PBS: It’s been a summer of extreme weather: monsoon flooding is wreaking havoc in Pakistan and a persistent heat wave is fueling wildfires and creating health hazards in Russia. The United States has also not been immune, as sweltering high temperatures have plagued the East Coast, and deadly floods have hit the Midwest. This time of year always brings some treacherous weather to the northern hemisphere, but the events in Eastern Europe and Asia are “quite exceptional,” said Kevin …