‘From 55,000 to 7 billion’ describes how global population has evolved over time and space, experiencing a small increase for thousands of years, until around 200 years ago when global population grew dramatically. 1.2 million years ago there were around 55,000 humans, then by the end of the last ice age 20,000 years ago there were around 1 million Homo sapiens. The next 15,000 years saw a dramatic evolution in human economy and society and by 5000 bc the world population reached around 5 million. It took a further 7,000 years for population to reach one billion by ad 1800. Population now stands at some 7 billion and is projected to reach around 10 billion during this century.