The first reason is that the Earth does not have enough resources for everyone; therefore, people will lack food and water. The space for farmland and living in each country is limited. For instance, in Hong Kong, there are more than 7 million people living an area of nearly 1,100 square kilometers. In addition, it is very difficult to share food and water for all people. For example, the poverty in Africa is because they lack of water. There are nearly 1 billion people in this country do not have clean water. Also, because the weather is hot and dry, not enough rain, so they cannot grow crops and thus, the food is not enough. According to an investigation, around 40,000 children die because of hunger and diseases cause by lack of food.
The second reason to support this point is that overpopulation causes pollution for the environment. If more people are born, we need more space to build houses to live; so more trees are cut down. As a result, the amount of rubbish and exhausted fumes is higher. It makes the environment polluted. The situation is more serious in developing countries as these nations use the bad technology to build houses and develop their economy. To compete with developed countries, they use cheap technology. They can produce goods quicker, at a lower price, but it is not good for the environment