WASHINGTON: Human-caused climate change is causing more hot nights for nearly one in three people worldwide, according to a new global study released on Thursday.
High temperatures at night can be dangerous because they prevent our bodies from cooling down and recovering from daytime heat. The World Health Organisation (WHO) suggests keeping room temperatures at or below 24 degrees Celsius at night, as temperatures above this can make sleep uncomfortable. This is particularly important for vulnerable groups like babies, the elderly, and those with chronic health issues.
Also read: WHO: Extreme heat causes over 175,000 deaths annually in Europe
However, the burning of coal, oil, and gas, which releases greenhouse gases, is leading to more nights where temperatures stay above 25°C, says Climate Central, a group of climate scientists and communicators. Over the past decade, around 2.4 billion people have faced at least two extra weeks each year with nighttime temperatures not falling below 25°C.
Nick Obradovich, a chief scientist at the Laureate Institute for Brain Research, explained that warmer nights can disrupt sleep and hinder recovery from daytime heat, which can negatively impact health. This year has seen record-breaking heat, with extreme temperatures affecting regions from India to Saudi Arabia and Mexico, often staying high even at night.
The study compared the number of hot nights from 2014 to 2023 with what would have happened without human-induced climate change. This comparison used models based on historical data. For many countries, long-term data is incomplete, so researchers used an imagined world where carbon levels were different to see the impact of climate change.
Trinidad and Tobago saw the biggest increase, with 47 more hot nights each year, while Mumbai experienced an extra two months of hot nights. Obradovich noted that temperatures above 25°C aren’t an exact cutoff for health risks but generally, hotter nights are worse for health. High humidity combined with heat can be especially dangerous.
Also read: Millions of Indian crows facing death sentence in Kenya
Studies have shown that nights warmer than 25°C can worsen sleep quality, increase the risk of strokes, heart problems, and death. The elderly and people with lower incomes are particularly affected.
-Agencies
