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Youth Group
What is Global warming?
We know, the Earth warms by solar radiation naturally but when we talk about global warming, we mean the changes in Earth temperature by human activities.
During the last century, the Earth has become 0.5ºC warmer for which scientists are concerned about. They believe that human activities and industrialization affect global warming.
Climate Change is a consequence of global warming, which causes changes in precipitation pattern, sea levels rise, and water resources and has a wide impact on vegetation, wildlife and the human health.
What are greenhouse gases and greenhouse effect?
Greenhouse effect is the rise of the Earth's temperature caused by increasing the level of greenhouse gases in the Earth's atmosphere.
Water vapor, carbon dioxide, nitrous oxide and methane are the major greenhouse gases, which absorb portion of the solar energy in the atmosphere. If these gases were not in the atmosphere, solar thermal energy would reflect to space and the Earth's average temperature would get 33ºc cooler than now.
Have you ever seen a greenhouse?
Greenhouse is a room made of glass that the sunlight goes through and warms the greenhouse.
Atmosphere around us is like greenhouse and greenhouse gases act like glasses in the greenhouse. Sunlight enters the atmosphere and passes through greenhouse gas layer. When the sunlight reaches to the earth surface, soil, water and other creatures absorb heat from it.
The glasses in greenhouse trap the warm air in the greenhouse, so that greenhouse becomes warmer than outside. That is why the greenhouse is a suitable place for growing plants in the winter.
Part of sunlight traps in the Earth atmosphere and the remaining part returns to the space.
If the amount of greenhouse gases exceeds the normal level in the atmosphere, less energy returns to space, and temperature of the atmosphere increases, which causes the earth to become warmer.
Natural greenhouse effect makes the Earth's temperature suitable for us; without this effect, nobody could live on the earth.
What is Climate Change and what are its impacts?
What is the difference between weather and climate?
It is a good weather when the sky is clear, it is warm and the wind is breezing.
Some parts of the Earth get enough rain and the weather is good seasonally. In some other parts the weather is cold with a lot of snow. You can also find deserts with hot and dry weather. So the climate of different places is different. You can understand the local climate by measuring temperature changes and precipitations but you have to measure them for several years.
It is a bad weather when the sky is cloudy, it is stormy, and it is snowing or raining.
The weather forecast tells us how the weather would be.
Find Babolsar, Shar-e-Kord, Bandar Abbas and Tabas in Iran’s map. The climate of these cities shows you the different climate of our country. Babolsar is known as having a rainy climate, Shahr_e_Kord has a snowy climate and Bandar Abbas has a hot and humid climate.
But the climate is changing. For example; Tehran is on Alborz mountains domain and used to have a snowy climate during winter, but because of climate change it does not have that much snow anymore.
Can we change the climate?
It is difficult to believe that human can change the climate. But scientists are sure that people send greenhouse gases to the air. After Industrial Revolution people changed the environment and climate through industrial activities.
We need energy for our daily activities. We get this energy from foodstuff. We use electricity for lighting and electric machines. We use fossil fuels for heating and running our cars. All of these activities need energy.
Before Industrial Revolution the amount of greenhouse gases released by people was not a lot. But these gases increased rapidly because of population growth and high consumption of oil, gas and coal, so that the concentration of greenhouse gases increased from 270 units before industrialization to 367 units at present time.
But when do you exactly release the greenhouse gases to the air?
Every time you are …
you are sending greenhouse gases to the air.
But why?
Because you use electricity and fossil fuels to do these activities. Where do the electricity and fuels come from?
Well, power plants burn fossil fuels to produce electricity. Refineries convert crude oil to gas, gasoline and other fuels. Natural gas is also a major fossil fuel. Burning fossil fuels produce greenhouse gases.
Therefore, if you consume more electricity, the power plants will use more fuel and thus more greenhouse gases will be produced.
Methane is also one of the greenhouse gases and when you are…
you send methane to the air.
Motor vehicles and factories produce large amount of greenhouse gases too.
What is the problem?
Why do not we want the earth get warmer?
Sometimes small problems can become big problems. For example, think about brushing your teeth; if you do not brush your teeth for one day, nothing will happen. But do you know what will happen if you do not brush your teeth for a month.
It’s the same with global temperature. If the temperature rises above the normal for a couple of days, it is O.K. The global temperature is almost constant. But if the temperature continues to rise for a long time the globe will have lots of problems.
The average global temperature increased about 0.5ºC during the last century. Scientists predict that in the next 100 years, the average earth temperature will increase by about 1.5 to 3.5ºC.
You may think, “It’s no big deal”. But it can change the climate unexpectedly. Even a small increase in the Earth temperature can change the climate in a long period of time.
Climate change can cause huge changes in oceans water level, agricultural fields, the air that we breathe, and the water that we drink.
What will happen?
Sometimes the climate change will cause natural disasters like floods, droughts and storms.
Icebergs melt in warm climate, so the seawater level will increase. Water in oceans and seas will expand because of warmer temperature. Expanded water occupies more space and therefore the sea level will rise.
If the globe gets warmer, more days will be hot, and diseases that thrive in warmer climate such as Malaria will occur and heat stroke will increase.
Children and elderly people in the poor countries are likely to suffer disproportionately from this disease, because these countries don’t have enough money to fight diseases.
Climate change and impacts on agricultural field and outputs decrease humans’ food sources. If the weather gets warmer, water will be evaporated and the fresh water resources will decrease.
Climate Change also affects animals and vegetations. If these changes occur slowly, they can adapt themselves. But if these changes happen rapidly, the wildlife will be in danger. For example, birds and animals cannot find a suitable place to migrate.
Scientists estimate the sea level will rise from a few centimeters to 1 meter. If this happens, the people who live in low line coastal areas and islands will lose their homes.
What can we do?
Global warming is a very serious problem but we can control it by some easy activities and work.
You know global warming happens because of greenhouse gases produced by our daily activities. So we can minimize the amount of greenhouse gases. For example: we can carpool to go to work or to school. By doing so less gasoline is consumed and less greenhouse gas will be produced.
Here are some easy suggestions to reduce greenhouse gases production.
Study and research
Read about environment. Ask your teacher or school librarian to find interesting books about environment and climate change. Our links also can help you to learn more.
Turn off the light, TV, computer when you do not use them. Use bike, bus or walk
You can save energy and gas by using bike, bus or even walk instead of driving your car. Encourage others
Tell your friends and family what you know about global warming and warn them. Plant trees
Planting trees is fun and also helps reduction of greenhouse gases, because trees absorb carbon dioxide from atmosphere and produce oxygen.
RecycleSeparate empty cans, bottles, plastic bags, waste papers from other wastes. So you will send less garbage to landfill and it helps to save natural resources like trees, oil, metals (Al, Fe) etc. Buy high efficient appliances
Use appliances which consume less electricity to reduce greenhouse gas production. We can protect our environment by saving energy. There are some appliances like refrigerators, stoves etc., which consume less electricity.
Look for energy guide sticker Nowadays, most computers, TVs, stereos, VCRs etc. have energy guide sticker. These appliances consume less energy and protect the environment too. Buy recycled materials
You can protect environment by purchasing recyclable material instead of non-recyclable. Look for recycle sign on the things you buy. Recycle materials (egg box, plastic, containers, etc.) are usually made of recyclable material, and less energy has been consumed for their production. Use solar energy
Imagine that it’s a warm day in summer and you put an ice cream on the sidewalk in the street. What happens? Of course the ice cream melts, but why?The sun heat melts the ice cream. This heat is the solar energy. People can use solar energy for heating their houses, commercial buildings, water and even producing electricity. However, it is expensive, but it doesn’t need maintenance.
Now, the “Yazd Solar-Powered Electricity Generating Plant” produces electricity of solar energy in Iran. Less use of cars
Cars are one of the essential items for our life. Most of these cars make pollution and send large amount of greenhouse gases to the atmosphere. Some of the cars are environmental friendly. They can be driven more distance with less energy, also they make less pollution than others. Using energy efficient cars can help to reduce emission of greenhouse gases to the air.
2002, Iran's Climate Change Office, Tehran, Iran
Please send your comments to
info@climate-change.ir