The number of people alive now is at a record level and is increasing. In 2012, the human population exceeded seven billion for the first time. Each year about 75 million more people are born than die. This is known as the net increase.
This increase can be clearly seen in a graph of human population.
Graphs of this shape are called exponential. Interestingly, we see the same pattern of growth in many populations of living organisms with sufficient resources. There are many reasons why our population increases:
Scientists are unsure whether this population increase will continue for ever. Some think that the human population will continue to increase and humans will be able to solve any problems that come their way.
Others think that humans will run out of food, fresh water or other resources and the earth's population will stop increasing, but remain high. Whereas, other scientists think that the population will reduce significantly, this is called a crash. In the past, plagues have caused a rapid decline in the population (note the dips in the graph at 600 CE and 1200 CE), and this could be a possible explanation for a rapid decline in the population in the future.
As the population grows, the pollution we produce also increases, which may cause significant issues.