During his short visit to the  UN COP30 summit  in Brazil last week, German chancellor Friedrich Merz was keen to present himself as serious about climate protection.  "We are at a crossroads,"  Merz told world leaders in the Amazon city of Belem, emphasizing all countries must act now on climate change in the interest of their security and long-term prosperity. But since his election to in May, Merz has far from played the role of a climate leader —  and his visit to Brazil did little to