Populations go down for a variety of reasons, broadly classifiable as increasing death rates (war, disease, famine, natural disaster such as earthquake or tsunami) or decreasing birth rates (which happens generally as a result of higher standards of living - wealthier people want fewer children).
Second opinion, government could but they won't and common sense if they don't Mother Nature will take care of it at some point. Only problem is she may do too good of a job. We had our chance and blew it. 7 billion now, 9 billion by 2040 which means 12 billion by 2100. The planet cannot support that many and will take care of the problem. No one in power wants to admit to the facts and make the hard choices now that could maybe give us a chance. People just keep breeding like rats and we will all pay the price.
The causes of human population to decrease are as folllows:
Populations grow as long as there is sufficient:
They also are controlled by:
Some facors that would cause population to decrease is shortage of food, low Birth Rate, diseases, emigration, and lack of money or jobs.
If a population decreases it could be because of a disease epidemic, shortage of food, or a decrease in reproduction for example in china they have the one child policy.
you can have a lack of food, urban space, fresh water sources, high taxes, too few hospitals, lack of police, a slack in the law, bad weather, poor entertainment sites, and so much more.
decrease in birth rate can lead to the population decreasing
it is an environmental factor that causes a population to decrease.
It is called a limiting factor.
More predators so the population would decrease :(
The general term for an environmental factor that causes a population to decrease is a limiting factor. Some examples are emigration and mortality, a lack of resources, natural disasters happen which makes people scared to to live there so the people flee, and habitat loss.
limiting factor
Factors that decrease population growth can be defined as environmental stress including limitations in food, predation, and other density-dependant factors
The environmental factor is excessive sun exposure.
Decrease
its considered a limiting factor because it might have the power to decrease the numbers of the population, if one were to become infected.
The general term for an environmental factor that causes a population to decrease is a limiting factor. Some examples are emigration and mortality, a lack of resources, natural disasters happen which makes people scared to to live there so the people flee, and habitat loss.
Pollution was a small factor but the largest factor is the spread of the Asian Carp which feed on algae and surface insects. This causes a disruption in the entire river ecosystem all the way to the largemouth bass causing a decrease in available food and therefore a decrease in population.
It increases the odds of mutation.