Climate change will sharply boost the frequency of lethal heatwaves even if humanity caps global warming at two degrees Celsius (3.6 degrees Fahrenheit), the core goal of the Paris Agreement, scientists said
Even 2C warming means more killer heatwaves: study: Fulfilling that 196-nation pledge would, by 2100, still leave nearly half the world's population exposed at least once a year to bouts of heat and humidity that have proven deadly in the past, they reported in the journal Nature Climate Change.
Under a "business-as-usual" scenario, in which greenhouse gases continue pouring into the atmosphere at current rates, three-quarters of humanity will annually face what the researchers call "lethal heat events."
"We found that killer heatwaves around the world are becoming more common, and that this trend already seems unavoidable," said Camilo Mora, a professor at the University of Hawaii and lead author of the study.
"Even if we outperform the Paris targets, the population exposed to deadly heat will be about 50 percent by 2100," he told AFP.
Already today, 30 percent of Earth's inhabitants encounter super hot spells at some point in the year.
Since the start of the 21st century, heatwaves have claimed tens of thousands of lives, even in countries best equipped to help their citizen cope. In western Europe, for example, there were more than 70,000 excess death during the blistering summer of 2003.
In future, the tropics will be hit hardest, according to the study, which forecasts -- year-by-year, for each square kilometre on Earth -- the number of "deadly days" under three different carbon pollution scenarios laid out by the UN Intergovernmental Panel for Climate Change (IPCC)."
Under a "business-as-usual" scenario, in which greenhouse gases continue pouring into the atmosphere at current rates, three-quarters of humanity will annually face what the researchers call "lethal heat events."
"We found that killer heatwaves around the world are becoming more common, and that this trend already seems unavoidable," said Camilo Mora, a professor at the University of Hawaii and lead author of the study.
"Even if we outperform the Paris targets, the population exposed to deadly heat will be about 50 percent by 2100," he told AFP.
Already today, 30 percent of Earth's inhabitants encounter super hot spells at some point in the year.
Since the start of the 21st century, heatwaves have claimed tens of thousands of lives, even in countries best equipped to help their citizen cope. In western Europe, for example, there were more than 70,000 excess death during the blistering summer of 2003.
In future, the tropics will be hit hardest, according to the study, which forecasts -- year-by-year, for each square kilometre on Earth -- the number of "deadly days" under three different carbon pollution scenarios laid out by the UN Intergovernmental Panel for Climate Change (IPCC)."
