Projected increase in droughts over the Arabian Peninsula and associated uncertainties

Area of Science:

• Climate Science
• Environmental Science
• Earth System Science

Background:

• The Arabian Peninsula (AP) faces increasing drought frequency.
• Global Climate Models (GCMs) are crucial for understanding climate change impacts.

Purpose of the Study:

• Evaluate CMIP6 GCMs for historical drought simulation and future projections in the AP.
• Assess uncertainties in drought projections across different models, scenarios, timescales, and methods.

Main Methods:

• Utilized the standardized precipitation index (SPI) and standardized precipitation-evapotranspiration index (SPEI).
• Assessed Climate Model Intercomparison Project 6 (CMIP6) Global Climate Models (GCMs).
• Employed Hargreaves method for potential evapotranspiration (PET) calculation.

Main Results:

• Most CMIP6 GCMs struggle to accurately reproduce historical precipitation, impacting SPI projections.
• CMIP6 GCMs show better performance in capturing increased potential evapotranspiration (PET), improving SPEI projections.
• Projected PET increase is fivefold greater than precipitation increase across all scenarios.
• SPEI indicates escalating future droughts, particularly under SSP585 and SSP370 scenarios.

Conclusions:

• Drought conditions are projected to worsen across the AP, irrespective of model and scenario uncertainties.
• The SPEI is a more reliable indicator of future drought trends in the AP than SPI.
• Improved representation of AP precipitation in climate models is essential for accurate drought projections and adaptation planning.