Among the problems we face, I think poverty is the biggest problem. My reasons are as follows.

To begin with, there are still many people dying of starvation in many poor countries. They don’t have enough food, for they have no money. It’s no doubt that eating unhealthily will result in illness. What’s more, people in these undeveloped areas usually lack of proper health care. Thus, infectious diseases like AIDS spreads fast. That is terrible.

In addition, their clothes are too worn to be called “clothes”, and thus many of them are frozen to death. The little match girl in Andersen's fairy tale is just a case in point. Such a problem is mostly caused by lack of money, in other word, poverty.

From over above we can safely draw a conclusion that poverty is the biggest problem in Earth.