Earth’s average temperature on Wednesday remained at an unofficial record high set the day before, the latest grim milestone in a week that has seen a series of climate-change-driven extremes. The average global temperature was 17.18 Celsius( 62.9 degrees Fahrenheit), according to the University of Maine’sClimate Reanalyzer, a tool that uses satellite data and computer simulations to measure the world’s condition.... That matched a record set Tuesday, and came after a previous record of 17.01 C