Human-induced climate change compounded by socio-economic water stressors increased severity of 5-year drought in Iran and Euphrates and Tigris basin

A super-rapid attribution study by World Weather Attribution finds that human-induced climate change has significantly increased the likelihood and intensity of a five-year drought in Iran and the Tigris-Euphrates basin. The analysis shows that while low-rainfall years are natural to the region, the current 'extreme' to 'exceptional' drought conditions would have been very rare in a pre-industrial climate. The study highlights that warming increases evaporative demand, prolonging droughts and compounding the effects of socio-economic stressors like unsustainable groundwater extraction and water-intensive agriculture.

• Human-induced climate change has significantly increased the probability of the five-year drought in Iran. A drought of this severity (SPEI-60) has a return period of approximately 5 years in the current climate but would have been a 1-in-~250 year event in a pre-industrial climate, making it approximately 50 times more likely due to 1.3°C of warming.
• Climate change has shifted the classification of the five-year drought from 'normal' conditions to 'extreme' (D3) in Iran and 'exceptional' (D4) in the Tigris-Euphrates basin. Without human-caused climate change, the current combination of rainfall and temperatures would not be classified as a drought.
• The drought has caused severe water scarcity and agricultural failure across West Asia. In Iraq, 2025 was the driest year since 1933, with Tigris and Euphrates water levels falling by up to 27%. In Syria, rainfall dropped by nearly 70%, affecting 75% of rain-fed farmland and creating a wheat shortfall of 2.73 million tonnes.
• Socio-economic factors have compounded the climate-driven water crisis in Iran. These include water-intensive agriculture, which consumes over 90% of the country's water, unsustainable groundwater extraction, and rapid land-use changes such as overgrazing and agricultural expansion that accelerate soil degradation.
• The study indicates that global warming is not only making droughts more frequent but also more prolonged. The probability ratio for the five-year drought is higher than that found in a previous 2023 study of a three-year drought, suggesting a trend toward longer-duration events.
• While there is an emerging decreasing trend in annual and five-year accumulated rainfall totals associated with global mean surface temperature, the changes are small and uncertainties encompass no change, meaning the study refrains from a quantitative assessment of climate change's role in rainfall lows.

APA

World Weather Attribution (2025). Human-induced climate change compounded by socio-economic water stressors increased severity of 5-year drought in Iran and Euphrates and Tigris basin. https://www.worldweatherattribution.org/human-induced-climate-change-compounded-by-socio-economic-water-stressors-increased-severity-of-5-year-drought-in-iran-and-euphrates-and-tigris-basin/

Chicago

World Weather Attribution. Human-induced climate change compounded by socio-economic water stressors increased severity of 5-year drought in Iran and Euphrates and Tigris basin. 2025. https://www.worldweatherattribution.org/human-induced-climate-change-compounded-by-socio-economic-water-stressors-increased-severity-of-5-year-drought-in-iran-and-euphrates-and-tigris-basin/.

Wikipedia

{{cite report |author=World Weather Attribution |title=Human-induced climate change compounded by socio-economic water stressors increased severity of 5-year drought in Iran and Euphrates and Tigris basin |date=21 November 2025 |url=https://www.worldweatherattribution.org/human-induced-climate-change-compounded-by-socio-economic-water-stressors-increased-severity-of-5-year-drought-in-iran-and-euphrates-and-tigris-basin/ |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{worldweatherattribution2025humaninduced, author = {{World Weather Attribution}}, title = {{Human-induced climate change compounded by socio-economic water stressors increased severity of 5-year drought in Iran and Euphrates and Tigris basin}}, institution = {World Weather Attribution}, year = {2025}, month = nov, url = {https://www.worldweatherattribution.org/human-induced-climate-change-compounded-by-socio-economic-water-stressors-increased-severity-of-5-year-drought-in-iran-and-euphrates-and-tigris-basin/}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }