The media is exaggerating about heat waves, claiming that global warming/climate change caused by anthropogenic CO2 emissions is creating a large and sudden increase in major heatwaves. The largest in historical record. Heat waves are everywhere on the planet! Phoenix, Arizona is an often-noticed poster child of the new heatwave regime.
Here are a few examples of titles, I could provide dozens more like them.
Tests
Before discussing this situation, let me introduce two possibilities for you to consider.
(first) Human greenhouse gas emissions, such as CO2, are gradually warming the planet. Over the past century, the Earth has warmed by about 1°C, and human emissions may contribute much (but not all) to the warming. The El Nino period contributes to temporary warming, and localized warming due to urbanization (urban heat island) is also important. Most heatwaves are largely natural, with minor enhancements from global warming/climate.
(2) Heat waves are mainly forced by increasing greenhouse gases. The entire planet is experiencing unparalleled heat due to human-caused climate change. By reducing greenhouse gas emissions, heat waves can be greatly attenuated or prevented.
Which answer do you think is correct? One supported by observations and peer-reviewed science?
The correct answer is (1). Heat waves are mainly caused by natural variability, with humans enhancing them by small amounts. Let me prove it to you and describe some of the hype and deception going on in the media and by others.
It’s important to understand that current heatwaves are local, with significant parts of the planet also experiencing cooler-than-normal conditions. Most of the planet does NOT experience unusual warmth.
Consider the temperature pattern observed on Tuesday night at 11 p.m., or more precisely, the difference in temperature observed from normal (see below). The red areas are above normal and the blue/green areas are below normal.
The figures show that Earth had BOTH heatwaves and cold spells going on at the time.
For example, the Southwestern United States. warm, while much of the eastern United States was colder than usual. Northern Europe is cold, while southern Italy is hot.
So heat waves are local (and transient) conditions, and only a small part of the globe experiences unusual warmth. Greenhouse warming from greenhouse gases is much more uniform.
So what is causing the local warming? The answer is obvious if we plot the higher level map (for 500 hPa, about 18,000 ft) at the same time (see below). Blue areas indicate drop (low pressure) and red areas indicate ripple (high pressure).
The warm areas are closely related to the upper areas and cool to the upper floor grooves. Ridging is related to air sinking and warming. Contrast with trough. Ridges and trenches also have wind patterns that can move the tropics toward the poles (and vice versa).
Such wave patterns are quite natural. There is no convincing evidence that the atmosphere becomes more wavy (thus more heat and cold waves) under global warming. I have read all the literature on this and have self-published on the subject in peer-reviewed literature.
The ripple of the upper runoff is particularly high this winter and spring, creating enhanced cooling in some areas and warming in others. For example, conditions are cool/wet in California and warm in southern Canada.
I repeat: there is no reason to think that this oscillation is not a manifestation of natural variability of the atmosphere.
With the planet’s overall temperature gradually increasing due to human greenhouse gas emissions (about 1°C), the heat wave will be about 1°C warmer and the cold wave about 1°C weaker.
This is Exactly what is observed.
By the way, extreme cold kills A LOT more people per year than heat waves, so global warming is actually reducing deaths from extreme heat (you won’t hear a lot about this in the media!)
But there’s something else that’s ramping up warming right now.
This spring, El Nino flares up rapidly and El Nino warms the planet! Here are the main markers of El Nino: the temperature in the central tropical Pacific (3.4 Nino zone). Warming is VERY fast and early in April and May.
The oscillation between El Nino and La Nina (cold water), is a natural pattern of atmospheric variation.
Would we have major heatwaves without man-made global warming?
You bet we will. We’ve certainly had significant heat waves (some stronger or stronger this month) in the past (in the 1930s, for example). Will the heat waves this week increase slightly (like 1°C) due to global warming. Entirely possible. So a place like Phoenix would have a high temperature of 115F instead of 117F. Pretty much the same effect.
Media Deception About Phoenix, Arizona
The media has been particularly concerned about the recent heatwave in Phoenix, in which they are leading the record for the number of days above 110F.
As I will describe below, there is much deception going on here. 110 degree approach is one good example of misinformationand the temperature record in Phoenix is highly questionable because of massive growth and the massive urban heat island effect.
Statistics “Picking cherries”
The term cherry picking can be defined (Wikipedia) as:
cherry picking, proof suppressionor error of incomplete evidenceis the act of pointing to individual cases or data that appear to confirm a particular position while ignoring a substantial portion of possibly conflicting similar and related cases or data that location.
The media and some climate activist groups have advertised that Phoenix has now exceeded 110F a number of times in a row. So something unusual and scary is happening.
But why 110F? Do you have questions about that?
They did this on purpose because if they chose a different temperature, they would get a completely different answer, one where Phoenix wasn’t unusually warm.
Consider choosing a difference of two degrees (112F). This year dropped to 6th place!
How about something more unusual (115F)? 2023 dropped to 8th place
Or consider the more “garden variety” temperatures (105F). This year still in 8th place.
Do you feel cheated and cheated? This is a deliberate attempt to pick cherry stats to advance an agenda. Not good.
But choosing Phoenix is worse than that.
Phoenix is perhaps the fastest growing and strongest urban heat island in the nation.
Phoenix is one of the fastest growing cities in the United States (see below) and all construction (concrete, buildings, heat sources) leads to profound warming, a phenomenon known as urban heat island effect.
Want to see Phoenix’s heat island in action this week?
Here are the temperatures late Tuesday afternoon. 117F at Phoenix airport but 111F just outside the metro area. This difference is quite typical for the city.
So, even without global warming, Phoenix’s temperature would increase dramatically over time due to the city’s rapid growth. Such urban heat island effects severely degrade temperature records, creating anthropogenic warming.
Finally, let me note that although the Earth is gradually warming due to anthropogenic warming, There is no evidence that the heat wave is being amplified or enhanced by this base warming. So all the bewildering headlines are really worthless.
Want to see an example of this? Here are the annual highs in Olympia, Washington, with a linear trendline added for your benefit. The annual high temperature has increased by about 2F, akin to a global warming signal.
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The claim that a sudden and rapid increase in heat waves is occurring due to global warming may be tempting bait for the media and a powerful tool for climate activists, but that is simply not true.
Finally, let me note that the headlines earlier this month that the Earth is warmer than any period during the past 125,000 years are really meaningless. But I will leave that discussion to another blog.
