Last month was the hottest September ever recorded, paving the way for 2016 to be the hottest year since record-keeping began, NASA scientists said this week.
This September beat the same month in 2014 by a tiny margin of 0.004°C (0.007°F), according to NASA. The temperature is 0.91°C (1.64°F) warmer than the average September temperature in the four decades beginning in the 1950s. The National Oceanic and Atmospheric Administration (NOAA), which tracks temperatures slightly differently, found that this September was the second hottest September on record, by a very small margin.
"Monthly rankings are newsworthy," says Gavin Schmidt, a NASA climatologist. But "they are not nearly as important as long-term trends.”
The long-term trends have scientists concerned. Last year beat 2014 as the hottest year on record, and scientists are now all but certain 2016 will be even hotter thanks both to global warming and a particularly strong occurrence of El Niño, which raised temperatures across many parts of the globe. Eleven of the past 12 months have been the warmest on record, according to NASA data.
The string of temperature records brings global warming close to the 2°C (3.6°F) level of warming that scientists warn could lead to the worst effects of climate change. In February, the global temperatures were 1.2°C (2.2°F) higher than average, according to NOAA.