This link says it all about our overly crowded and overly populated world: http://www.worldometers.info/world-popul...
Overpopulation can have a number of effects, most of which are negative as examined below.
Lack of Water
Overpopulation creates greater demand on the world’s freshwater supplies. As only roughly 1 percent of the world’s water is fresh and accessible, this creates a major issue.
Some estimates state that human demand for fresh water will stand at approximately 70 percent of what is available on the planet by 2025. This will place those living in impoverished areas that already have limited access to such water at great risk.
Lower Life Expectancy
While higher life expectancy is leading to increases in population in developed countries, lower life expectancy may be caused by the booms in population that less developed nations are experiencing.
A large proportion of the world’s population growth occurs in less developed countries. This stretches the resources these countries have thinner resulting in less access to medical care, fresh water, food and jobs, all resulting in a fall in life expectancy.
As the population grows, so too does the amount of resources needed to keep so many people alive. Food, water and fossil fuels are all being consumed at record rates, placing greater demands on producers and the planet itself.