Countries in the tropics could face extreme temperature swings due to global warming, according to new research. In a study examining how climate change will impact weather extremes including heat waves and cold spells, researchers found that the world’s poorest regions are expected to experience increased temperature variability, while many wealthier nations will likely see less variation.
The study was carried out by team of researchers from the University of Exeter in the UK, Wageningen University in the Netherlands and the University of Montpellier in France. The team published their findings on Wednesday in the journal Science Advances.
To determine which regions would experience greatest temperature variability through the year 2100, researchers analysed 37 different climate models used by the United Nations Intergovernmental Panel on Climate Change (IPCC) in its latest report.
The analysis showed that increased temperature fluctuations would be concentrated in the tropics, with higher latitudes experiencing a decrease in temperature variability. According to the study, temperature variability could increase by as much as 15% in the Amazon Basin and southern Africa for each degree Celsius of global warming, and by up to 10% in India, Southeast Asia and the Sahel region of western and north-central Africa.
Researchers said the disparity could be explained by the ways temperatures are moderated in different latitudes. Temperature swings in the tropics are partially controlled by soil moisture, lead author Dr Sebastian Bathiany of Wageningen University told NPR. But rising temperatures can dry out the soil, thereby reducing its ability to mitigate fluctuations. In contrast, temperature variation in higher latitudes including the United States and Europe is driven largely by atmospheric weather patterns.
The findings represent an “unfair pattern,” according to researchers, since many of the countries expected to be most severely affected by climate change are among the world’s poorest nations.
“The countries that have contributed least to climate change, and have the least economic potential to cope with the impacts are facing the largest increases in temperature variability,” Bathiany said in a press release.
Such changes in temperature variability would “amplify the inequality associated with the impacts of a changing climate,” the authors wrote in their paper.
“The countries affected by this dual challenge of poverty and increasing temperature variability already share half of the world’s population, and population growth rates are particularly large in these countries,” added study co-author Professor Tim Lenton, from the University of Exeter. “These increases are bad news for tropical societies and ecosystems that are not adapted to fluctuations outside of the typical range.”
The authors noted, however, that Australia is an exception – it is one of the only wealthy countries with high per capita greenhouse gas emissions where temperature variability is expected to increase.
The findings add to the growing body of research suggesting that climate change will bring more extreme weather events. A recent report from the European Academies’ Science Advisory Council cites data indicating that events such as floods and droughts have increased since the 1980s, while another new study warned that the state of California in the US will likely experience more extreme wet and dry periods over the next 100 years.