“What is happening right now is we are catapulting ourselves out of the Holocene, which is the geological epoch that human civilisation has been able to develop in, because of the relatively stable climate. It allowed us to invent agriculture, rather than living as nomads. It allowed a big population growth, it allowed the foundation of cities, all of which required a stable climate.” — Stefan Rahmstorf
A strong El Nino in 2015 helped to contribute to record hot global temperatures over the past three years. But with so much heat unexpectedly showing up in the global climate system, there’s clearly something else going on. And indicators are that the natural climate variability that human beings have grown accustomed to over the last 10,000 years may now be a thing of the past — as it is steadily overwhelmed by a stronger overall greenhouse gas based warming signature. One that is concentrating more and more warming near the poles.
Natural climate variability steadily overwhelmed by stonger overall greenhouse gas based warming
2014 was the hottest year on record. But that lasted only until the end of 2015 — which shattered the 2014 global heat record by a big margin. Then 2016 rolled around and produced what could best be described as an insane heat spike during the January through May period. Now, it’s about 95 percent certain that the 2015 record will also fall, leaving 2016 as the new hottest year on record in yet one more climate vertigo inducing temperature jump.
The rate of warming for 2014 through 2015 is just off the charts. This scares scientists, and it should. This makes many climate experts wonder about causes, and it should. Prime suspect for the increased rate of change — amplifying feedbacks in the Arctic.
Prime suspect for increased rate of change = amplifying feedbacks in Arctic
In the end, temperatures are expected to level off near 1 C above 20th Century averages and around 1.2 C above 1880s averages by the end of this year. That’s a 0.3 C leap up since the mid 2000s. A screaming rate of decadal warming that is about twice as fast as that experienced since 1979. That’s an insanely fast pace of heat build-up. And it’s got many scientists seriously concerned.
Records not just broken, but obliterated –
16 of the 17 warmest years on record since 2000
The records, as the Guardian aptly notes, were not just broken, they were obliterated.
Adam Scaife, a scientist at the Met Office in the UK, agrees:
“The numbers are completely unprecedented. They really stick out like a sore thumb… Including this year so far, 16 of the 17 warmest years on record have been since 2000 – it’s a shocking statistic.”
So what the heck is going on? We know that a strong El Nino just passed. But, though a real beast of a thing, the 2015-2016 event wasn’t quite as powerful as the 1997-1998 El Nino. And global temperatures will end up being about 50 percent hotter than 1998 averages by the end of this year. Essentially leaving this great El Nino’s heat spike in the dust. Meanwhile, scientists attribute about 1/5th of the 2014 to 2016 heat spike to El Nino. The rest came from someplace else. But where?
Only a fifth of heat attributed to Al Nino
The first obvious suspect is greenhouse gasses. In 1998, atmospheric CO2 levels peaked at around 365 parts per million at the Mauna Loa Observatory. This year, that heat trapping gas hit near 408 parts per million in the same measure. That’s a 43 parts per million jump peak to peak in just 18 years. A 12 percent increase in a gas that is capable of causing severe geo-physical changes in what, geologically speaking, is not even a blink of an eye. And you have to go back millions of years into Earth’s history to find times when CO2 readings were so high.
So the big build-up of heat trapping gasses is the obvious driver of the overall insane rate of warming that we are now seeing. But that doesn’t account for what is an unexpected acceleration over the past three years. And to puzzle out that speed-up we need to dig a little deeper. To consider factors that are known as amplifying feedbacks.
And, thankfully, in this investigation, we are not flying completely blind. NASA and the other global climate monitors give us a rough global overview of where the Earth is warming up the fastest. And an investigation of comparable temperature anomalies at the Earth’s surface can give us some indication where the extra heat is coming from and why.
1997 — Some Polar Amplification (aka Death of Winter)
The obvious choice is to pick two relevant years for comparison. And for our purposes we’ll pick 2015 and 1997. The reason for this pick is that both 1997 and 2015 were years in which strong El Ninos were building up and having their impact on the global climate system. And based on what we know about El Nino, we can expect a lot of heat coming out of the Equatorial Pacific as sea surface temperatures there ramp up. In a climate system that is only driven by a natural variability related El Nino, what you’d expect is that the primary heat spike would be in the Eastern Equatorial Pacific region. Any other heat spike would be a possible indicator of another climate driver for global temperatures.
So for the year of 1997 (Jan-Dec) we find that a strong heat pulse does originate from the Eastern Equatorial Pacific region. In fact, it’s the largest zone containing temperature anomalies in the range of 2 to 4 C above average. But during this year we also find some pretty big anomalies in Central and North Asia. These flow across the Bering Sea into Alaska, Northwest Canada, and the Beaufort. High Arctic temperatures are somewhat cooler, though still anomalously warm. And West Antartica also shows its own, not insignificant temperature spike.
Given the fact that El Nino will tend to strengthen the Jet Stream and generate a warming bias in the tropical zones, we can already see that there’s probably some polar amplification going on in 1997. And overall, the northern polar zone from 66 North to 90 North shows a positive anomaly signature that is just 0.1 C shy of the equatorial anomaly produced by El Nino. But the heat signal between El Nino and Northern Hemisphere polar amplification appears to be more balanced, with El Nino still providing a slightly stronger share of the overall heat contribution.
Understanding Polar Amplification’s Impact Due to Global Warming
For reference — polar amplification is an expected more rapid increase in polar temperatures as global greenhouse gas concentrations increase. Under pressure from greenhouse gasses, the poles warm faster for a number of reasons. The first is due to albedo or reflectivity loss as ice melts. White ice changing to brown earth or blue ocean due to melt absorbs more sunlight and creates a preferential warming at the poles. In addition, greenhouse gasses (especially CO2) capture and re-radiate sunlight’s heat energy like a blanket. As a result, temperatures tend to homogenize more over the globe resulting in a greater rate of temperature increase where it’s coolest and darkest. And the poles are the coolest and darkest places on Earth.
A third cause of polar amplification involves added heat resulting in natural carbon store release. And some of the greatest concentrations of the world’s sequestered carbon stores are locked in frozen ground and water at or near the poles. If ice at the poles thaws, you tend to end up with a higher overburden of greenhouse gasses in these regions. This is particularly true in the Northern Hemisphere where large regions of permafrost and ocean carbon stores are more vulnerable to release from early warming than the deeply sequestered stores in Antarctica.
Dr. Jennifer Francis’s observations on Jet Stream weakening and polar amplification have big implications both down [Pole] and up [Equator] stream:
Finally, as the polar zones warm up, they tend to generate weaknesses in the circumpolar Jet Stream. This is due to the fact that temperature differences between pole and tropics drive both Jet Stream speed and strength. As the relative difference drops off, the Jet Stream slows. And when the Jet Stream slows it meanders — creating big troughs and ridges centering on the middle Latitudes but sometimes extending all the way up to the poles. In the ridge zones, warm air is able to drive further north or south. And this feeds polar amplification by linking hot Equatorial air masses with the Pole itself. Over recent years, high amplitude Jet Stream waves have become a regular feature of the global climate system and have been associated with numerous extreme weather events — some of the most notable being the Russian Heatwave and Pakistan floods of 2011 and the anomalous late December 2015 warming of the North Pole above freezing.
2015 — Polar Amplification in the Driver’s Seat
By 2015, the polar amplification signature, especially in the Northern Hemisphere, started to look ridiculously strong.
And during this year we find that the zone of greatest temperature anomalies lies not over the Equatorial Pacific — but over the high Latitude regions of the Northern Hemisphere. 2-4 C above average temperatures dominate a huge zone stretching from North Central Asia and Europe and on up to the North Pole. A similar zone dominates Northwestern Canada, Alaska and the Beaufort Sea. And pretty much the entire Northern Hemisphere Polar and near Polar zone falls under 1-4 C above average temperatures for the year.
By comparison, the Eastern Equatorial Pacific appears to play second fiddle to the Polar and near Polar heat build up. A broad region across the Central and Eastern Equatorial Pacific does see 1-2 C above average temperatures, with a small pool of 2-4 C deltas off South America. But it’s not that much greater a signal than a significant heat pool over the Indian Ocean. And the Northern Hemisphere near Polar zone is altogether the area that’s clearly the global heat center of gravity. An observation bearing out in NASA’s zonal anomaly measure which finds that Latitudes 66 to 90 North were about 1.6 C above average and the highest relative temperature anomaly zone on the planet. Meanwhile, the Equator lags at +1.2 C above normal. That’s a relative Equator to Pole anomaly change of +0.5 C from El Nino years 1997 to 2015. An indicator that El Nino may no longer be the primary driver of the global temperature and climate engine. And that its overall role is greatly diminished over the 1997 to 2015 timeframe. And, finally, that a greenhouse gas based warming polar amplification signature is now in the driver’s seat.
So, basically what we have during an El Nino year is the pole warming relative to the Equator and under any condition other than human forced climate change — this is something that definitely should not happen. In other words, you’re not in Kansas anymore and Kansas isn’t on Earth anymore. At least the Earth that human civilization is used to. For what we’re experiencing is the climate of a planet that is definitely not operating under Holocene norms — but under the transitionally destabilizing forces of greenhouse gas based warming.
Warm Air Slots and The Death of Winter
So in comparison to 1997, it appears that during 2015 the Northern Pole gained heat very rapidly (increasing by +1 C over these 18 years) while Equatorial heat continued to build (adding +0.4 C over the same period). In other words, Polar warming was about 2.5 times faster than Equatorial warming during the 18 year interval. The result is that by the El Nino year of 2015, the Pole showed dramatically higher relative global temperature anomaly spikes. This, in a few simple words, is the evidence of a greenhouse gas warming based polar amplification writ large. But digging down into the details a bit more we find a number of further disturbing clues as to what’s really going on in the grinding gears of our global climate machinery.
September of 2015’s crushed polar vortex and high amplitude Jet Stream wave patterns during a peak period of Equatorial heat known as El Nino is a bad, bad sign. A clear indication that polar amplification is starting the drive and destabilize the global climate regime.
The first is the appearance of a big warm air slot running directly from the Equatorial Pacific over the Eastern Pacific and North America and on up into the Northern Polar zone. Here we find the signature of 2015’s ridiculously resilient ridge (RRR) pattern in the NASA global anomaly map for the year. Warm air consistently funneled directly from the Equator, was drawn through the high amplitude ridge (see Dr Francis’s video above) and pulled into the polar zone.
But the RRR zone wasn’t the only big warm air slot pulling air north during 2015 — just, perhaps, the most obvious. A second big warm air slot appeared over the Eastern North Atlantic, Western Europe and extended to cover most of Asia. And this enormous Equatorial air sucking beast really ramped into high gear during late December of 2015 when it drove North Pole temperatures above freezing.
Taken in total, these warm air slots were enormous — exerting an amazing influence over the totality of global weather. The overall story is one in which the polar vortex was basically getting smashed during an El Nino year. Another big indication that things are teetering pretty far off kilter. One indicator of this was an anomalous spiking of all the upper level Equatorial wind speeds at the same time (in the Quasi Biennial Oscillation measure) during September of 2015. An event that current climate theory says shouldn’t happen, but it did. And yet one more hint that the Hadley Cell produced a huge northward bulge at the time. It’s also an indicator that Northern Hemisphere Winter is getting steadily beaten back to the ropes by the bully of northward running heat.
So what we’ve seen from 1997 to 2015 is a dramatic transition in which El Nino appears to have lost climate influence powers and become a slave to what is now a heat-sucking engine at the pole. It’s an emerging first phase of a death of winter type scenario. And the upshot is that the extra heat in the system that scientists are getting pretty concerned about appears now to be coming in large part from a ramping Northern Hemisphere polar amplification.