London: A new study by the University of Oxford has delivered a stark warning on the future of global heat exposure, projecting that nearly half of the world’s population could be living under extreme heat conditions by 2050 if global temperatures rise by 2°C above pre-industrial levels. That scenario, once considered avoidable, is now seen by many climate scientists as increasingly likely.
The research estimates that around 3.79 billion people would be exposed to dangerously high temperatures within the next 25 years, marking a dramatic shift from 2010, when about 23 percent of the global population lived in extreme heat zones. By mid-century, that figure is expected to climb to 41 percent.
The study highlights that the most severe changes will arrive sooner rather than later, as the world moves past the 1.5°C target set under the Paris Agreement. Even before reaching 2°C, the growth in extreme heat exposure is expected to accelerate, placing pressure on health systems, education, labour productivity, and food security.
Some of the sharpest increases in dangerously hot conditions are projected for countries such as the Central African Republic, Nigeria, South Sudan, Laos, and Brazil. In terms of sheer numbers, the largest affected populations are expected to be in India, Nigeria, Indonesia, Bangladesh, Pakistan, and the Philippines, where heat exposure intersects with dense populations and existing vulnerabilities.
The findings also underline how warming reshapes energy needs in traditionally colder countries. Between a 1°C and 2°C warming scenario, heating demand is projected to fall sharply across northern regions.
Canada is expected to see the steepest decline in heating degree days, followed by Russia, Finland, Sweden, Norway, and the United States. While reduced heating needs may lower energy costs, researchers caution that infrastructure designed for cold climates may struggle to cope with rising summer temperatures, leading to disproportionate impacts.
As extreme heat spreads, demand for cooling is set to rise rapidly, driving higher electricity consumption and potentially increasing emissions if energy systems do not decarbonise quickly. Many homes, particularly in regions unaccustomed to sustained heat, may require air conditioning within the next few years, even as temperatures continue climbing beyond that point.
The study stresses that overshooting 1.5°C would have far-reaching consequences, influencing migration patterns, agricultural productivity, and public health worldwide. Researchers argue that net-zero, sustainable development remains the only proven pathway to reversing the trend of ever hotter days.
To support planning and policy, the study also introduces an open-source global dataset mapping heating and cooling demand at high resolution. By translating climate change into practical measures of human comfort and energy needs, the research offers governments a clearer view of what a hotter world will demand and how urgently adaptation and mitigation must begin.
