The extreme June temperatures would have been ‘virtually impossible’ 50 years ago, says the World Weather Attribution group.

The historic heatwave gripping Europe is part of a dangerous weather trend that can only be explained by human-caused climate change, scientists have said.

The extreme temperatures sweeping across much of Europe mark the region’s “most severe” heatwave ever tracked for the month, and would have been “virtually impossible” half a century ago, the World Weather Attribution group of scientists said in a report released on Friday.

Millions in France, Italy, Spain, the United Kingdom and elsewhere in Europe have been experiencing blazing heat this week, with daytime temperatures topping 40 degrees Celsius (104 Fahrenheit) in many places.

The heatwave was reported on Friday to be moving eastwards, threatening Germany and central Europe with similar conditions to those which killed dozens in the western reaches of the continent, strained medical services and stressed the economy.

The World Weather Attribution estimated that a heatwave with similar characteristics occurring in the climate of June 1976 – when Europe was also hit by persistently high temperatures – would have been about 3.5 degrees Celsius cooler.

During another episode in 2003, temperatures would have been about 2 degrees Celsius cooler, the research suggests.

The analysis shows that intense heat is increasing rapidly, even within living memory, “with such events tens to hundreds of times more likely since only 2003 and virtually impossible just 50 years ago,” the study says.

“This event would not have been possible in June without climate change,” the study’s lead author, Theodore Keeping from Imperial College London, told reporters.

Phasing out fossil fuels ‘critical’

The planet has warmed about 1.4C above pre-industrial times, driven by the burning of coal, oil and gas.

Scientists agree this is making extreme weather events like heatwaves more frequent and intense, and that limiting warming is vital to avoid the worst impacts of climate change.

Of the nearly 850 cities the World Weather Attribution’s study analysed in Europe, some 45 percent had broken – or were expected to break – their all-time heat stress records in June.

“The weather pattern itself is not particularly unusual, but the temperatures are – or at least they used to be without human-induced climate change,” said Friederike Otto, the cofounder of World Weather Attribution.

The June heatwave in Europe is the second such episode this year. An early-season period of heat in May brought temperatures more typical of high summer to central and western parts of the continent.

World Weather Attribution said the rapid phase-out of fossil fuels is “critical if we are to avoid even higher temperatures and their consequences in the future”.