https://youtu.be/0L_6fyH8KfI Videographic showing how cities can respond to heat waves. Northern hemisphere summers will deliver dangerously longer heatwaves, droughts and bouts of rain even if humanity manages to cap global warming at two degrees Celsius, according to a new study published in the journal Nature Climate Change. VIDEOGRAPHICS Fred Garet, Emmanuelle Bailllon / AFP Videographics / AFP