Introduction

In this section, we'll see how the greenhouse effect can cause global warming.

Greenhouse Effect

A simple model of Earth's temperature-control system:

The sun supplies Earth with the heat it needs to support life.

A layer of ozone far above Earth blocks out some dangerous ultraviolet radiation, while allowing other solar radiation to pass through.

Much of the remaining radiation enters the atmosphere, is absorbed by the ground, and is reradiated from the ground to the atmosphere.

Greenhouse gases like carbon dioxide (CO2), methane (CH4), water vapor (H2O), ozone (O3), dinitrogen oxide (N2O), and chlorofluorocarbons (CFCs) keep Earth warm enough for life by holding heat radiation in the atmosphere. Carbon dioxide is the most important of these greenhouse gas. The system of greenhouse gases forcing heat in to keep Earth warm is called the greenhouse effect. This effect keeps Earth near a natural temperature.

Global Warming

Since the 1850s, as consumerism has taken off, manufacturing and transportation industries have burned millions of pounds (or kilograms) of coal and millions of gallons (or liters) of gasoline. Burning of coal, gasoline, and most other fuels produces exhaust which contains greenhouse gas.

The exhaust, especially the greenhouse gas, emitted by these industries has built up in the atmosphere. The greenhouse gas buildup has added to the natural greenhouse effect and has caused an unnatural global warming. This is what is usually referred to as global warming.

As you can see, several of the greenhouse gases emitted by industries have added to the greenhouse effect. Of all of them, carbon dioxide (CO2) has been most responsible for global warming.

Conclusion

Take the Causes Quiz to test your understanding of how the greenhouse effect causes global warming. Then proceed to the Dangers section and discover some of the dangerous consequences of global warming.