Dhaka, May 31 -- About half of the world's population experienced an additional month of extreme heat over the past year due to human-caused climate change, according to a new study.The extreme heat caused deaths and illnesses, damaged agricultural crops and strained energy and healthcare systems, according to the report (pdf) from World Weather Attribution, Climate Central and the Red Cross published on Friday.Researchers analysed weather data from May 1, 2024 to May 1, 2025 to spotlight the dangers of extreme heat, which was defined as hotter than 90 percent of temperatures recorded at a given location between 1991 and 2020.It found that about four billion people, or 49 percent of the world's population, experienced at least 30 days of ex...