The world is on the brink of a heatwave crisis, with a staggering 3.79 billion people expected to experience extreme heat by 2050 if global temperatures rise by 2C. This is according to a groundbreaking study that reveals how energy demands for air conditioning and heating systems will shift across the globe. The research, published in Nature Sustainability, provides a detailed insight into the impact of rising temperatures on different regions, highlighting the urgent need for adaptation measures. The study defines extreme heat as days when temperatures deviate from a temperate baseline of 18C. Using computer models, the authors mapped the regions most affected and the number of people at risk. The findings are alarming, with the number of people exposed to extreme heat set to increase from 1.54 billion (23% of the world population in 2010) to a staggering 3.79 billion (41% of the projected population in 2050) if the 2C threshold is breached. The majority of those affected will be in India, Nigeria, Indonesia, Bangladesh, Pakistan, and the Philippines. However, the most significant increase in dangerous temperatures will threaten Central African Republic, Nigeria, South Sudan, Laos, and Brazil. Surprisingly, the study found that the greatest shift will occur early in the warming trajectory, near the 1.5C phase, which is where the world currently stands. This urgent finding emphasizes the need for immediate action to support adaptation and mitigation measures in sectors like healthcare, the economy, and the energy system. Radhika Khosla, one of the authors, emphasizes the criticality of the situation, stating that overshooting 1.5C of warming will have unprecedented impacts on various aspects of life, from education and health to migration and farming. She stresses the importance of politicians taking the initiative towards net zero sustainable development to reverse the trend of ever-hotter days. Even relatively wealthy, northern nations will struggle to cope with extreme heat, as their infrastructure is not adequately prepared. The UK, for instance, faces challenges due to its old, inefficient buildings and infrastructure designed for colder climates. In 2023, the UK National Grid had to activate coal-fired power plants to meet air conditioning demand during an unusual heatwave, highlighting the urgent need for adaptation and the potential consequences of inaction.
