GENEVA: Periods of extreme heat are becoming more frequent, more intense and longer-lasting as climate change warms the planet, the UN weather agency said on Tuesday — and it made the point by reaching back to the famously hot European summer of 1976.

Parts of Europe are currently enduring their fifth heatwave of a summer already marked by drought, wildfires and record-breaking temperatures.

“Extreme heat is becoming more frequent, more intense, it’s lasting longer, and covering much wider areas than in the cooler climates of the past,” John Kennedy, head of climate information at the World Meteorological Organisation, told a press briefing in Geneva.

Kennedy said the current heat pattern across Europe — the world’s fastest-warming continent — reflects the interaction between a persistent pattern of high-pressure systems across the Northern Hemisphere and a warmer underlying climate. High-pressure systems trap warm air, reduce cloud cover and block cooler air from moving in, allowing heat to build across large regions for days or weeks at a time.

Notably, El Niño is not a factor this year. The naturally occurring pattern that typically boosts global temperatures is not contributing to Europe’s heat, Kennedy said, because conditions in the tropical Pacific are currently neutral — meaning the heat is arriving without that additional push.

The 1976 comparison is where the argument lands. Kennedy said June 1976 featured a broadly similar arrangement of high and low pressure systems to this year’s. The outcomes, however, are entirely different because of decades of accumulated warming since.

“The picture for 1976 is one of a few isolated areas above average temperatures in a much cooler world,” he said. Today, “the picture is reversed” — most of the globe is running above average, with only a few isolated cooler regions left.