Enlarge (credit: Marc Bruxelle) "Climate breakdown has begun," declared UN Secretary-General António Guterres. Guterres is not a climate expert himself, but in this case, he's basing his opinion on the data and analyses generated by the actual experts. If you thought this year was a bit of a weather suffer-fest, it probably wasn't your imagination, as the Northern Hemisphere has just experienced its hottest summer on record, driving the year to date into the second-hottest position. While the weather isn't climate, the climate sets limits on the sort of weather we should expect.