India, the Arabian peninsula and sub-Saharan Africa will experience dangerously hot temperatures most days of the year by 2100 even if global warming is limited to 2 ˚C above pre-industrial levels, says new Data and estimates.
The new analysis said that mid-latitudes of the world would experience intense heat waves each year at least. In the United States city of Chicago, for instance, researchers predict a 16-fold increase in dangerous heat waves by the end of the century.
The researchers in the study published in Communications Earth & Environment, said “extremely dangerous heat stress will be a regular feature of the climate in sub-Saharan Africa, parts of the Arabian peninsula, and much of the Indian subcontinent”.
HOT TEMPERATURES; DEATHS
The researchers maintain that the world would witness more deaths if wide spread measures are not implemented to bring down the temperature. “But every bit we can reduce temperatures by still matters, because every fraction of a degree of less heat will save lives. Recent estimates suggest global warming is already responsible for one in three heat-related deaths globally,” they said.
HOT TEMPERATURE; HUMIDITY
Noting that dealing of heat stress is complicated by other factors, like humidity, the authors said that the present estimates are based on a metric known as the Heat Index, which only takes into account relative humidity up to certain temperatures. They point out that recent studies have found the human body might not be able to cope with as much heat and humidity as this index indicates.
“As it stands, 93 °C (200 °F) on the Heat Index is considered the ceiling of what is survivable. But at 100 percent humidity, new research suggests even young and healthy people may not live past 31 °C. Nevertheless, on the traditional Heat Index, temperatures are considered dangerous when they exceed 40 °C (103°F) and extremely dangerous when they exceed 51 °C,” they said.
These are the thresholds the current study used to predict habitability in the future, and there’s a good chance they are an underestimation of what is to come.
Even by this measure, however, humanity’s prospects look dire.
Between 1979 to 1998, the dangerous Heat Index threshold was exceeded in the tropics and subtropics on 15 percent of the days each year, they noted.
HOT TEMPERATURE; HEAT INDEX
By 2050, in tropical regions, the researchers say that Heat Index could be exceeded on 50 percent of the days each year. By 2100, it could be exceeded on most days.
What’s more, about 25 percent of those days could be so hot, they could exceed extremely dangerous thresholds.
“It is likely that, without major emissions reductions, large portions of the global tropics and subtropics would experience Heat Index levels higher than considered ‘dangerous’ for a majority of the year by the end of the century,” the authors write.
“Without adaptation measures, this would greatly increase the incidence of heat-related illnesses and reduce outdoor working capacity in many regions where subsistence farming is important.”
Every country is likely to experience extremely hot years every other year by 2030, said a group of researchers in their new study. In the study published in the journal Communications Earth and Environment, the researchers claimed that 92 per cent of 165 countries that they looked into are expected to experience extremely hot annual temperatures every two years.