By Sarah Parsons and Liz Saccoccia
Temperatures in Karachi, Pakistan’s most populated city, have soared above 113 degrees F in May 2018. Sixty-five people have already died due to heat-related illnesses, and NASA data shows it’s just a taste of what’s to come if emissions continue unabated.
The map above shows projected change in extreme heat days in 2051-2080 compared to 1971-2000, under a high emissions scenario. Karachi experienced an average of five extreme heat days per year in 1971-2000; that number is projected to increase to 79 by 2051-2080.
Why Is Karachi So Vulnerable to Heat?
This is just the latest heat wave to hit Karachi. Part of the reason the city is so vulnerable to extreme heat is because of urban heat island effect, a phenomenon where cities are significantly warmer than the rural areas surrounding them. Experts blame trapped heat from dense populations and industrial processes, as well as the lack of green spaces and trees to cool temperatures.
Data from Columbia University’s Center for International Earth Science Information Network shows that the urban heat island effect is particularly extreme in Karachi. The average difference in summer daytime temperature between the city and surrounding areas is 2.9 degrees C (5.22 degrees F). The global average difference is only 0.73 degrees C (1.3 degrees F).
LEARN MORE: Find out how urban heat island effect and extreme heat days affect your city.