According to the National Oceanic and Atmospheric Administration, global average surface temperatures for the first three months of 2018 have eased off of their record-breaking streaks seen in recent years, with January and March each being only the fifth warmest months for their respective months, and February coming in as the 11th hottest February in the 139-year record. While this trend looks good on the surface, NOAA points out that each of these months’ temperatures are still well above the 20th century average, meaning we’re still far from out of the global warming gutter.
Each of these three months marked the 42nd consecutive month of above-average temperatures for their respective months, and also the 397th, 398th, and 399th consecutive months of above average temperatures. As is characteristic for a changing climate, regional land surface temperatures saw extreme departures from the norm, both in terms of high and low temperatures: deep cold snaps were experienced by central Eurasia in January at the same time northern Siberia was seeing temperatures well over 5ºC above normal; February saw a deep freeze engulf North America’s northwestern portions, while record highs were being seen in the Middle East and western Alaska; and while the Beast from the East engulfed northern Europe and western Siberia in record-breaking winter weather, heat waves in the Middle East, India and China set new record highs, with Pakistan setting a continental high of 45.5ºC (81.9ºF).
Regarding the global average, the current plateau in global temperatures that we’re seeing is due in part to a mild La Niña effect occurring in the Pacific, contrasting the record-breaking, back-to-back 2014-2016 El Niño events that culminated with 2016 being the hottest year on record. One has to bear in mind that the La Niña effect only pertains to a cooling of the ocean’s surface along the equator across the Pacific Ocean, meaning most of the heat energy being stored in the water is currently making its way through the ocean depths, and will heat the surface back up when it resurfaces during the next El Niño cycle.
With the conclusion of the 2018 winter sea ice maximum in the Arctic, this season’s sea ice extent was also the second lowest on record, a mere 30,000 square kilometers (11,600 square miles) ahead of 2017’s record low. The Bering Sea alone lost roughly a third of its ice cover in just over a week in early February. Less surface ice brings about a combination of less solar radiation being reflected back into space and more fresh water being released into the ocean, heralding potential trouble for the Atlantic meridional overturning circulation (AMOC).
- A portion of a GOES-EAST composite satellite image in visible and infrared light, centered on the U.S. East Coast. Image credit: NASA-Goddard Space Flight Center, data from NOAA GOES
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