Higher temperatures have increased drought frequency and intensity over the last two decades, but the trend could be reversed in the next 20 years.

A study of 70 years of climate data has examined distinct drought patterns across the Arabian Peninsula — one of the driest regions in the world. Led by KAUST’s Ibrahim Hoteit, the team analysed climate data from 1951 to 2020 to map the long-term variability of droughts and explore the factors driving these changes. “Understanding historic and future drought trends in the Arabian Peninsula is crucial for water resource management in agriculture and urban development,” says Hoteit.

The researchers used the Standardized Precipitation Evapotranspiration Index (SPEI), which considers both rainfall and temperature data. “Droughts are typically measured using the Standardized Precipitation Index (SPI), but in arid regions like the Arabian Peninsula, relying on rainfall alone is insufficient,” says climate change researcher and study author Md Saquib Saharwardi.

The study outlines four distinct drought regions across the Arabian Peninsula, each exhibiting unique seasonal drought variability. However, the KAUST team found that, overall, droughts have worsened over the past two decades, not because of a decrease in rainfall, but rather due to rising temperatures.

To predict future droughts, Hoteit and colleagues developed a machine learning approach that considers the Atlantic Multidecadal Oscillation (AMO), a 70-year cyclical phenomenon of the Atlantic’s sea surface temperature that significantly affects the region’s climate. Interestingly, their model predicts a decrease in drought severity as the AMO shifts from a positive to a negative phase.

“During the positive phase of the AMO, droughts tend to worsen, while the negative phase leads to a reduction in droughts,” Saharwardi explains. “Our machine learning model predicts a substantial decrease in droughts over the next 20 to 30 years, coinciding with the expected negative phase of the AMO.”

Learn more at KAUST Discovery.