March, April, and May 2024 set new records for monthly global temperatures. The effects of climate change caused by the burning of fossil fuels are evident, especially in the form of extreme heat. Using the Climate Shift Index (CSI), the Climate Central report found that every day from March 1 to May 31, 2024, one in four people worldwide experienced temperatures at least three times higher than normal due to climate change.
On April 6, 2024, one in three people worldwide experienced extreme heat with a CSI of 3 or higher. In 58 countries, including Southeast Asia, the average population felt the strong impact of climate change on at least two out of every three days over the past three months.
The report also found that Brunei was the most vulnerable country in Asia to climate change, with its population experiencing very high impacts (CSI 3 or higher) for an average of 90 days per year. On the other hand, Indonesia had the highest number of people exposed to CSI 5 for more than 60 days, with a total of 2.2 million people.
Overall, 71% or 3.3 billion people in Asia experienced at least one day of very high exposure to climate change (CSI 3 or higher). About 9% of Asia's population, particularly in Southeast Asia, experienced extreme heat (CSI 5) for at least 60 days in the past 3 months.
In 9 Southeast Asian countries, the average population experienced this impact on at least two out of every three days in a season. In these countries, including Brunei, Malaysia, East Timor, Singapore, and Indonesia, the impact of climate change was very high on 88% of the days in a season.
The effects of the heat wave were also felt in several countries. In the Philippines, schools were forced to close. In Thailand, parents were advised not to let their children play outdoors. Myanmar even recorded its all-time high temperature for April at 48.2°C, and Laos broke its national record at 43.6°C.
Extreme heat in major cities around the world has been increasing rapidly due to climate change. Here are some Southeast Asian cities with the most days of extreme heat (CSI 3 or higher) in the last 3 months:
- Makassar, Indonesia: 92 days, temperature anomaly 1.2°C
- Davao, Philippines: 88 days, temperature anomaly 0.9°C
- Semarang, Indonesia: 88 days, temperature anomaly 0.9°C
This condition is exacerbated by population density and land development patterns in cities, creating the urban heat island effect. Of 48 major cities worldwide, 40 experienced at least one day with climate change-influenced temperatures (CSI 3 or higher).
Some of the major cities in Southeast Asia experiencing extreme heat include
- Jakarta, Indonesia: 77 days with temperature CSI 3 or higher, 69 days with temperature CSI 5 or higher, temperature anomaly 0.9°C.
- Ho Chi Minh City, Vietnam: 76 days with temperature CSI 3 or higher, 62 days with temperature CSI 5 or higher, temperature anomaly 1.2°C.
- Manila, Philippines: 75 days with temperature CSI 3 or higher, 67 days with temperature CSI 5 or higher, temperature anomaly 1.2°C.
- Bangkok, Thailand: 69 days with temperature CSI 3 or higher, 58 days with temperature CSI 5 or higher, temperature anomaly 0.9°C.
The Climate Central report used daily temperature data from ECMWF ERA5 (March 1 - May 28, 2024) and NOAA GFS (May 29 - 31, 2024) to calculate the Climate Shift Index (CSI). Population estimates based on the Gridded Population of the World v4 (2020) were used to determine global exposure to a CSI of 3 or higher.
The analysis covers 175 countries and territories, focusing on temperature anomalies, number of days at different CSI thresholds, and population exposure to CSI 5. The state-level analysis includes 84 states and territories in the U.S. and India with similar metrics.
Average temperature anomalies and the number of days at different CSI levels, including the CSI 5 threshold, were calculated for major cities (population over one million) and U.S. cities. The data
