Extreme heat and droughts will be five times more frequent by the end of the century

The two events (drought and extreme heat) together generate greater risks than each one alone, and threaten food security, human health and access to water, in addition to emphasizing the “profound climate injustice”, since countries with fewer resources to adapt will suffer the most severe consequences of the emissions generated by industrial powers.

These are the main conclusions of a study carried out by researchers from the Oceanic University of China and the German Alfred Wegener Institute, which have observed how conditions could evolve until the end of the century and have carried out 152 simulations based on eight climate modelsconsidering various scenarios of population growth and global warming described in the Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC).

The researchers published the results of their work today in the journal Geophysical Research Letters, of the American Geophysical Union.

The analysis suggests that Complying with international emissions agreements could significantly reduce the number of people exposed to these environmental hazardsand that current political decisions will determine the quality of life and survival of billions of people in the coming decades.

Researchers have highlighted that heat and drought enhance each other, and in extreme situations lead to water restrictions and instability in food prices, as well as an increased risk of forest fires, agricultural losses and increased mortality.

The researchers divided the Earth’s surface into cells on a grid and compared the frequency of heat waves and droughts in each cell, and found that land areas experienced approximately four heat and drought events per year between 2001 and 2020, which is twice the frequency recorded in the pre-industrial period, between 1850 and 1900.

And although they have pointed out that the more chaotic the climate becomes, the more difficult it is to make forecasts, scientists have corroborated that in the climate and demographic growth scenario most in line with the current trajectory, extremes of heat and drought would intensify for 28 percent of the world’s population — almost 2.6 billion people — by the 2090s, and 6.6 percent will suffer that level of exposure in the 2030s.

Globally, combined heat and drought extremes could occur nearly 10 times a year on average by the end of the century, with the longest lasting around 15 days, representing a 2.4- and 2.7-fold increase over conditions over the past 25 years, respectively.

Researchers have concluded that it is human greenhouse gas emissions that are driving these changessince when they analyzed simulations considering only natural forces, no significant trends were observed in the frequency or duration of extremes of heat and drought.

They have also concluded that the countries that emit the most will not be the ones that suffer the greatest impacts, and based on the geographical distribution of risk in the simulations, low-income nations near the equator and the tropics will experience the most intense extremes of heat and drought despite contributing far fewer emissions than richer nations.