In the mid 90s, I did my PhD in Essen, a city in the Rhine-Ruhr-Area (Germany). Back then, I was working on man made precipitation modifications in urban areas. Honestly, back then I did not know really what an “urban area” looks like, and I thought this conglomerate of smaller towns, growing together to one urban cluster could have impacts on the atmospheric boundary layer that modify rainfall patterns. Actually, it does. But that’s a different topic. Earlier this week, …