Heat waves are 100% Natural

 

Watch the video 

HEAT WAVES ARE 100% NATURAL- PART 5: HOW PRESSURE SYSTEMS CONTROL CLIMATE

at https://youtu.be/eddO6RVZ2CM

Below is the video's transcript :

Welcome everyone

Heat waves provide the perfect optics for those who want to push climate alarmism arguing CO2 is causing the world to dramatically overheat. 

Using uncontested physics and published peer reviewed evidence I will conclusively show heat waves are all natural. So today in part 5 of how pressure systems control climate, I examine how natural shifts in the location and duration of high-pressure systems cause heatwaves.

Various researchers will define heatwaves differently depending on the hypotheses they want to support.

But the American meteorological organization defines a heat wave as a weather event during which maximum temperatures are 5+ degrees Celsius higher than average on those dates and lasts for 5+ consecutive days

Researchers that push a CO2 driven climate crisis, argue that it is the shift in the average global temperature that results in more extreme heat waves and more record high temperatures.

But that is misinformation. Any honest and critical thinker will readily see the peak in USA heatwaves, as illustrated by the EPA, happened in the 1930s and there is no correlation with the global warming trend.

Clearly heatwaves and extreme temperatures are caused by factors other than changes in the global average temperature statistic. Such a false manufactured statistical argument is why Mark Twain's quip that there are” lies, damn lies and statistics” has resonated for over a century.

To put heat waves and extreme temperatures into perspective we first see that the theoretical maximum ground surface temperature has been estimated to lie between 90 and 100 Celsius or 194 to 212 Fahrenheit.

The air temperatures used to generate a global average are primarily heated by contact with the earth's solar heated surfaces, air temperatures correlate with ground temperatures but are 30 to 50 degrees Celsius cooler.

Based on that difference we can infer the theoretical maximum air temperatures should lie between 50 and 60 Celsius or 122 and 140 Fahrenheit.

The science of heatwaves and maximum temperatures have determined 5 basic factors to evaluate any trends

• First, maximum temperatures are determined by the overhead angle of sunlight which is greatest in the tropics, clear skies permit maximum insolation but are greatest in the subtropics under high pressure systems.

• Second, because air is heated by contact with the ground, changes in surface conditions are very important. Dry surfaces heat to much higher temperatures than moist surfaces without any added solar or greenhouse heating

• Third temperatures in descending air currents also increase temperature without any added heat energy due to increasing pressure. As witnessed under high pressure systems and foehn winds.

• Fourth changes in mixing can also increase air temperatures without any added solar or greenhouse heating. For example, warm air transported from the Sahara Desert has raised temperatures during Europe’s heatwaves

• Finally, there is the balance between radiative heating and radiative cooling. Climate crisis narratives suggest increased CO2 slows the escape of infrared heat energy, reducing the rate of cooling and thus warming the earth. But counter-intuitively, outgoing infrared heat energy increases, Due to the dry conditions beneath high pressure systems, thus reducing any greenhouse effect.

The most intense solar heating happens in the tropics and least in the polar regions.

The direct rays of the sun are overhead and concentrated during the northern hemisphere's summer shifting as far north as 23.5 N degrees then traveling to 23.5 S degrees for the southern hemisphere's summer. This swath of latitudinal heating from the most intense sunlight defines the tropics, but due to cloudiness the earth's most extreme temperatures don't happen in the tropics.

North America’s and also the world's record for the hottest extreme temperature ever measured is 

56.6 Celsius or 134 Fahrenheit measured in Death Valley located in the sub-tropics at 36 degrees north on July 10, 1913. 

This century old record again refutes any correlation with global average warming trend. It is likely this record has not been broken because it lies close to the theoretical maximum caused by the combineD dynamics previously outlined.

Africa's record maximum is 55 degrees Celsius or 131 Fahrenheit on July 7, 1931, in Tunisia at 32 degrees north.

Asia's record maximum of 54 degrees Celsius or 129.2 Fahrenheit happened in Israel on June 21, 1942, at 32 degrees north. 

These extreme temperatures all happened within weeks of the summer solstice, during a colder global average temperature, and in the subtropics where dry desert conditions, and cloudless high-pressure systems prevail.

Europe's record maximum happened in Athens Greece on July 1977

Australia's record of 50.7 Celsius or 123.3 Fahrenheit happened in January 1960 in Oodnadatta Australia 

that claims to be the driest town in the driest state of the driest continent

Science clearly explains the contribution of dryness to extreme temperatures

Dry soil requires just 0.8  jouleS of energy to raise a gram of dry soil by one degree. In contrast wet soil requires more than twice that energy to raise a gram by one degree.

In addition, over 2200 joules are required to evaporate a gram water without raising its temperature causing evaporative cooling. Without adding any heat energy from the sun or greenhouse gases, increasing dryness raises local temperatures. 

Again, illustrating why temperature change is not a reliable indicator of increased greenhouse warming.

The much higher temperatures measured in big cities is called the urban heat island effect, which amplifies the public's suffering during a heat wave. The urban heat island effect is caused in part by the drying of the landscape as rains are quickly diverted into storm sewers instead of moistening the ground. In addition, the landscape is increasingly covered in asphalt and concrete which takes less energy to heat and holds that heat longer.

Those who push a climate crisis often use this graph of warming temperatures in the USA’s 50 large cities from climate.gov But to claim that warming trend is due to rising co2 is misinformation that ignores the increasing drying effects

Foehn winds are another example of higher temperatures that are not caused by added solar or greenhouse warming, but warm adiabatically solely due to increasing air pressure.

Moist air approaching a mountain are forced upwards on the windward side. The release of latent heat from condensing water vapor helps the air rise. On the leeward side as the air descends it warms to several degrees warmer than on the windward side solely due to increasing pressure.

The record temperature of 18.3 Celsius or 64.9 Fahrenheit for Antarctic happened on February 6, 2020, 

much to the delight of the co2 climate crisis crowd. But this record was caused by a foehn wind descending on the Esperanza base which is located at the tip of the Antarctica peninsula, the continent's most equator-ward location.

Depending on the strength and attack angle of the westerly winds, the winds will travel around the peninsula or at other times go up and over the peninsula's mountains. The Antarctic record temperature was simply an example natural adiabatic heating.

High pressure systems are created by dry descending air currents that also heat the air adiabatically the same as foehn winds

High pressure systems are almost always associated with a heat wave. The dry descending air creates clear skies that allow more solar heating. In addition, the adiabatically warmed descending air prevents warm surface air from rising and mixing with cooler air creating a heat dome, analogous to the heating of a car with its windows rolled up.

With the age of satellites, we can now measure changes in outgoing long-wave radiation (OLR) while surface weather stations measure incoming solar radiation at the surface.

As illustrated here, during a heatwave in China, the yellow to red colors represent increased downward solar radiation and increased outgoing long-wave radiation measured in watts per meter squared. One watt is equal to one joule of energy per second. Compared to about just 2 W/m2 of CO2 downward heat, the center of this heat wave here, exhibited an increase of 30 to 40 outgoing watts/m2, suggesting a decreased greenhouse effect during a heat wave due to drier air.

In fact, scientists using satellite data, look for such increases in outgoing infrared to determine the location, intensity, and extent of heatwaves around the world.

The heating around the equator causes rising air that draws in moisture on the trade winds that converge and rise forming the intertropical convergence zone.

Prevented from rising higher at the tropopause, the winds are now re-directed towards the poles. Those high-altitude winds converge with equator-ward winds forcing air down to the ground.

This creates a quasi-permanent band of high-pressure systems around the globe centered at about 30 degrees.

Upon reaching the ground descending air is now redirected. Some moving back towards the equator and due to the Coriolis effect form the trade winds and complete the circulation cell known as the Hadley cell. See part 2 of this series for a discussion on how the Hadley cell creates the world's rainforests and deserts.

Other wind currents are directed northward and due to the Coriolis effect form the westerly winds. 

Where these winds converge with winds from the north pole the air is forced upwards forming regions of low pressure. This dynamic of converging winds forming high- and low-pressure systems can be thought of as a short-wave train

Furthermore, these regions form the major jet streams that modify the location of these pressure systems

In 2003, 2010 & 2018 Europe experienced heat waves that broke many local temperature records. All were triggered by drought and high-pressure systems

According to a peer reviewed paper analyzing the contributing factors Black (2006) also found a regionally intensified ITCZ for the 2003 heatwave. 

Here the northward ITCZ is represented in green as reduced outgoing heat waves, which shifted high-pressure systems further north, illustrated here in red, representing increased outgoing heat waves

In addition, both Black and Sparnocchia (2006) reported "hot dry air was pumped into western Europe from the Sahara"

El Ninos and La Ninas can shift the location of intense convection of the ITCZ. During a La Nina, intense convection is located over the western pacific warm pool which induces a wave train of sinking air and high pressure over Africa and also over the eastern Pacific, which then induces low-pressure and rain over the Atlantic as seen here.

(I also suggest seeing part 4 discussing how La Nina’s increase the strength of the warm pool causing global warming.)

Intense La Nina convection further triggers a wave train of high- and low-pressure systems that stretches across the Atlantic into Europe and Asia

A map of anomalously wet and dry weather across the globe during a La Nina demonstrates its dominant global teleconnections. It was a La Nina wave train that brought dry weather over the USA’s Great Plains and, with that dryness further amplified by landscape degradation, generated the Dust Bowl and the USA’s period of greatest heat waves.

During an El Nino, the warm water and center of intense convection moves eastward. Sometimes it reaches all the way to the coast of the Americas, and sometimes only to the central Pacific. This induces varying wave trains with a high pressure over Indonesia causing reduced Asian monsoons and drought. 

The 1997-98 El Nino brought floods to California and simultaneously extreme drought and a deadly heat wave to Indonesia.

Scientists also determined, since the 1960s El Nino events have amplified heat waves across China

El Nino wave trains also trigger anomalously wet and dry regions around the world but in different regions than La Nina and neutral years.

As Chase (2006) and other scientists have come to realize “natural variability in the form of El Nino & volcanic eruptions is of much greater importance for causing extreme regional temperature anomalies, than a simple upward [warming] trend in time" 

The Madden-Julian Oscillation begins with intense convection over the western Indian ocean warm pool that induces descending air and a high pressure further to the east. Then over the course of 60 to 90 days the low- and high-pressure systems move in tandem across the pacific until it reaches the cooler waters upwelled in the eastern pacific

The Madden-Julian Oscillation likewise creates wave trains such as this one causing high-pressure and a heat wave over the coast of South America.  The interaction of all these varying wave trains makes for complex weather patterns

Poleward wave trains from El Ninos, La Ninas and the Madden Julian Oscillation will affect the Arctic Oscillation during which the polar jet stream shifts from strong west to east zonal flow in its positive phase, switching to a more wavy flow in its negative phase which disrupts the eastward flow with more northward and southward flows.

Complex interactions with multiple wave trains affects the Arctic Oscillation causing its phases to switch from month to month. Such monthly phase changes are evidence of natural variability that refutes theories arguing the wavy jet stream is driven by less arctic ice and a climate change warming trend. 

During February 2021's valentines week, a wavy flow brought cold arctic air southward & deep into the heart of Texas, causing a deep freeze and major societal disruptions.

Just months earlier in June 2020 a very strong zonal flow of the positive phase prevented cold arctic air from moving south, which would normally moderate the summer temperatures around the Arctic Circle.   

Accordingly, on June 20th, 2020, Verkhoyansk Russia, just north of the Arctic Circle, reached its all-time maximum temperature record of 38 Celsius, or 100.4 Fahrenheit, to also become the hottest recorded temperature inside the arctic circle

Overland (2020) rightfully concluded this Siberian heat wave and extreme temperature was an example of random weather. But despite contradictory evidence, Overland also dutifully suggested climate change and Arctic Amplification had made the heat wave worse.

Overland ignored that for 30 years prior to this extreme weather event, Verkhoyansk's June temperatures demonstrated a cooling trend.     

Furthermore, the previous record high temperature deeper inside the Arctic Circle was just 0.2 degrees Celsius cooler, measuring 37.8 Celsius. or just 0.4 degrees Fahrenheit cooler at 100 F and set in 1915 at Fort Yukon, Alaska.

Just a 0.2 degree increase over one hundred years is, in reality, evidence of an extremely small long-term warming trend due to any Arctic Amplification. And given how sparsely populated it is inside the arctic circle, it is highly likely many other Arctic regions have also experienced similar warm temperatures due to the Arctic Oscillation's jet stream barrier preventing southward flows of cold air; temperatures that were simply not recorded. Nonetheless the UN News, in support of its IPCC’s climate crisis narrative, characterized this weather event as a "disturbing high temperature record". So be scared people!

The North Atlantic Oscillation is the regional expression of the Arctic Oscillation and similarly bounces between a wavy jet stream in its negative phase and a strong west to east zonal wind in its positive phase, and varying from month to month. And again, it is a measure of natural weather variability independent of climate change but causing climate related changes.

As published by Mysak (1990), interactions between El Ninos and the jet stream increased waviness that caused sea ice to expand in Baffin Bay to the west of Greenland where the jet's southward flow brought colder air. Simultaneously it caused sea ice reduction to the east of Greenland caused by the wavy jet's northward flow of warmer air. 

Wavy jet streams also slow down the west to east migration of storms and the high-pressure systems that are typically observed in daily weather patterns. That enables blocking high pressure systems to sit over a given region for weeks causing long-term heat waves. A blocking high-pressure system enabled the lengthy 2010 Russian heat wave, and a blocking high pressure system enabled the 2019 European heat wave.

Looking at northern hemisphere temperature anomalies during the Russian 2010 heat wave, we see a quasi-stationary wave train with a hot, dry high-pressure system centered over western Russia causing a month and a half of extremely hot temperatures, a colder low pressure sits over central Russia and a warm high pressure over eastern Russia and cooler temperatures in the north pacific

Randall dole is an expert on blocking high pressure systems and concluded the 2010 Russian heat wave was "mainly due to natural internal atmospheric variability" that causes blocking high pressure systems and heat waves seen in red, to form every few years in the region while dry land surfaces amplified the 2010 heat

Hauser (2016) reported "dry soil moisture alone increased the risk of severe heat 6-fold"

Due to the temperature contrasts between the land and ocean and western USA mountain ranges, the north-east pacific is also a region where a wavy jet and blocking high pressure systems frequently form, bringing drought and heat waves to western north America.

Again, looking at temperature anomalies across north America, we see it is part of a wave train with the hot blocking high pressure system centered over Oregon, Washington and western Canada, a cool low-pressure system sitting over central USA and Canada, warm high pressure over northeast America and cooler temperatures over the north Atlantic

The 45.5 degree Celsius temperature in the town of Lytton British Columbia set a new record for Canada, but just barely as the old Canadian record was 45 degrees flat set in 1937.

And although Oregon saw temperatures exceeding 40 degrees Celsius, it was still cooler than Oregon’s record heat of 48.3 Celsius set in 1898.

Climate crisis narratives currently bombarding the public consistently ignore a wealth of science in order to focus blame for heat waves on CO2 global warming! 

Crisis narratives ignore the hotter extremes in our cooler past.    

They ignore the high-pressure systems created by wave train dynamic

Climate crises narratives ignore high pressure system dynamics of 

 1) clearer skies and increased solar heating 

2)  drier surfaces that raise the risk of heat waves 6-fold and more 

3) adiabatic heating that warms temperatures without any added heat energy 

4) and the transport of warmer air into cooler regions

"Attribution science" is a newly created so-called "science" that appears to be just a rubber stamping of the climate crisis narratives as their analyses never fully account for all the contributing factors as good science must, preferring to push a meaningless statistic that a higher average temperature means more extreme weather. It clearly is misinformation

So up next Next: part 6 - How pressure systems control growing and shrinking glaciers

Until then .....

HOW GLOBAL WARMING IS DRIVEN BY THE PACIFIC WARM POOL, LA NINA & ITCZ: AN ALTERNATIVE CLIMATE CHANGE THEORY

 An Alternative Climate Change Theory

Please watch the video at

https://youtu.be/IMH_K8IF-1s

This is PART 4: HOW PRESSURE SYSTEMS CONTROL CLIMATE 

all earlier videos  at

https://www.youtube.com/channel/UC7XNHEz2QCJ_Phf2mvDFk0Q/videos

The transcript for this video is below

Welcome back everyone.

Surprising to many, climate change over the past 10 thousand years has acted completely opposite of what the CO2 hypotheses predicted.

So here in part 4 of my educational video series, I present a much-needed alternative hypothesis that is 100% supported by evidence over the past 10,000 years. I call it the dynamic warm pool, La Niña, Intertropical Convergence Zone hypothesis, or just the Warm Pool Theory for short.

As Rosenthal 2016 has argued, it only requires very small changes in solar heating.

The earth's average temperature is a balance between heating from absorbed solar energy and the rate of cooling as energy is radiated back to space.

The warm pool theory argues ocean dynamics determine the earth's heat storage and heat ventilation and that controls the earth’s rate of cooling.

The function of the warm pool is analogous to a home’s hot water heater and determines how much heat reaches the rest of the world. When a home's hot water heater is fully charged, then there's adequate hot water for every sink, dishwasher, and shower. But drain that hot water heater and you suffer a cold shower. Warmer water gradually returns as the hot water heater recharges.

Likewise, the Little Ice Age drained the warm pool. Now our current warming trend is simply the net effect of a recharging warm pool.

Because oceans can store huge amounts of heat, but the atmosphere cannot, and because the upper 10 feet of the world's oceans contain more heat than the entire atmosphere, solar driven ocean dynamics are truly the climate control knob. The warm pool theory explains the past 10,000 years of climate change, an explanation that CO2 driven climate models have repeatedly failed to account for.

The Indo-Pacific warm pool is often called the heat engine of the world. It is defined by waters that are 28ºC or 82ºF or warmer, and is primarily located in the western Pacific as well as the eastern Indian Ocean

The intense convection over the warm pool drives the region's Hadley circulation and transports heat via the atmosphere from the tropics towards the poles.

Convection requires a minimum ocean surface temperature of 26ºC, and widespread deep convection requires 28ºc or more. Smaller warm pools will generate less convection and thus less global. Warming.

In addition, the strength of the warm pool also determines how much warm water is transported from the tropics to the arctic via several dynamics that integrate into the global conveyor belt.

(One point I didn't emphasize enough in this video but am adding here, is as the re-charging of the warm pool increases heat in the Great Ocean Conveyor Belt, and that heat gets transported into the Arctic, it creates a positive temperature feedback that melts more Arctic sea ice which allows the great quantities of heat stored in the Arctic Ocean to more readily ventilate. It is that short term ventilation of heat that has biased the global average temperature. Like an El Nino event, that heat ventilation paradoxically cools the ocean while warming the air yet this "dynamical warming" is falsely attributed to radiative heating from rising CO2.

There are 4 previous videos that discuss heat transport into the Arctic, the first video is at https://www.youtube.com/watch?v=KNT7oB53pRY&t=88s.

And all 4 can be found at https://www.youtube.com/channel/UC7XNHEz2QCJ_Phf2mvDFk0Q/videos)

It is well established that on average the tropics receive far more solar energy (represented by the blue curve) than the tropics radiate back to space (represented by the red curve).

That's because significant tropical heat is transported to the poles where it is radiated back to space. That transported heat also warms the poles, which become much warmer than by solar radiation alone. Thus, a stronger warm pool generates a higher global average temperature by transporting heat across the globe via convection and the ocean conveyor belt.

Several peer-reviewed papers have examined how the warm pool has changed since the last glacial maximum. The illustration here is from dang 2020.

Despite low CO2 concentrations, temperatures of the warm pool began heating up 25,000 years ago and peaked about 10,000 years ago in a period known as the early Holocene.

Then for the past 10,000 years the oceans cooled until a slight warming trend began over the recent 300 years

In contrast, sea surface temperatures and the global average temperature lagged the warm pool warming,

Suggesting it is deep ocean warming that drive atmospheric warming.

The sun's Milankovitch orbital cycles of obliquity and precession seem to correlate well with the warm pool's long term temperature trends but can’t explain the last few hundred years. Those orbital cycles do not add to the earth's annual insolation. The peak of those cycles in the early Holocene did cause warmer northern hemisphere summers but were balanced by colder winters. In addition, if precession drives global temperatures, our current temperatures should be as cold as they were 22,000 years ago. I introduced the mechanics of these cycles, in part 3 "how the sun and the ITCZ controlled climate and civilization collapses"

Cooling of the Holocene warm pool can be explained by the ITCZ's southward migration that increases El Niño events which ventilate and drain warm pool heat.

The ITCZ integrates global energy inputs and outputs,and accordingly shifts its average location towards the warmest hemisphere. Thus, small changes in solar energy can drive the migration of the ITCZ.

As the ITCZ migrated southward, it increased the frequency of El Niño events that cool the warm pool and contributed to the Holocene cooling trend.

Conversely, it can be inferred that any northward ITCZ shift would result in fewer El Niños and more La Niña-like conditions that heat and enlarge the warm pool.

Although the exact reconstruction of global temperatures varies depending on the models and data that a researcher employs, all agree there has been an 8000-year cooling trend and that is the exact opposite of what CO2 driven climate models simulate.

The erroneous climate models are driven by an 8000-year trend of increasing CO2, which puts those models at odds with evidence-based climate change

In contrast to the Holocene cooling trend, all relevant researchers have found the warm pool has been expanding since 1900.

And this expansion coincides with a more La Niña-like Pacific Ocean with fewer El Niño events than during the Little Ice Age.

 

Here is a closer look at the dynamics that control the warm pool and the effects of the ITCZ and El Niños. Trade wind-driven equatorial currents bring heated water to the warm pool.

These currents are the north equatorial current, designated here as NEC, and 2 branches of the south equatorial current designated SEC.

The equatorial currents generate higher sea levels in the Pacific which pushes warm water through the maze of channels around the islands of the maritime continent, comprising a westward current known as the Indonesian throughflow. Much of that through flow joins the Indian ocean's south equatorial current that is part of the ocean conveyor belt. Some throughflow water circulates through the northern Indian ocean, enhancing an Indian ocean warm pool,

While some flows join the Leeuwin current that flows southward along the west coast of Australia. During a strong La Niña this current is amplified producing what Australians call a Ningaloo Niño.

While the warm pool's overflow through the Indonesian through flow modulates its size, it is the eastward north equatorial counter current that truly controls the warm pool's size which then modulates the throughflow and warming of the ocean conveyor belt, The stronger the north equatorial counter current the more rapidly the warm pool is drained.

The strength of the north Pacific gyre controls the draining of the warm pool.

The gyre is driven by the north trade winds that drive the north equatorial current on the gyre's southern border, while the westerly winds drive the gyre eastward on the gyre's northern border. The north equatorial current contributes a limited amount of water to the warm pool because much of the current veers northward into Kuroshio current bringing added warmth to Alaska.

Since the 1980s, many researchers have reported that a strong gyre drains the warm pool by enhancing the counter current.

Most recently researchers confirmed the connection between the gyre strength, the southward ITCZ migration during the Little Ice Age and an enhanced counter current that drained the Little Ice Age warm pool.

So, what's the role of thee ITCZ? In the age of satellites, the ITCZ is defined by a band of heavy clouds encircling the earth. But centuries ago, sailors identified the ITCZ by the doldrums which stranded many a ship for days and weeks. The ITCZ's vertically rising air creates relatively motionless surface air with no movement to the east, west, north, or south. Thus, the doldrums allow a counter current to flow eastward without being opposed by the westward trade winds 

As a result, a shifting ITCZ can determine the strength of the counter current and size of the warm pool on all time scales from seasons to ice ages. 

The two branches of the south equatorial current provide about 66% of the warm water to the warm pool. Because the ITCZ's average position over the Pacific remains to the north, there is only a very weak south equatorial current, here designated SECC, that sometimes disappears completely. So equatorial counter current has a minimal impact on the warm pool. 

Not only does the ITCZ drive the strong north equatorial counter current but also a deeper eastward undercurrent that drains deeper waters of the warm pool. 

How does the sun and greenhouse warming affect the warmth of the equatorial currents? The warm pool waters originate from the high-pressure regions created by the Hadley circulation. The descending air in those high pressure-systems are dry, and thus few clouds are formed and amplifies solar heating. The lower amounts of water vapor, the major greenhouse gas, also allows more heat waves to escape back to space, reducing any greenhouse warming. So, it is accurate to claim increasing warm pool heat is driven by solar heating. 

All the dynamics in a La Niña-like ocean are illustrated here.    An official La Niña happens when temperatures in the Niño 3.4 regions are at least a half degree Celsius cooler than average for 3 months. Whether during a neutral El Niño Oscillation year or an official La Niña year, the same dynamics increase the warm pool. 

Accordingly, the western Pacific experiences higher sea levels that feed the Indonesian throughflow and ocean conveyor belt. More warm water gets stored deeper in the west Pacific warm pool deepening the thermocline. Strong trade winds cause upwelling of cooler deep waters in the eastern Pacific, causing a large east west temperature gradient of about 6-7 degrees Celsius between the warmer western warm pool and the cooler upwelled waters of the eastern Pacific. That large temperature gradient defines a La Niña-like ocean. This temperature gradient amplifies the trade winds which further reinforces La Niña conditions.

All climate models based on the physics of CO2 warming have predicted that rising CO2 would have little effect on warm pool surface temperatures, arguing CO2 would preferentially warm the eastern Pacific where dryness had reduced greenhouse warming, and thus reduce the temperature gradient But this has not happened, as the large temperature gradient has on average remained or increased in accord with a currently growing warm pool. 

In 2019, Seager published a paper showing that by using different physics, the lack of eastern Pacific warming was consistent with CO2 theory. Apparently, the choice of which science to follow is quite arbitrary So, with amplified trade winds maintaining strong La Niña-like conditions, what triggers the switch to an El Niño every 3 to 7 years. The short answer is the ITCZ 

The ITCZ doldrums enable an amplified eastward equatorial countercurrent that results in El Niños As the ITCZ moves southward the rising air within the ITCZ also triggers the intense convection in the Indian ocean of the 60 to 90-day Madden Julian Oscillation that produces westerly wind bursts Those westerly wind bursts can initiate a kelvin wave of eastward flowing warm pool water. 

The resulting El Niño events then drain the warm pool and cool the ocean's sub-surface waters.    Enough 26+ degree warm pool water moves eastward to also shift the location of intense convection affecting global weather. The warm pool's stored sub-surface heat is brought to the surface in the central and eastern Pacific where it ventilates causing a temporary spike in the global average air temperatures. That reduces the east west temperature gradient, which defines an El Niño-like ocean. A smaller temperature gradient weakens the trade winds reducing the volume of warm water pumped into the warm pool.    Upwelling is reduced, maintaining a warmer eastern Pacific, 

Looking at just the past 2000 years, Oppo's 2009 temperature reconstruction shows the recent warm pool temperatures (shown here in black), began increasing in the 1700s before the rise of industrial CO2. Oppo also compared warm pool trends to Michael Mann’s 2008 global temperature reconstruction, shown in red. Both reconstructions show similar long-term variations except Mann’s last 100 years that he attributes to rising CO2.  However, the warm pool was as warm 1000 years ago during the Medieval Warm Period, as it is today, despite lower CO2 concentrations. 

However, the warmer Medieval warm pool does correlate with a La Niña-like ocean and an ITCZ that was located further north.  

During the Little Ice Age, the warm pool cooled associated with sunspot minimums and the southward migration of the ITCZ. The ocean entered an El-Niño like state, (as indicated by coral proxies from Cobb 2003 and other researchers), indicating ocean dynamics were draining the warm pool. 

 Since the 1700s, as the ITCZ moved back northwards, the ocean experienced fewer ventilating El Niños, and the warm pool began warming and expanding 

So, here's how to interpret a graph of the past 50 years of global average temperatures.  Putting aside changes in land surfaces that also increase temperatures via dynamics such as urban heat islands, the most parsimonious explanation for the observed warming trend is there are currently fewer El Niños than during Little Ice Age, and more La Niña-like years that has increased the heating dynamics to support a growing warm pool. The warming trend simply reflects the recharging of the earth's hot water heater that was drained during the Little Ice Age. 

The transitory air temperature spikes are caused by El Niños discharging stored heat, which temporarily cool the ocean. 

So, what does the future hold? It’s hard to know. The scientific community is divided on predictions regarding more or fewer future El Niños 

But the next few decades should provide some evidence that could refute or support the warm pool hypothesis. So, teach your children to be on the alert and think critically. 

If low solar output continues with low sunspots as some predict, then, if the ITCZ is truly sensitive to such small radiative changes, the ITCZ should move further southward, and temperatures will approach Little Ice Age conditions. 

However, if solar output increases as others predict, the ITCZ should edge northwards, and the warm pool will continue to expand, and temperatures will approach those of the medieval warm period. The good news is since there was no climate crisis one thousand years ago, there won’t be one that happens in the near future, and the effects of CO2 will continue to be insignificant. 

So up next: will be part 5 of how pressure systems control the climate: the cause heatwaves