January was the most unusually warm month on record to occur in the absence of an El Niño event in the tropical Pacific Ocean, in another demonstration of the influence of record amounts of greenhouse gases in the atmosphere from human activities.
According to all the global temperature tracking agencies, the planet set a record for the warmest January since record-keeping began in the late 19th century. But in data released Thursday, the National Oceanic and Atmospheric Administration also made clear that the temperature record is more significant than it might first seem, particularly considering the string of record-breaking months. (The last month that was below average worldwide, when compared to the 20th-century baseline, was February 1985.)
The global land and ocean surface temperature for January 2020, NOAA found, had a temperature departure from average of 2.05 degrees (1.14 Celsius) above the 20th-century average. “The only Januaries with a global land and ocean surface temperature departure from average above 1.0°C (1.8°F) occurred in 2016 and 2019,” NOAA found.
But the January 2016 record occurred during one of the strongest El Niño events on record. Such events involve higher than average sea surface temperatures in the tropical Pacific Ocean, which adds tremendous quantities of heat to the oceans and atmosphere and acts as a natural temperature boost to an already unusually hot globe.
“This was not just the warmest January on record. It was probably the warmest January since we’ve had cities, and maybe since we’ve had language. And here’s the kicker: we broke this record without the extra push of an El Niño,” said Deke Arndt, the head of climate monitoring at the National Centers for Environmental Information, on his Facebook page.
NOAA scientists looked back at every month in every year that also had what’s known as ENSO-neutral conditions, meaning there was no El Niño or La Niña present. They found that January 2020 was the most unusually warm of these months, which not coincidentally have all occurred since 2017: February and March of 2017 and December 2019.
“A warm phase ENSO, also known as El Niño, tends to have a warming influence on global temperatures, while the cold phase (La Niña) tends to have a cooling influence," NOAA found. As these events are occurring, the buildup of greenhouse gases from burning fossil fuels has been boosting global average surface temperatures, ensuring that each successive El Niño event stands a good chance of setting new milestones, for example.
January 2020 featured incredible warmth in the U.S., Europe and much of Asia, among other locations. Helsinki saw temperatures rise above freezing every day. So too did Oslo, Stockholm and Copenhagen, with all of these cities except Oslo seeing no accumulating snow for the month.