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What is global warming?
Global warming is the term used to describe the rising of the average temperature on Earth. It has to do with the overall climate
of the Earth rather than the weather on any given day.
History of Global Temperatures
The Earth has gone through changes in temperature before. The Earth has even gone through several ice ages, when the temperature dropped significantly and a lot of the world was covered in ice glaciers. Each time the planet eventually warmed up and melted the ice.
Why is global warming important?
Even small variations of the planet's average temperature can have a large impact on the environment. For example, the ice ages that occurred generally involved a reduction in the global temperature of around 5°C.
Here are few of the things that scientists think may happen as the temperature rises. Some of them are already happening:
- Glaciers melting - Many glaciers are already melting and shrinking throughout the world. If the temperature increases they will continue to melt.
- Ocean levels will rise - As the glaciers melt, the ocean levels will rise. This could cause flooding in cities located near the coast.
- Migration of animals - Animals will migrate to cooler spots as their old habitats get too warm. This could upset the food chain and put some species in danger of extinction.
- Extreme weather - Some scientists think that warming will fuel more powerful hurricanes as well as more droughts and flooding in different areas of the world.
- Change in ecosystems - cold weather biomes such as the tundra will shrink, while desserts will continue to expand.
What causes global warming?
Greenhouse gases like CO2 heat the Earth
Global warming is a very complex subject. Some scientists disagree as to what caused the rise in temperatures that occurred during the end of the 20th century. Things that can have an impact on global warming include the natural temperature fluctuations of the planet, greenhouse gases such as carbon dioxide, volcanic eruptions
, and increased solar activity.
The average temperature of the Earth has changed throughout history. Some of this is due to natural changes in temperature that occur over time due to a large number of variables. Even slight changes in nutrient cycles such as the carbon cycle
, the oxygen cycle
, and the water cycle
likely have an impact on the climate over time.
Some scientists think that the current warming trend is just a part of the Earth's natural changes in temperature and it will eventually start to cool again.
The reason the Earth isn't a ball of frozen ice is because of greenhouse gases. Greenhouse gases act like insulation to keep the Earth warm. However, as more and more greenhouse gases get into the atmosphere, the Earth will start to grow warmer. The main greenhouse gases that keep the Earth warm are water vapor, carbon dioxide, and methane.
In the past 100 years humans have been the cause of a significant increase in greenhouse gases in the atmosphere, especially carbon dioxide. Every time we drive our cars or use electricity, more carbon dioxide is released into the air.
Since all the energy and heat on the Earth comes from the sun
, it follows that the sun's activity will have some effect on the temperature of the Earth. The activity of the sun is actually different over time, which can change how much energy actually hits the Earth.
When volcanoes erupt they can change the temperature of the entire Earth for a short period of time. This is because their eruptions send large amounts of ash and particles into the atmosphere. This blocks some of the sun's rays from hitting the Earth and can cause the Earth to cool. At the same time, volcanic eruptions emit large amounts of carbon dioxide into the atmosphere.
What can we do about it?
We can't do much about the Earth's natural fluctuations, volcanic eruptions, or the sun's activity, but we can impact the amount of greenhouse gases that are emitted into the air. Many of our everyday activities cause more carbon dioxide to be released into the atmosphere including driving cars and using electricity. You can help by trying to cut down on the amount of electricity you use as well as how much driving you (or your parents) do. Things like carpooling to events and planting trees can help.
One way to measure how much carbon dioxide you contribute to the atmosphere is by calculating your carbon footprint. There are a lot of variables to consider including the gas mileage of your family's car and how your local power plant generates its electricity.
A lot of the same activities that produce carbon dioxide also cause air pollution, so by lowering your carbon footprint you can help the environment in many ways.
Facts About Global Warming
- It takes lots of data and many years to determine how the average temperature of the Earth is changing. Even then, many scientists disagree on how to interpret the data.
- Since 1990, worldwide carbon dioxide emissions have risen by over 20 percent.
- The United Nations formed a group called the International Panel on Climate Change to investigate global warming.
- One way to reduce carbon dioxide is to use clean renewable energy sources such as solar energy and wind energy. These sources produce much less pollution as well.
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