Rising ocean temperatures increase extreme weather risks in Türkiye

Sea surface temperatures in April 2026 approached record levels globally, with oceans outside polar regions averaging 21 degrees Celsius—the second-highest level ever recorded—while Arctic sea ice coverage hit its second-lowest April level, according to Copernicus Climate Change Service data. Cem Gazioğlu, director of Istanbul University’s Institute of Marine Sciences and Management, warned that these trends, combined with potential El Niño development later this year, will intensify extreme weather risks in Türkiye, including marine stress events, coastal flooding, and storm surges. Gazioğlu emphasized that oceans now play a central role in shaping global weather extremes, with rising temperatures increasing upper ocean heat content and strengthening atmospheric moisture transfer. This interaction heightens the frequency and intensity of storms, extreme rainfall, prolonged heatwaves, and droughts, particularly in mid-latitude regions like Türkiye. The Eastern Mediterranean, described as a ‘climate change hot spot,’ faces elevated risks of ‘medicanes’—intense Mediterranean cyclones—due to warming sea surface temperatures. In Türkiye, prolonged sea surface temperature anomalies along the Aegean and Mediterranean coasts are altering marine ecosystems, accelerating invasive species spread, and disrupting species distribution. Meanwhile, the Black Sea Basin has seen severe floods and landslides linked to changing atmospheric moisture systems, while mucilage formation in the Marmara Sea is tied to temperature anomalies and nutrient loads. Coastal erosion in the Black Sea is worsening due to intense rainfall-driven sediment transport, and short but heavy downpours around Istanbul are increasing urban flooding risks. Central and southeastern Türkiye are experiencing worsening meteorological and hydrological droughts, compounding climate-related threats. Gazioğlu urged rapid expansion of high-resolution climate observation networks and continuous monitoring to mitigate these risks, highlighting the urgent need for adaptive strategies in vulnerable coastal and inland regions.