What is global
warming?
Global warming is when the earth heats up (the temperature rises). 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.
The sun’s heat can get into the car through
the windows but is then trapped. This
makes what ever the place might be, a greenhouse, a car, a building, or the
earth’s atmosphere, hotter. This diagram
shows the heat coming into a car as visible light (light you can see) and
infrared light (heat). Once the light is inside the car, it is
trapped and the heat builds up, just like it does in the earth’s
atmosphere.
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 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:
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2013年1月1日星期二
Globle warming
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