Berlin, Jul 4 (AFP) German Chancellor Angela Merkel’s scientist-husband will take leaders’ spouses at a G20 summit, including Melania Trump, to a climate research centre amid a bitter row over global warming. Joachim Sauer, who usually shuns publicity, will take the visiting dignitaries sightseeing through Hamburg on a river cruise and to the spectacular new Elbphilharmonie concert house. But the quantum chemist has also insisted they stop off at the German Climate Computing Centre — an itinerary point sure to put the spotlight on the US First Lady after President Donald Trump in June pulled out of the 2015 Paris...