Extreme heat waves in Africa could occur annually by 2045

London: Heat waves classified as unusual today could within 30 years become a normal yearly occurrence in Africa, thereby triggering a damaging effect on life expectancy and crop production in the continent -- one of the most vulnerable to climate change, say researchers.

This scenario could be triggered by an increase in average global temperature of two degrees, said the study that examined temperature data from 1979 to 2015.

"Africa is one of the most vulnerable continents to climate change and even a modest rise in average global temperature could have severe consequences for the people living there," said Jana Sillmann from Norway-based Centre for International Climate and Environmental Research (CICERO), one of the institutions taking part in the study. 

"We need to put considerable effort into climate change adaptation to reduce the risk of extreme events such as heat waves, which are likely to occur much more frequently in the future," Sillmann noted.

Results show that in the recent years Africa experienced hotter, longer and more extent heat waves than in the last two decades of the 20th century, the researchers noted.

"Unusual heat waves could occur every year across all seasons already by the year 2045 under the most severe scenario,” the study said.

The findings appeared in the journal Environmental Research Letters.

What is more, by running climate models through 2075, the scientists found that so-called unusual heat waves could occur as frequently as four times per year towards the end of the century. 

In other words, one dangerously hot spell for every season of the year.

To crunch the numbers, the team used a metric dubbed the Heat Wave Magnitude Index daily (HWMId). 

The data format takes into account the severity of the temperature extremes as well as the number of consecutive days of hot weather. 

Using this approach, the group compared heat waves occurring in different places and at different times of the year.