Yeah it's true, Europe has had heat waves in the past. For instance, in 1540. Also 1779. And also 1906, 1947, 1964, 1976, 2003, 2006, 2015, 2017, 2018, 2019, 2020, 2022, 2023, 2024, and 2025.
I have not read that article, but I was aware Arrhenius calculated the effects of CO2 on global temperatures earlier. AFAIK his models has held up very well, possibly because of its simplicity compared to current models (I tend to distrust complex models).
These are 20 year periods, not decades. How did you think there were 13 years in the previous decade? It would be 18 vs 13 if every year up to 2039 went over 30C.
Why don't you research past heat waves? We're literally setting new heat records nearly every year. This year the heat record in Germany went from 39 degrees to 42. We're even setting night time heat records because of how bad it is. I don't understand the impulse to ignore what we're experiencing right now. What do you gain by sticking your head in the sand?
Ask your grandparents about "Die große Dürre 1947" in Germany. Near entirely dried-up rivers and reservoirs, lakes three meters below normal, roughly half a million cattle emergency-slaughtered in Bavaria, hydroelectric shutdowns forcing power rationing, and forest fires along the Bavarian–Austrian border.
Sure we have an all time high now, but currently there's still too much water as one could stick their head into the soil of the Elbe and Rhine.
That used to be once in a lifetime event. Now we have temperatures like that two or three times every decade and soon it's going to be a normal summer temperature.
Frequency? Do I look like a statistician to you?!