There are many theories that deal with this question. The UN report “World Population Prospects: The 2012 Revision” currently provides the most reliable figures. According to its estimates, there will be 8.1 billion people on Earth by 2025, and 9.6 billion by 2050. Some African countries, the Philippines, Indonesia, India, Pakistan and also the USA will see particularly strong population growth. However, the rate at which the global population is increasing has already begun to slow down. So when will the population growth level off, or even start to decline? This kind of prediction cannot be made on a global scale. However, it is possible to make predictions for individual continents and countries. The population of European countries is already increasing at a slower rate and, largely due to consistently low birth rates in many countries and insufficient immigration, will decline in the long-term – by about 14% between 2013 and 2100. China’s population will presumably begin to decline in 2030. The population of India is expected to decrease after reaching a peak of 1.6 billion around the middle of the century. On the other hand, the population of Nigeria could exceed that of the USA by 2050. In fact, by the end of the century Nigeria could be competing with China as the world’s most populous nation. The population of Africa could double from 1.1 billion to 2.4 billion by 2050, and could potentially reach 4.2 billion by 2100. The global population will therefore not cease to grow in the foreseeable future.
Dr Susann Beetz of the Ideas 2020 team answered this question with the support of Dr Andreas Edel of Population Europe / Max Planck Institute for Demographic Research.