Antarctic and Greenland will flow into the sea.

All over the world, sea levels may rise, perhaps by as much as 20 to 40 cm, by the beginning of next century.

Higher sea levels will threaten the low-lying coastal areas of the world, such as the Netherlands and Bangladesh.  Throughout the world, millions of people and areas of land will be at danger from flooding.  Many people will have to leave their homes and large areas of farmland will be ruined because of floods.

Farming

The changes in the weather will affect the types of crops grown in different parts of the world.  Some crops, such as wheat and rice grow better in higher temperatures, but plants, such as maize and sugarcane do not.  Changes in the amount of rainfall will also affect how many plants grow.

The effect of a change in the weather on plant growth may lead to some countries not having enough food.  Brazil, parts of Africa, south-east Asia and China will be affected most and many people could suffer from hunger.

Water

Everywhere in the world, there is a big demand for water and in many regions, such as the Sahara in Africa, there is not enough water for the people.

Changes in the weather will bring more rain in some countries, but others will have less rain.

Plants & Animals

It has taken million of years for life to become used to the conditions on Earth.  As weather and temperature changes, the homes of plants and animals will be affected all over the world.

For example, polar bears and seals will have to find new land for hunting and living if the ice in the Arctic melts.

Many animals and plants may not be not be able to cope with these changes and could die.  This could cause the loss of some animal and plant species in certain areas of the world or everywhere on Earth.

People

The changes in climate will affect everyone, but some populations will be at greater risk.  For example, countries whose coastal regions have a large population, such as Egypt and China, may see whole populations move inland to avoid flood risk areas.

The effect on people will depend on how well we can adapt to changes and how much we can do to reduce climate change in the world.