How is the hot summer in Europe indicative of a long-term climate change more than Donald Trump saying "see, it's snowing outside! I told you there's no climate change!"
The extent of the heatwaves is the difference. I saw a map showing that basically the whole world has above average temperatures this summer - past heat waves tended to be local. Much like a local record snowfall.
You have a point, I could have qualified my post with an 'if these hot temperatures continue in Europe' to hedge since the effects of climate change don't necessarily appear as super-linear phenomenon - there is scope for significant variation.