We’ve left the 20th century far behind. This is a big deal. — Deke Arndt, head of NOAA’s National Centers for Environmental Information
One of the top three strongest El Ninos on record is now little more than a memory. According to NOAA, sea surface temperatures (SSTs) in the Central Equatorial Pacific hit a range more typical to La Nina conditions last week. This cool-pool formation follows a June in which ocean surfaces in this zone had fallen into temperatures below the normal range.
(El Nino had faded away by June and turned toward La Nina-level temperatures by late June and early July. Despite this Equatorial Pacific cooling, June of 2016 was still the hottest June on record. Image source: NOAA.)
But despite this natural-variability related cooling of the Equatorial Pacific into below-normal ranges, the globe as a whole continued to warm relative to previous June temperatures. According to NASA, last month was the hottest June in the global climate record.
NASA figures show the month was 0.79 degrees Celsius warmer than the 20th century baseline (1951 to 1980) average, edging out June of 2015 (when El Nino was still ramping up) by just 0.01 degree C to take the dubious position of the new hottest June ever recorded by human instruments. June 2016 was also about 1.01 C hotter than temperatures in the 1880s, at the start of NASA’s global climate record.
January to June — Anomalous Warmth Centers Over Arctic
June marks the 9th consecutive hottest month on record in the NASA data. In other words, on a month-to-month comparison, each month since October of 2015 was the new hottest of those months ever recorded. In addition, the six-month 2016 climate year period of January to June showed an average global temperature of about 1.31 C above 1880s averages — perilously close to the 1.5 degree C global climate threshold.
(Arctic heat dominated the first half of 2016 which is likely to end up being the hottest year ever recorded in the global climate record. Image source: Berkeley Earth.)
Distribution of this anomalous heat during this six-month period, despite the Equatorial warming pulse related to El Nino, was focused on the Arctic, as we can see in this Berkeley Earth graphical composite of the NASA temperature series above.
Warmest temperature anomalies for the period appear above the Barents and Greenland Seas boundaries with the Arctic Ocean and approach 12 C for the six-month period. During this period, this region has hosted numerous warm-wind invasions of the Arctic from the south. A second, similar slot of warm south-to-north air progression appears over Alaska.
Record June Warmth Most Apparent at Northern Continental Margins
During June, the Arctic as a whole remained much warmer than average, with the region from latitudes 80° to 90° North seeing a +0.8 C temperature departure in the NASA measure. The highest anomaly regions globally, however, were near the continental margins bordering the Arctic Ocean in the region of latitudes 70° to 75° North. Here temperatures ranged near 2 C above average.
(According to NASA’s zonal anomaly measure, the northern continental margins showed the highest temperature anomalies globally. Image source: NASA GISS.)
Some parts of this region were particularly hot. These included the region of Russian Siberia near the Yamal Peninsula, which saw 4-8 C above average temperatures for the month, the Bering Sea and Northeastern Siberian region adjacent which saw 2-8 C above average temperatures, and the Canadian Archipelago which saw 2-4 C above average temperatures for the month.
Odd Warm-Air Slot Runs from Equator to West Antarctic Peninsula
Notable is that visible warm-air slots running from Tropics to Pole appear to remain intact in the Northeastern Pacific and over Central Asia in the Northern Hemisphere during early Summer. Meanwhile, an odd Southern Hemisphere warm-air slot appears to have developed during June in the region of the Southeastern Pacific.
(June of 2016 was the hottest June on record. This is what the anomaly map looked like. Image source: NASA GISS.)
This particular Equator-to-Pole heat transfer appears to have run as far south as the West Antarctic Peninsula and assisted in producing a 4-8 C above-average temperature spike there.
As the majority of the world remained hotter than normal during June of 2016, the only noted outlier cool region was Central and Eastern Antarctica which, in spots, saw 4 to 7.1 C below-average temperatures.
2016 is Blowing All Previous Years Away
Overall, as El Nino continues to shift toward neutral or La Nina states, global temperatures should remain lower than during peak periods seen earlier this year. It’s likely that over the coming six months, the very long period of new monthly global record temperatures we’ve seen will eventually be broken by a top-five- or top-10-hottest month.
(2016 is on track to blow all previous record hot years out of the water. See related article here.)
However, it appears that global heat has in total taken a big step up. As such, 2016 appears to be set to average near 1.14 to 1.25 C above 1880s levels. That would beat out previous hottest year 2015 by a big margin. To this point, Deke Arndt, head of NOAA’s National Centers for Environmental Information, recently noted in The Scientific American:
“It’s important to keep perspective here. Even if we aren’t setting [monthly] records, we are in a neighborhood beyond anything we had seen before early 2015. We’ve left the 20th century far behind. This is a big deal.”
In other words, that’s about a decade’s worth of typical human-forced warming in just one year. If it shapes up that way, it basically blows all previous years out of the water. Pretty nasty to say the least.
Hat tip to Zack Labe
Hat tip to DT Lange