In climate news, the World Meteorological Organization said Thursday that July was the warmest month in recorded human history. It followed the hottest June on record, as atmospheric carbon dioxide levels climbed to a record high of 415 parts per million earlier this year. Scorching heat waves have put 2019 on track to be one of the hottest years ever measured. The current record holders are, by rank, 2016, 2015, 2017 and 2018.