How climate change is impacting your night's sleep
As India continues to reel under a severe heatwave, a new analysis shows climate change has added approximately 50 to 80 nights each year where the temperature exceeded 25°C, with serious impacts on sleep and health
- Jun 21, 2024,
- Updated Jun 21, 2024 1:18 PM IST
This summer, the temperature during the day has touched 50 degree Celsius in several cities, but what is more worrying is temperatures increasing even more rapidly during the night, according to an analysis by Climate Central and Climate Trends.
The new analysis shows approximately 50 to 80 days each year were added above the 25 degree Celsius threshold by climate change in cities across Kerala, Karnataka, Maharashtra, Tamil Nadu, Punjab, Jammu and Kashmir, and Andhra Pradesh, between 2018 and 2023. Among the metro cities, Mumbai has seen the biggest changes in the night-time temperatures, with the city experiencing an additional 65 days of warmer nights due to global warming.
The eastern and northeastern states were hit the most by rising night temperatures. West Bengal and Assam are the regions that have been most impacted, with cities like Jalpaiguri, Guwahati, Silchar, Dibrugarh, and Siliguri experiencing between 80 and 86 additional days each year above the threshold due to climate change, on average.
Dr Roxy Mathew Koll, Climate Scientist, Indian Institute of Tropical Meteorology, Pune says, “The urban heat island effect is most visible in night-time temperatures. Cities turn into urban heat islands when buildings, roads, and other infrastructure absorb and re-emit heat, causing them to be several degrees hotter than the surrounding rural areas. Climate change is aggravating the heat everywhere but the urban heat islands that trap this heat are our construction.”
Higher nighttime temperatures can cause physiological discomfort and impact human health by preventing body temperature from cooling off during the night, increasing mortality risks. There is also growing evidence that as night-time temperatures rise, it is adversely affecting the quality and length of sleep as well.
“The rise in nighttime temperatures due to climate change poses a severe threat to the vulnerable populations. The inability to cool down at night can lead to chronic sleep deprivation, further weakening immune systems and increasing susceptibility to illness. For marginalised communities who already face hardships, this added climate stress can be devastating,” says Prof Anjal Prakash - Clinical Associate Professor (Research) and Research Director, Bharti Institute of Public Policy, Indian School of Business.
These findings came on a week that saw new records for nighttime heat in several Indian cities. On June 19, Delhi shattered the all-time high minimum temperature record, with the mercury reaching 35.2°C over night. Delhi recorded almost four additional nights over 25°C due to climate change between 2018 and 2023, according to the Climate Central analysis.
“Climate change has a big role as a constant rise in global temperatures has also increased air temperature impacting both day and night temperatures. Clear sky paves the way for cooling during night time, but with an increase in pollution or cloudy sky, the energy emitted by the earth in the form of longwave radiation is trapped between the base of the cloud and the earth’s surface leading to a further rise in temperature,” said Mahesh Palawat, Vice President – Meteorology and Climate Change, Skymet Weather.
This summer, the temperature during the day has touched 50 degree Celsius in several cities, but what is more worrying is temperatures increasing even more rapidly during the night, according to an analysis by Climate Central and Climate Trends.
The new analysis shows approximately 50 to 80 days each year were added above the 25 degree Celsius threshold by climate change in cities across Kerala, Karnataka, Maharashtra, Tamil Nadu, Punjab, Jammu and Kashmir, and Andhra Pradesh, between 2018 and 2023. Among the metro cities, Mumbai has seen the biggest changes in the night-time temperatures, with the city experiencing an additional 65 days of warmer nights due to global warming.
The eastern and northeastern states were hit the most by rising night temperatures. West Bengal and Assam are the regions that have been most impacted, with cities like Jalpaiguri, Guwahati, Silchar, Dibrugarh, and Siliguri experiencing between 80 and 86 additional days each year above the threshold due to climate change, on average.
Dr Roxy Mathew Koll, Climate Scientist, Indian Institute of Tropical Meteorology, Pune says, “The urban heat island effect is most visible in night-time temperatures. Cities turn into urban heat islands when buildings, roads, and other infrastructure absorb and re-emit heat, causing them to be several degrees hotter than the surrounding rural areas. Climate change is aggravating the heat everywhere but the urban heat islands that trap this heat are our construction.”
Higher nighttime temperatures can cause physiological discomfort and impact human health by preventing body temperature from cooling off during the night, increasing mortality risks. There is also growing evidence that as night-time temperatures rise, it is adversely affecting the quality and length of sleep as well.
“The rise in nighttime temperatures due to climate change poses a severe threat to the vulnerable populations. The inability to cool down at night can lead to chronic sleep deprivation, further weakening immune systems and increasing susceptibility to illness. For marginalised communities who already face hardships, this added climate stress can be devastating,” says Prof Anjal Prakash - Clinical Associate Professor (Research) and Research Director, Bharti Institute of Public Policy, Indian School of Business.
These findings came on a week that saw new records for nighttime heat in several Indian cities. On June 19, Delhi shattered the all-time high minimum temperature record, with the mercury reaching 35.2°C over night. Delhi recorded almost four additional nights over 25°C due to climate change between 2018 and 2023, according to the Climate Central analysis.
“Climate change has a big role as a constant rise in global temperatures has also increased air temperature impacting both day and night temperatures. Clear sky paves the way for cooling during night time, but with an increase in pollution or cloudy sky, the energy emitted by the earth in the form of longwave radiation is trapped between the base of the cloud and the earth’s surface leading to a further rise in temperature,” said Mahesh Palawat, Vice President – Meteorology and Climate Change, Skymet Weather.