Earth's surface temperatures are set to rise by 2.7°C by 2100 compared to the pre-industrial era. This is expected to affect more than two billion people — or 22 percent of the world's population by that time.
India, Nigeria and Indonesia have the largest number of people who could face deadly heat under this scenario, numbering 600 million, 300 million and 100 million, respectively. But by putting a limit on warming at 1.5°C, the most ambitious goal of the 2015 Paris Agreement, the number at risk is reduced to less than half a billion.