The 2019 Arctic sea ice minimum extent was probably reached on Sept. 18 and was the second-lowest extent on record. (NASA/EPA-EFE/Shutterstock) There is no powerful El Niño lurking in the tropical Pacific Ocean to add extra heat to the oceans and atmosphere, but the relentlessly accumulating greenhouse gases in the atmosphere, plus natural climate variability, have helped to push 2019 toward record warmth anyway. Through September, which the National Oceanic and Atmospheric Administration reported Wednesday was the hottest such month on record globally, the year ranks as the second warmest since instrument records began in the late 19th century. The odds slightly favor that 2019 will end up being the second-warmest year, coming in behind 2016. However, it’s possible it will slip slightly in ranking to third or fourth warmest, according to NOAA projections. September 2019 global temperature departure from average compared to previous Septembers. (NOAA) Matching analyses by […]