Half of the world's population will live in extreme heat by 2050. Some 3.8 billion people will experience extreme heat if the world reaches 2°C of global warming, a scenario that scientists see as increasingly likely. In 2010, only 23% of the world's population lived in extreme heat. According to research published in the British journal Nature Sustainability, this percentage will rise to 41% in the coming decades. The study highlights that the 20 countries with the most significant changes in cooling degree days (CDD) are all developing nations, mainly from Africa, Central America, South America, and Southeast Asia, as they are located near the equator and in subtropical latitudes. In the case of South America, the countries most affected by extreme heat in 2050 will be Brazil, Venezuela, and Paraguay. While in Central America, the study cites Honduras, Guatemala, and Nicaragua as the nations that will experience the greatest variations in CDD.
