The world’s temperatures continue to rise at an alarming pace, and new research from Oxford University has issued a stark warning: by 2050, citizens of six countries—including Bangladesh—will be living under extreme heat conditions. The consequences of such intense heat are far-reaching, posing severe risks to ecosystems, economies, and public health systems alike.
Led by climate and population experts at Oxford, the study was published on 26 January in the journal Nature Sustainability. Its preliminary findings indicate that if the current reliance on fossil fuels persists, the number of people exposed to extreme heat globally could nearly double over the next 25 years. Specifically, if global warming exceeds pre-industrial levels by 2°C, nearly 41% of the world’s population—approximately 3.79 billion people—could face hazardous heat conditions by mid-century. In comparison, in 2010, around 23% of people, or 1.54 billion, were similarly at risk.
The researchers utilised the “Cooling Degree Days” (CDD) index, which measures the amount of cooling required to maintain safe indoor temperatures. Regions registering an annual CDD of more than 3,000 are classified as highly heat-prone.
The six nations projected to experience extreme heat by 2050, along with their expected exposure levels, are as follows:
| Rank | Country | Annual CDD | Population at Risk (millions) |
|---|---|---|---|
| 1 | India | >3000 | 1050 |
| 2 | Nigeria | >3000 | 210 |
| 3 | Indonesia | >3000 | 320 |
| 4 | Bangladesh | >3000 | 165 |
| 5 | Pakistan | >3000 | 220 |
| 6 | Philippines | >3000 | 120 |
Dr. Jesús Lizana, the study’s lead researcher, emphasised the hidden nature of the threat: “National average temperatures often obscure real risk. In Bangladesh, a significant portion of the population lives in areas where annual CDD exceeds 3,000, meaning prolonged exposure to dangerously high heat that can severely impact life, productivity, and health.”
The research highlights that the rise in extreme heat will significantly increase the incidence of heatstroke, cardiovascular stress, and kidney disease. Vulnerable groups—particularly the elderly, children, and low-income communities—are likely to suffer the most, given their limited access to cooling.
The study also warns of the “cooling trap”: excessive use of air conditioning powered by fossil fuels could exacerbate climate change. Scientists stress that limiting global warming to 1.5°C above pre-industrial levels could drastically reduce the number of people exposed to lethal heat conditions, mitigating the most severe consequences for human health and livelihoods.