Sweltering temperatures are shattering records across Europe, as the continent battles a deadly heatwave.

On Tuesday and Wednesday, France endured its hottest days in history, with western regions reaching highs of between 39°C and 43°C. Wednesday was the United Kingdom’s warmest June day on record, with the mercury climbing to 36.1°C. And according to early data, Spain, Germany, Austria, the Netherlands and Switzerland have all broken June temperature records at several sites. And the event is not over yet.

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Tragically, lives have already been lost, including dozens of people who have drowned in France in the past week, while trying to cool down in the punishing heat.

But this historic heatwave is not happening in isolation. It comes days after the global sea surface temperature again reached record levels. Meanwhile, Australia’s weather bureau has declared El Niño active, making a hotter, drier year in Australia, Asia and the South Pacific much more likely. And since April, India and Pakistan have been battling a sustained and ultimately deadly heatwave.

So what’s driving this latest heatwave? And why is it so severe?

A heatwave occurs when the average temperature is unusually hot for three or more days in a row. That’s compared to past weather data taken from the same location.

But scientists are losing sleep over the current European........

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