Climate scientists agree any imbalance between the earth’s absorption and release of energy can cause climate change.
However, the question is how much of that imbalance is caused by ocean dynamics vs increasing CO2 concentrations. This video explains how La Ninas and El Ninos can drive the earth’s energy imbalance by storing heat in the ocean, and why this natural explanation of global warming is superior to blaming greenhouse gases.
Today in part 3 of the big 5 natural causes of climate change, I want to demonstrate how more frequent La Ninas have warmed the world
La Ninas promote clear skies over the eastern pacific increasing solar heating. As a result, the eastern Pacific absorbs over 100 watts per meter squared more solar energy than it releases back to space. A similar but smaller energy imbalance occurs in the eastern Atlantic during Atlantic Ninas
The blue regions release more energy back to space than their surfaces absorbed. That excess energy was initially absorbed and transported from the tropics. Climate scientists agree any imbalance between the earth’s absorption and release of energy can cause climate change.
However, the question is how much of that imbalance is caused by ocean dynamics vs increasing CO2 concentrations
In all peer-reviewed research the world’s energy budget is measured in terms of watts, the flow energy per second. For example, a burning candle emits 80 watts. But step just one meter away from that candle and you will not feel its heat. So, to express the effects of heat energy, heat is measured in the amount of watts reaching a square meter of surface area, or watts per meter squared.
On average, the earth’s atmosphere and surfaces absorb 240 watts per meter squared of solar energy.
Claims of a climate crisis, are based on the belief that CO2 is causing the earth to retain just one more watt of solar energy than it releases back to space
But natural ocean dynamics also cause the earth to retain more absorbed solar energy than it releases back to space
The greatest amount of heat absorption happens when the pacific is in its neutral condition or a La Nina-like state which is simply a more extreme neutral state.
The trade winds blow warm waters across the Pacific and concentrate them in the western Pacific and Indian Ocean creating the warmest body of water on earth, the Indo-Pacific Warm Pool
That removal of water from the eastern Pacific allows cool sub-surface waters to upwell there. The cooler temperatures generate fewer clouds which increases the absorption of solar energy by 15 watts per meter squared
Furthermore, the resulting east to west temperature difference amplifies the trade winds causing positive feedback that favors maintaining La Nina like conditions.
Strong trade winds cause more heated water to be stored deeper in the western pacific where the heat is inhibited from ventilating back to space.
Climate scientists are fully aware that this dynamic increases ocean warming, but only bring it to the public’s attention when they blame the ocean for creating a hiatus in the rise of global average temperatures that contradicts simplistically based predictions of warming driven by rising CO2.
James Hansen is considered the godfather of the climate crisis. Initially he studied the climate on Venus, which is lifeless and devoid of water. So naturally his analyses and models of climate change are typically focused on greenhouse gases that affected Venus.
To his credit, Hansen admits this bias in his 2005 paper stating “our climate model is driven mainly by increasing human-made greenhouse gases and aerosols”
But Hansen also realized that regards the earth’s climate, “one may find other combinations that yield warming comparable to that of the past century”
An increasing understanding of the effects of El Ninos and La Ninas is providing such an alternative combination of effects and a comparable alternative explanation for the warming that Hansen and his acolytes blame on CO2.
Hansen didn’t carefully examine those ENSO effects because as he stated his “coarse-resolution ocean models had been unable to simulate climate variations associated with El Nino–Southern Oscillation processes”
Now the improving understanding of El Nino & La Nina effects will likely cause the CO2 driven climate crisis claims to fall like a house of cards
Climate scientists have calculated the earth’s energy budget, but it is plagued with large uncertainties. However, when trying to convince the public that their science is settled, illustrations such as this one posted by NASA, hide all those uncertainties.
Fortunately, the budget calculations by Stephens 2012 exhibited more integrity and highlighted those uncertainties.
Nasa’s yellow arrows show incoming absorbed and outgoing reflected solar radiation Nasa’s red arrows show the outgoing infrared and the back radiation from greenhouse gases that recycle the infrared and delay the rate of the earth’s cooling
Nonetheless, eventually nearly all the infrared energy escapes back to space. Except an estimated mere 0.6 watts per meter squared, but with an uncertainty of + or – 0.4 watts
Regards how much energy the ocean stores and releases. The uncertainty is huge. The uncertainty of the cooling effects by evaporation alone, or latent heat, is + or – 10 watts, overwhelming the estimate of a CO2 driven energy imbalance.
During the Little Ice Age, the oceans cooled for about 400 years. The Pacific was mostly in a persistent El Nino-like state, a condition that reduces how much heat is stored at depth relative to a La Nina like state. Solar minimums reduced the trade winds which the El Nino like state further weakened.
One result of an El Nino-like ocean is the reduction of upwelling that brings nutrients to the sunlit layers. Thus, during the little ice age the pacific exhibited low biological productivity.
Then in the early 1800s as solar irradiance rose the ocean entered a more La Nina like state, increasing upwelling and ocean productivity.
A switch to a more persistent La Nina-like state amplifies the trade winds and raises sea levels in the western Pacific. Accordingly, between 1993 and 2010 satellites observed western pacific sea levels rising many times higher than the global average.
The stronger winds of an La Nina-like state drive more warm water into the western Pacific, increasing the size and the depth of the Indo-Pacific Warm Pool. The warm pool’s growing heat is then transported around the world.
Oceans can warm just by reducing the overall cooling rate even if there is no increase in absorbed heat.
During La Ninas, more heat is stored at depths, typically up to 200 meters, and those depths inhibit ventilation of that heat.
But the estimated 3 Watts/m2 of infrared heat from the back-radiation of greenhouse gases, never penetrates more than a couple of microns below the surface.
For reference, a human hair is about 70 microns thick. And 1000 microns equal just one millimeter
In contrast hundreds of watts from sunlight energy can penetrate 10 million times deeper. Depending on how clear the water is, the shorter wavelengths of sunlight can penetrate to 100-meter depths.
In general, a steady cooling of the ocean is controlled by a one-millimeter-thick layer at the surface. In addition, storms like hurricanes will episodically pull heat from the deeper layers.
Depending on depth of sunlight penetration, a layer up to 100 meters thick warms the ocean each day.
But that absorbed heat can only radiate away via the surface gateway that is less than 100 microns thick, termed the electromagnetic skin layer
In addition, heat can leave the ocean via contact with the air or via evaporation, which only happens from the 100-micron thick layer termed, the thermal skin layer
Because this upper layer is always losing heat, it is cooler than the diurnal warm layer below and is sometimes called the cool skin layer. This cooler skin surface ensures the flow of heat is almost always from the warmer ocean layers back into the atmosphere.
As a result, the micron thick layer that absorbs greenhouse infrared is always ventilating any absorbed heat back to the atmosphere, in contrast to the deeper and warmer solar heated layer.
So, it seems virtually certain that any change in ocean warming must be driven by solar changes, and not from any changing concentrations of greenhouse gases.
During an El Nino event hot water in the western warm pool sloshes eastward across the pacific. Heated waters that had been stored at depths in the west is brought closer to the surface in the east. Where strong evaporation ventilates a portion of that heat and cools the ocean.
As that warm pool-heat then warms the eastern Pacific, it also reduces the trade winds, and sometimes, even reverses the trade winds’ direction creating feedback that prolongs an El Nino-like state.
Largely governed by the winds, the amount of transported hot water varies from year to year. In the 1600s, Peruvian fisherman named that warm water arrival “El Nino”, referring to baby Jesus, because the flow of warm water arrived each year around Christmas time.
Because El Ninos and La Ninas affect the winds and the jet streams and thus extreme weather patterns as detailed in part 2 of this series, to improve weather forecasting scientists measure changes in temperature within the Nino 3.4 area for statistical purposes.
When temperatures rise 0.5 degrees Celsius above average for about 5 months, an El Nino is declared. When temperatures drop 0.5 degrees Celsius below average a La Nina event is declared. The greater the departure from average the stronger the events effects.
Scientists also classify El Ninos according to the varying distance across the pacific that the heated water travels
Graphs of the globally averaged air temperatures are very sensitive to the heat released by El Ninos.
El Ninos are clearly seen as temperature spikes.
To naive journalists and the general public such warm spikes appear to confirm the coming global warming crisis. But such graphs obscure real climate dynamics As Kevin Trenberth, a chief architect of global warming theory admits, El Ninos are not just temporarily ventilating ocean heat, but cooling the earth’s entire climate.
On the other hand, the cooler temperatures in the graph are associated with neutral conditions and La Ninas due to the upwelling of cold subsurface waters. Paradoxically that’s when the ocean is warming.
Clearly because natural El Ninos and La Ninas have such critical effects on climate change, we would expect much more of the earth’s warming to be attributed to ENSO dynamics.
But the reason CO2 gets the blame instead is quite clear. After more than a decade since James Hansen admitted the inability of climate models to reproduce El Nino La Nina ocean dynamics, climate models still do not accurately simulate them. As published by climate scientists Michael Mayer, Trenberth, and others in 2016
“All climate models greatly underestimate changes in Pacific Ocean heat content”
“And climate models underestimate the redistribution of heated waters between varying depths and between the eastern and western ocean.
“So, it is highly likely that climate models also underestimate La Nina’s contributions to the steady increase of heat in the Indo-Pacific Warm Pool as well as underestimating the century rise in the average global temperature since the little ice age termination when the pacific entered a more La Nina like state.
Although an El Nino event lasts for about a year, its redistribution of heated water has much longer lasting effects associated with the pacific decadal oscillation
The heated water that sloshed to the eastern pacific doesn’t completely cool, causing the eastern tropical pacific to remain abnormally warm for 20 to 30 years. The reduced trade winds and other circulation changes reduce transport of warm waters to the northern pacific making it abnormally cool. This pattern of ocean surface temperatures is labeled the positive phase of the pacific decadal oscillation and strongly alters weather patterns, especially for western north America
As an El Nino’s residual warm waters continue to cool or get transported back to the western pacific, the trade winds gradually increase, and the resulting upwelling cools the eastern pacific further. Circulation changes now pump more warm water into the northern pacific. The resulting reversed temperature pattern is called the negative phase of the Pacific Decadal Oscillation and it amplifies the wavy jet stream over western North America increasing the probability of drought and heat waves.
The net increase in warm pool and global temperatures can be explained by an El Nino/La Nina Amplification effect
During an El Nino, heated warm pool water moves eastward primarily along the North Equatorial Counter Current.
As El Nino gives way to more neutral and La Nina conditions, much of El Nino’s residual warm water then re-circulates back to the warm pool via the north equatorial current and is reheated. This reheated water is slightly warmer than the heated cold-upwelled waters that largely fill the warm pool.
Some of that reheated water also circulates northward to warm the northern pacific.
An independent climate researcher and author, Bob Tisdale, was the first to recognize the higher temperature effects resulting from a La Nina-like state reheating residual warm waters from an El Nino event.
The re-circulation and re-heating of residual warm El Nino waters results in a gradual stepwise warming of ocean temperatures after each El Nino event.
The accumulating heat in the warm pool, then feeds the Ocean Conveyor Belt that transports that heat into the Indian Ocean, then the Atlantic and up into the Arctic as illustrated by the red loop.
Higher sea levels in the western Pacific during La Ninas help push warm pool waters into the Indian Ocean. A portion of those waters are further heated in the Indian Ocean, which then get transported around southern Africa into the Atlantic – a dynamic referred to as the Agulhas leakage.
Recent studies have detailed the pathway of Agulhas Leakage water into the Arctic
First across the southern Atlantic, then across northern brazil’s coast and into the Caribbean, then up the east coast of North America and into the Arctic – linking La Nina warming to Arctic sea ice fluctuations
Oscillations in the Agulhas Leakage correlate with the Atlantic Multidecadal Oscillation, which correlates with lost arctic sea ice, as detailed in part one of this series. That lost ice allowed more stored Arctic heat to ventilate and increase the global temperature much like the ventilation of deep warm pool waters also raises global temperatures.
As Hansen unintentionally predicted in 2006: “other combinations” such as discussed here, the transport of solar heated waters heated by more frequent La Nina events, can yield alternative causes that explain a comparable warming.
Up next: part 4 of the big 5 natural causes of climate change: landscape changes
Until then embrace renowned scientist Thomas Huxley’s advice: “skepticism is the highest of duties; blind faith the one unpardonable sin”
Jim Steele is Director emeritus of San Francisco State University’s Sierra Nevada Field Campus, authored Landscapes and Cycles: An Environmentalist’s Journey to Climate Skepticism, and proud member of the CO2 Coalition.