Welcome back everyone.
Today I want to demonstrate how the focus on temperature anomalies severely misleads the public about the natural dynamics of climate change
Indeed, as illustrated here by NASA’s 2016 winter temperature anomalies, the data shows the rctic is warming 4 times faster than elsewhere and winters are warming faster than the other seasons.
However, a dubious narrative uncritically attributes rising CO2 to those anomalies, then speculates about a future warming crisis while ignoring important natural dynamics such as ocean currents.
But there is a wealth of scientific research that has shown ocean currents can also cause those higher temperature anomalies, but that isn’t obvious from this anomaly illustration. To add to the misunderstanding, the high Arctic temperatures are paradoxically due to heat ventilating out from the ocean and cooling the earth, thus actually preventing future extreme warming.
The warm 2016 winter temperatures in the eastern tropical Pacific were caused by a natural El Nino event that also ventilated heat previously stored in the western Pacific, briefly warming the air but again actually cooling the earth.
El Nino events also contribute to warmer sea surface temperatures simply by reducing the trade winds that drive upwelling of cold subsurface water. Such warming when upwelling is inhibited is observed globally. For example, a 3-month study showed how monthly changes in wind direction (the blue line) caused a 6 to 8C (14F surface temperature change.
Along the coast of Oregon, when winds blow in a southward direction, upwelling is enhanced, and surface temperatures fall (the red line).
Conversely, when winds blow to the north upwelling of cooler deeper water is inhibited causing temperatures to rise by 6-8C (14F).
Such dramatic natural temperature changes have nothing to do with radiative heating from the sun or greenhouse gases. Nonetheless warmer temperatures from reduced upwelling are often mistakenly incorporated into the global average temperature as seen during El Nino events and then attributed to CO2 warming.
It is far more insightful to understand climate change by looking at actual temperature changes. Using publicly available national weather service data, a quick survey of subarctic temperatures on January 29th, 2023, at 60 degrees latitude just south of the Arctic Circle, reveals how ocean currents alone cause tremendous temperature differences.
The Hudson Bay was -33C or minus 28F. Clearly any warming effects from greenhouse gases did not prevent such life threatening extreme cold. Such deadly cold temperatures evoke a much different concern for Hudson Bay inhabitants than NASA’s 2-degree warmer temperature anomaly, that laughingly is suggested as evidence of a global warming crisis.
Temperatures in the middle of the Labrador Sea jump 34 C or 60 F to a very livable temperature just below the freezing point.
Further east, higher Irminger Sea temperatures rise above freezing to 2.2 C or 36F.
And the Norwegian current is even warmer at 42F.
Benefitting from eastward winds that transfer ventilating heat from the warm Norwegian Current, the Norwegian coast reaches a balmy 7C or 44F in the dead of winter. Even though all measurements were taken at the same latitude, on the same date and same time, there is a huge 40C or 73F temperature difference between the Hudson Bay and Norwegian coast
Indisputably, that variability is caused by heat transported northward by ocean currents and ventilated to the Arctic atmosphere. It is the ocean currents that are the Arctic's climate control knob, not atmospheric greenhouse warming, as witnessed by the extremely cold Hudson Bay.
Indeed, a map of the warm and cold currents entering those subarctic seas, predicts precisely where temperatures would be warmest
The Norwegian current carries the warmest waters that originated in the Gulf Stream and North Atlantic Current.
A portion of the warm north Atlantic current that veered westward while ventilating some heat plus mixing with the cold east Greenland current keeps the Irminger Sea just above freezing but cooler than the Norwegian sea
Further ventilation of Atlantic heat and mixing with colder water lowers the observed Labrador Sea temperatures to just below freezing
NASA and a few other climate researchers have uncritically attributed declining winter sea ice to rising CO2 simply based on a negative correlation. Furthermore, by presenting the ice decline trend as a representation of all the Arctic and not a regional phenomenon, the National Snow and Ice Data Center's sea ice trend is a very misleading abstraction.
Their global warming correlation does not hold for 80% of Arctic winter sea ice extent.
Inside the Arctic Circle most of the winter sea ice extent has not been reduced, suggesting warmer air, purported to be derived from rising greenhouse gases, has yet to cause any change.
Furthermore, south of the Arctic Circle there is scant reduction for Bering Sea ice,
Nor is there any change in Hudson Bay winter ice extent. Of course, this is expected with winter temperatures hovering around -33C (-28F)
NSIDC graph of winter sea ice is driven by losses confined only to regions where warm Atlantic water intrudes, around the Norwegian sea, and more deeply into the Arctic Circle and the Barents Sea.
According to NSIDC, heat transported into the Arctic ocean has increased by 30% since 1900, making the variability of warm ocean currents the best explanation for the 20th century's ebb and flow of Arctic sea ice.
The cause of variable heat transport into the Arctic requires examining a complex of natural factors driving the great Ocean Conveyor Belt and its Atlantic segment, known as the meridional overturning circulation
The Atlantic is unique, in that warm water from the southern hemisphere crosses the equator and eventually reaches the Arctic.
Furthermore, the heating of water in the south Atlantic is partly controlled by the ocean Conveyor Belt's inflows from the tropical waters of the Pacific and Indian ocean. I won't discuss the circulation complexities of this segment any further here, except to share that La Nina conditions have a large impact. For those who want to understand the drivers of heating in those tropical waters, I suggest people view my previous video/blog on ocean heating "The Science of Solar Ponds Challenges the Climate Crisis".
Focusing on the Atlantic, research has determined 45% of the water passing through the Florida Strait and into the gulf stream originated from the south Atlantic.
Changes in the strength and location of Atlantic pressure systems and resulting ocean circulation determines how much heat enters the Arctic Circle or is recirculated southwards.
Unfortunately, most illustrations of the Ocean Conveyor Belt typically stop half-way up the Norwegian coast, but that is very misleading.
Warm Atlantic water circulates throughout the Arctic ocean and correctly predicts where Arctic temperatures will be the warmest.
The warmest temperatures are where Atlantic water first enters the Norwegian and Barents Sea, with ventilating ocean heat warming the air. Then slightly cooler Atlantic water continues to circulate through the 3 major Arctic basins beneath the thick sea ice.
A smaller volume of less warm water from the Pacific enters via the Bering strait
Whereas hardly any heat from intruding warm currents reaches the islands of the Canadian archipelago explaining the region's extreme cold.
Additionally, because the warm Atlantic water resides between 100- and 900-meter depths of the Arctic Ocean with a residence time of 25 to 30 years, any cyclical slowdown of the Gulf Stream may not be detected in Arctic Ocean temperatures or its sea ice extent for 2 to 3 decades
Again, we can observe how the pattern of intruding warm currents drives Arctic ocean temperature differences just inside the Arctic Circle at 70 degrees latitude.
Around Wrangel island where cool Pacific water enters via the Bering strait the temperature was -16.7 C or 1.9F.
However, where very little warm currents reach the islands of the Canadian archipelago, temperatures plummeted to -39C or -39F
For contrast, North Pole temperatures are 8C or 15F warmer than the archipelago due to Atlantic heat stored in the Arctic basins and ventilating through the ice. Partly due to such heating contrasts, Inuits hunting in the winter preferred to build their igloos on the ice instead of on land.
Temperatures over the southward out-flowing east Greenland current are -19C or -3 F in contrast to the temperatures of the adjacent inflowing Norwegian current that is 21C or 38F warmer.
Natural dynamics affect the flow of heat in the Atlantic segment of the Ocean Conveyor Belt. One dynamic is the location of the Intertropical Convergence Zone (or ITCZ) which caused a dramatic temperature effect at the end of the last ice age.
Ice core data show temperatures that had been rapidly warming suddenly dropped by 20C or 36F in the northern hemisphere for about a thousand years during a cold period called the Younger Dryas (YD). In contrast, southern hemisphere temperatures slightly warmed.
Proxy data suggests the westward trade winds and ITCZ had shifted southward causing the warm South Equatorial Current (SEC) to also shift southward. Brazil's eastern most land, Ponta do Seixas amplified that shift by deflecting more warm water back into the south Atlantic and thus cooling the north Atlantic.
The warmer 10,000 years of the Holocene period correlates with the ITCZ shifting northward, causing the warm South Equatorial Current to deliver more warm water across the equator, to warm the north Atlantic while cooling the south.
A similar but smaller southward shift of the ITCZ corresponds with the Little Ice Age which mostly cooled the northern Atlantic regions. The Little Ice Age ended around 1850 as the ITCZ moved northward for our most recent 150 years.
Like the drivers that caused and ended the Younger Dryas, the Atlantic Multidecadal Variability or Multidecadal Oscillation, represents 20+ years of warmer temperatures in the north Atlantic than the south and then reversing. This oscillation is intimately linked to variability of the surface currents in the Atlantic’s surface Meridional Overturning circulation within the Ocean Conveyor Belt.
First detected in the 1980s and officially named around 2000, the positive phase represents a warmer north Atlantic that is linked to several climate dynamics. From the 1930s to 60s and then 1990s to present, the positive warm phases were associated with less Arctic sea ice, increased Sahel rainfall, increased hurricane activity, and frequent heat extremes in the southwestern USA.
The negative phase from the 1960s to 1990 (represented in blue), saw a reversal of those dynamics as Arctic sea ice rebounded from its 1930s low extent. Accordingly, a 40-year research project over the Arctic ocean during a cool phase and published in 1993 determined there was an "absence of evidence for greenhouse warming" over the Arctic ocean.
So, for your sake, please understand these natural oscillations. Knowledge protects you from fear mongering politicians who blame loss of Arctic sea ice on the car you drive or that you like cooking with a gas stove.
There 3 guidelines to consider preventing being victimized by their climate misinformation.
First consider all the science, an abundance of researchers reports warming dynamics other than CO2. Science is a process, and nothing is settled yet.
Second become well acquainted with natural climate change. Natural climate change serves as the baseline, or the control data, from which to accurately judge the effects of CO2 emissions. The purpose of my series of climate videos and blogs is to provide a better understanding of the science of natural climate change to the public.
And finally, embrace renowned scientist Thomas Huxley’s advice: "skepticism is the highest of duties and blind faith the one unpardonable sin".
Thanks for watching!
