Sooner or later we won’t have enough food and shelter for people because the population  is growing so fast. We either need to find a way to keep them or try to limit their population.

Between 1960 and 1999, Earth’s population doubled from three billion to six billion people. In many ways, this reflected good news for humanity: child mortality rates plummeted, life expectancy increased, and people were on average healthier and better nourished than at any time in history. However, during the same period, changes in the global environment began to accelerate: pollution heightened, resource depletion continued, and the threat of rising sea levels increased. Does the simultaneous occurrence of population growth and environmental decline over the past century indicate that more people translate into greater environmental degradation?

The ways in which populations are distributed across the globe also affect the environment. Continued high fertility in many developing regions, coupled with low fertility in more-developed regions, means that 80 percent of the global population now lives in less-developed nations. Furthermore, human migration is at an all-time high: the net flow of international migrants is approximately 2 million to 4 million per year and, in 1996, 125 million people lived outside their country of birth.

Much of this migration follows a rural-to-urban pattern, and, as a result, the Earth’s population is also increasingly urbanized. As recently as 1960, only one-third of the world’s population lived in cities. By 1999, the percentage had increased to nearly half 47 percent. This trend is expected to continue well into the twenty-first century. Over the years the population has tripled and they keep rising which is not good. We need to find a way out quickly for environmental safety.