El Nino-driven sea surface temperatures reached hottest-ever in July

In July, global sea surface temperatures reached an all-time high, largely due to the El Nino phenomenon, according to the EU's Copernicus climate change agency. The intense heat led to devastating wildfires in western Europe, consuming over 500,000 hectares of land this summer, marking the worst year on record. The average temperature in western Europe during June-July reached a record 21.62°C, a staggering 2.79°C above the norm, surpassing the previous peak set in 2022.

The prolonged heat was accompanied by an alarming lack of rainfall and soil moisture, particularly in France, Spain, parts of Germany, and the UK. Samantha Burgess, the strategic lead for climate at the European Centre for Medium-Range Weather Forecasts, noted that three consecutive months of extreme heat in western Europe had pushed the combined temperature for June and July to a new high.

Persistent high-pressure systems trapped heat over the region, exacerbating the record-breaking temperatures. Air quality expert Laurence Rouil of Copernicus Atmosphere Monitoring Services reported that the massive fires were spreading northward, releasing more smoke higher into the atmosphere, which could travel further and affect air quality in regions thousands of kilometers away.

This smoke could impact countries with relatively fewer wildfires. The extreme heat also caused lower-than-average river flows in Europe's major rivers, such as the Seine, Rhine, and Danube, disrupting water supply and energy production. In Hungary, residents were urged to reduce electricity consumption due to low water levels in the Danube, impacting the Paks nuclear plant.

Conversely, some areas of Europe experienced heavier rainfall than usual, leading to localized flooding. While some regions, like the Baltic States, Turkey, Greece, eastern Ukraine, and western Russia, faced flooding, others saw wildfires. For instance, thousands of hectares of farmland near a popular holiday resort north-west of Athens were consumed last week.

El Nino, a periodic warming of ocean surface temperatures in the Pacific, could push nearly 49 million people in vulnerable regions into acute food insecurity by the end of next year, according to the World Food Programme. In July, the average sea surface temperature hit 20.97°C, beating the previous July record of 20.89°C, set in 2023.

These unusually high temperatures are expected to persist across a vast area of the tropical Pacific, where El Nino conditions are likely to intensify in the coming months. Additionally, exceptionally high sea temperatures were recorded along the Atlantic coast and the western Mediterranean, linked to widespread strong or severe marine heatwaves impacting coastal ecosystems and communities.