The earth is considered as one of the most beautiful planets in the universe. It is the only planet in our galaxy that has enough water to support life. Unfortunately our planet is suffering due to many problems which should be solved before it is too late. The major problems that are facing our world today are population, pollution and animal extinction. One of the problems facing our world is population. It began about ten thousand years ago when the humans settled and began farming. The farming provides more food for the people thus making the population grow. Now we are about 6 billion in population and in a few years we will be around 10 to 11 billion. Therefore, our population will almost double in size. This means that we will need more food to support us. A study in 1986 by Peter Vitonesk, a Stanford biologist, showed that the humans are already consuming about 38.8 of what is possible for us to eat. Thus, if the population keeps increasing, the percentage will increase also, making us closer and closer to the biophysical limits. By studying the earth's capacity, Dr. Cornell, another biologist, believes that we are already crowded for this would. He believes that our world can only support two million people. Not only this, but population can cause complicated problems to the countries with very high population. These countries will need more schools to educate its people, they will need more hospitals and public health to take care of their people, and they will need more water and more soil for farming to feed all the people. In order to solve the population growth problem, the people should be educated. Once the people are educated they will be aware of the problems they cause when they have more than two children. Therefore the next generation should be educated and aware of what is going around them. Pollution is another major factor that is threatening our world today. One example of pollution is nitrogen.