English: A graphical representation of data found in a table on World Population - Population Figures

It can clearly be seen that the total world population was steadily rising during the period 1000AD to around 1700AD, though with major disruption from outbreaks of plague (most notably the Black Death from 1350 AD - 1400 AD). Please see notes regarding the source data and method used for plotting the resulting population dips caused by both the Black Death and later plagues

Population grew at a faster rate from about 1700AD onwards, which coincided with the start of the Industrial Revolution There was then a sharp increase from the beginning of the 20th century followed by a very dramatic acceleration in population growth from the middle of the 20th century (around 1950) onwards.

At over 6.7 billion (see US Census data) the World Population is approximately 3 times higher in 2009 than it was at approximately 2.3 billion or less(historic census) in 1939, despite the appalling loss of life in World War II (an upper estimate of which is some 72 million).