An introduction to global warming

by sarib khan
(bhopal,madhya pradesh,India)

What is global warming?

Global warming is when the earth warms up (the temperature increases). It happens when green house gases (such as carbon dioxide, nitrous oxide, water vapor, and methane) trap heat and light from our sun in the planet's atmosphere, and the temperature rises. This may hurt people, animals, and plants. Many can't take the change, so they die.

What is the greenhouse effect?

The greenhouse effect is when the temperature goes up because the sun's heat and light is trapped in our atmosphere. This is like when heat is trapped inside car. On a good hot day, the car becomes hotter when it is out in the parking lot, in the sunlight. This happens because the light and heat energy from the sun can get in the car, by entering through the windows, but it cannot get out again. This is what the greenhouse effect does to the atmospheric temperature. The energy can get through the atmosphere, but not back out again. As a result, net average temperatures rise.

The squiggle lines coming shown in the figure above from the sun are incoming light and the lines and arrows inside the car represent infrared electromagnetic radiation.

Heat from the sun can get into the car through the windows but then it is trapped. This makes that specific location, a car, a greenhouse, a building, or the atmosphere, warmer. The diagram shows the heat approaching the car in the form of visible light and infrared light (which transfers heat). Once the light energy makes it inside the car, it stays there and the heat builds up, just like it does in our air.

Sometimes the temperature changes in a way that benefits us. The greenhouse effect makes it possible for people to live on earth. And without it, the earth would be freezing in the dark, and burning hot in the light. Just like the surface of the moon. During daylight it would be burning because the sun would shine and no atmosphere redistributes the incoming energy, so people, animals and plants would be exposed to too much light and heat.

Although the greenhouse effect allows us to survive on earth, if there is be too high of a concentration of heat-trapping gases, the earth can get too warm, and life as we know it would cease. It would perish because there would be less food for instance. Why. Because the plants that provide food would not be able to take all the heat. We would then have less food to eat, and so would the animals. With a lack of food, like grass, animals that we need to survive (like cattle) would become more scarce and we would even have less food. Gradually, people, plants, and animals would starve.

What are greenhouse gasses?

Greenhouse gases are gasses are in the atmosphere that trap heat and light which arrive as sunlight. With too many green house gasses in the atmosphere, our natural blanket would trap too much heat and the planet would become too hot. Again, a mass global die-off could be expected.

What is global warming doing to the environment?

Global warming changes many parts of the world. It makes the sea level rise, and when that happens, water covers many low lands. Problem? The water covers plants and causes most of them to die. When they die off, the animals lose an important source of food, along with their place to live. Although animals may have a better capability to adapt to changes than plants do, they may also die. And when plants and animals die, people lose two key sources of food. We may also lose our homes. As a result, people would also need to leave the area or suffer. We then have a break in the food chain, a chain reaction, with one thing happening leading to another and so on.

The oceans are altered by global warming in other ways too. Many things that affect the ocean can be linked to global warming. One thing that is expected is warm water, resulting from global warming, enters the ecosystem and harms or kills algae in the ocean.

Why does that matter? Algae, that green stuff floating on the top of the water, makes food for animals through the process of photosynthesis, the same way all plants, like grass, do. Algae provides food to a variety of consumers (something that eats other living things) in the ocean. There are many consumers like fish, crabs, some varieties of whales, and other animals. Fewer algae presents a problem because animals have less food and so do we, eventually.

Global warming does many things to humankind as well as plants and animals. It kills algae and other species of plants, even huge forests. Pollution that causes global warming may also be linked to acid rain, which destroys most everything it touches. Global warming may also cause more fires which wipe out forests. This happens when global warming makes our earth too hot. In our forests, plants and tree-leaves can become so dry that they catch fire easily.

What causes global warming?

One thing is electrical pollution. Electricity results in pollution in a variety of ways. For instance, fossil fuels get burned to create electricity. These fuels are composed of dead plants and animals, carbon-based lifeforms. Some forms of fossil fuels include natural gas, oil and other petroleum products. Chemicals that pollute the water, air, and land enter the air when fossil fuels are combusted. Some of the chemicals released are called greenhouse gases.

We tend to use these sources of energy more than sources that pollute less. For instance, we rely too heavily on petroleum. It provides energy for transportation, producing electricity, and the manufacture of many other things. Although it results in polluting emissions, it gets used for 38% of the energy in the USA.

Barry's Response - Well, this all sounds familiar. Thanks for the input and the sketch, Sarib.