(ORDO NEWS) — The world is warming and this threatens the habitability of many regions around the equator.
At this stage, even if we can limit global warming to 2 ˚C above pre-industrial levels, by 2100, the tropics and sub-tropics, including India, the Arabian Peninsula and sub-Saharan Africa, will experience dangerous heat.
At the same time, in the middle latitudes of the world, intense heat waves will be observed at least every year. In the US city of Chicago, for example, researchers predict a 16-fold increase in dangerous heat waves by the end of the century.
What are the chances that we will avoid this fate? About 0.1 percent, in terms of the projected probability that we will limit warming to below 1.5 ˚C above pre-industrial temperatures. In all likelihood, the researchers say, global warming will exceed 2 ˚C by 2050.
In this case, according to the researchers, “extremely dangerous heat stress will become a regular feature of the climate in sub-Saharan Africa, parts of the Arabian Peninsula and much of the Indian subcontinent.”
If the world fails to come together to take quick and wide-ranging adaptation measures, there will most likely be many deaths. But every bit we can lower the temperature still matters, because every fraction of a degree less heat will save lives.
According to the latest estimates, global warming is already responsible for one in three heat-related deaths worldwide.
Based on these numbers, other studies predict that people will die in record numbers in the coming decades as climate change shrinks our planet.
However, how people deal with heat stress is complicated by other factors, such as humidity. Modern estimates are based on a metric known as the heat index, which takes into account only relative humidity up to certain temperatures.
This is a traditional metric used by researchers to measure heat stress, however recent studies have shown that the human body may not be able to handle the amount of heat and moisture that this index shows.
Currently, 93 °C (200 °F) is considered the survival limit by the heat index.
But at 100 percent humidity, according to new research, even young and healthy people may not live past 31°C.
However, according to the traditional heat index, the temperature is considered dangerous if it exceeds 40 °C (103 °F), and extremely dangerous if it exceeds 51 °C.
It is these thresholds that were used in this study to predict future livability, and there is a strong possibility that they are an underestimation of what lies ahead.
However, even by these standards, the prospects for humanity look deplorable.
Between 1979 and 1998, the dangerous heat index threshold was exceeded in the tropics and subtropics on 15 percent of the days of the year.
During this time, the temperature rarely became extremely dangerous according to the heat index.
Unfortunately, the same cannot be said about today, and the problem is only getting worse.
By 2050, the dangerous heat index could be exceeded on 50 percent of the days of the year in tropical regions. By 2100, it may be exceeded on most days.
What’s more, about 25 percent of those days will be so hot that they exceed extremely dangerous thresholds.
“It is likely that without significant reductions in emissions in large parts of the global tropics and subtropics by the end of the century, the heat index will exceed the ‘danger’ level for most of the year,” the authors write.
“Without adaptation measures, this will significantly increase the incidence of heat-related illnesses and reduce outdoor performance in many areas where subsistence farming is important.”
The implications for health and society will no doubt be profound.
Contact us: [email protected]