Global Warming

Many scientists believe that deforestation is causing the earth to become warmer. This is because of what is called the greenhouse effect. The greenhouse effect works like this: The sun's rays pass down through the atmosphere and warm the surface of the earth. The surface throws some of the heat back toward space. However, much of that heat does not escape into space. Gases in the atmosphere called greenhouse gases trap it. This happens the same way a glass garden greenhouse traps heat to grow plants in the winter. The main greenhouse gases are carbon dioxide, methane, nitrous oxide and chlorofluorocarbons (CFCs).

People have been putting more and more greenhouse gases into the atmosphere, especially in the past hundred years. Many scientists believe this increase in greenhouse gases will slowly cause the earth to become warmer. This is called global warming. Many scientists also believe that global warming could cause the polar ice caps to melt. This may cause flooding of low-lying coastal lands. A rise in temperature could be enough to endanger the crops we need for food. It could also dry up the lakes and rivers in some areas that provide water to crops, towns and cities.

Deforestation is a major cause of carbon dioxide being released into the atmosphere. Trees and other plants in the forests absorb carbon dioxide to make food. As forests are destroyed, fewer trees are available to absorb carbon dioxide. Also, people often burn the trees when clearing land. This burning releases large quantities of carbon dioxide into the atmosphere. For the same reasons, the cutting and burning of wood for curing tobacco adds to the greenhouse effect.

The smoke from cigarettes also contains greenhouse gases. Cigarette smoke contains carbon dioxide and methane. Smoking worldwide releases about 2.6 billion kilograms of carbon dioxide in the air every year. It also releases about 5.2 billion kilograms of methane every year. Tobacco growing, curing, and smoking all add to the greenhouse effect and global warming.