A study published in the Proceedings of the National Academy of Sciences journal found that exposure to dangerously high temperatures in cities tripled between 1983 and 2016. This product of climate change poses a serious public health risk to urban dwellers. In 2003, 70,000 people died from an extreme heat wave in Europe. Fifteen thousand died in France alone; Paris tallied the most excess deaths.
The Earth is nearing the safe limits of climate change say many climatologists. Urgent action is needed now to avoid even worse consequences of anthropomorphic heating. This chart shows the alarming increase in person-days of extreme heat at the city level:
The decade beginning in 2011 is the hottest on record. Average global temperatures peaked in 2016, 2019, and 2020. The planet has already experience a 1.8°F increase in average global temperature since the 1950s. According to researchers, the number of people exposed to extreme heat could swell ten fold in the next decade driven by increased urbanization in developing regions and an increase in global temperatures. Note the red areas concentrated in India and west Africa in the chart above. More than half the world's 7.7 billion population is packed into cities that figure is expected to increase to 68% by 2050. The most significant gains are expected in China, India and Nigeria, Africa's most populated country. Dense urban metropolises, bereft of cooling vegetation and immersed in heat emitting vehicles, concrete buildings and pavements are heat sinks that further elevate ambient air temperatures. Most at risk of death from heat exposure are the poor and elderly who are unable to escape the heat.