HUMANITY is at threat from these five major problems, including artificial intelligence (AI), bioengineered diseases and the death of the Sun. Could these threats spell the end of the world? Below replacement fertility levels While underdeveloped countries in Africa face the threat of unsustainable population growth and limited resources, many wealthy nations have the opposite problem – a declining population that could pose a threat to the future of humanity. In 2016 there were 106 nations – just over half listed by the CIA World Factbook – that were below replacement level fertility, meaning that they are not producing enough newborns to replace the previous generation. In developed countries, an average fertility rate of at least 2.1 births per women is needed to keep population numbers stable. But in countries such as Germany, Japan and South Korea, the average birth rate is just 1.4 children per woman. In the UK that number grows slightly to 1.89 – still well below the amount