By the narrowest of margins, last month was the hottest September in recorded history, NASA data has revealed, meaning that 11 of the last 12 months have seen record-breaking heat and all but assuring that 2016 will go down in the books as the warmest year since at least 1880.
According to a monthly analysis of global temperatures by scientists with the US space agency’s Goddard Institute for Space Studies (GISS) in New York, September 2016 edged out September 2014 by just 0.004 degrees Celsius, placing the two months in a statistical tie. However, the past four week period was 0.91 degrees Celsius warmer than the mean from 1951-1980.
Since October 2015, 11 of the past 12 months have shattered monthly high-temperature records, with the lone exception being June 2016, according to GISS. While previous reports had claimed that June 2016 was the warmest such month in the 136-year history of modern record keeping, it was actually just the third hottest behind 2015 and 1998, based on updated climate data.
“Monthly rankings are sensitive to updates in the record, and our latest update to mid-winter readings from the South Pole has changed the ranking for June,” GISS director Gavin Schmidt explained in a statement. “We continue to stress that while monthly rankings are newsworthy, they are not nearly as important as long-term trends.”
Disagreement in monthly data, but annual record still likely to fall
However, as reported by the Huffington Post, Schmidt also tweeted that the data for September suggests that 2016 will almost certainly be the hottest ever recorded, as it has been approximately 1.25 degrees Celsius above the late 19th century mean through the year’s first nine months.
Should that happen – and barring a much-colder-than-average fourth quarter of the year, it will – it will be the third consecutive year that the record for hottest annual temperature was shattered, according to CNN.com reports. Average temperatures for 2015 were 0.90 degrees Celsius higher than the 20th-century average and 20% higher than the benchmark set the previous year.
Provided 2016 set the record, it would mean that 16 of the 17 hottest years ever recorded would have come since 2000, with 1998 being the lone exception. The last time that the planet shattered the record for the coldest year on record was 1911, the website noted. A thirdconsecutive record year would “confirm the longer term trends of climate change,” The Guardian said.
However, not all climate-recording agencies are in agreement. In fact, the US National Oceanic and Atmospheric Administration (NOAA) is reporting that September 2016 was not the hottest month of its kind in recorded history. They claim that it was actually 0.04 degrees Celsius cooler than the previous September, which snapped a string of 16 straight record-setting months based on their data. Nonetheless, they say that 2016 is likely to be the hottest year ever.
“If each month from October through December matches the 1998 monthly values… 2016 would become the second warmest year on record, behind 2015 by 0.03°C (0.05°F),” NOAA wrote. But if those months matched “the 21st century monthly average,” they explained, “[then] 2016 would become the warmest year on record, surpassing 2015 by 0.01°C (0.02°F).”
Image credit: NASA/NOAA