In the 1990s, the global population reached a significant milestone, surpassing six billion people. This figure marked a remarkable increase, more than tripling the population size at the onset of the First World War. The rapid growth of the world’s population during this century has had profound implications for society, economics, and the environment.

Niall Ferguson, in his book "The War of the World," highlights this demographic shift, emphasizing how historical events and conflicts have been intertwined with population changes. The exponential growth signifies not only advancements in health and technology but also presents challenges that need to be addressed to ensure sustainable development.