Can a few degrees of global temperature change make a big difference?

It is rare to get fact-based comments from Leftists on any of my blogs.  As other conservative bloggers will confirm, enraged and irrational abuse is what one normally gets.  Which tells you a lot about the Green/Left.  Their rage and hate make the horrors of Soviet Russia and Maoist China understandable.

So I was surprised and interested to find that, although he was abusive, one commenter did actually make an apparently rational argument. He said:  "The average global temp of the last ice age was only a few degrees cooler than the 20th century".  And from that he argued that a few degrees of change is all that is needed for big effects in general.  So a few degrees of warming could also  have a big effect.  As we know, Warmists have quite arbitrarily set a temperature rise of 2 degrees Celsius as the knell of doom so are they right?  Could even that small change have a big effect?

But does that argument hold up?  If a few degrees of cooling made a big difference, would a few degrees of warming also make a big difference?  I think we can all see instinctively that "It ain't necessarily so" but let me flesh that perception out.

The earth as a whole is actually a rather cold place relative to the freezing point of water (zero degrees Celsius). The average global temperature at present is approximately 14 degrees Celsius.  And the average global temperature in the last ice age was around 9 degrees Celsius.  So the difference is only 5 degrees -- which does indeed sound alarming.

But any average implies a range above and below it so an average of 14 degrees will mean that there are a lot of places where the number is a lot lower than that.  An average of 14 degrees tells us that there will be a lot of places on earth where the temperature is a lot cooler than that. For circumpolar regions, the temperature will be getting close to zero degrees.

So that makes it very clear why we had an ice age.  Lots of the globe was already pretty cold so a drop of 5 degrees pulled a great part of it below the threshold for ice formation (zero degrees Celsius).

But there is no similar situation for warming.  A couple of degrees of warming is unlikely to cause anything to cross any threshold. It might melt a bit of sea ice but melting floating ice leaves the water level unaffected -- As Archimedes demonstrated about 3,000 year ago.

So yes.  A few degrees can make a big difference but only if you are near some threshold -- and it has not been shown that we are.

FOOTNOTE:  My academic background is in the social sciences.  I am no paleoclimatologist.  So when I first saw the argument by the Warmist, I was nonplussed.  I could see that the argument was invalid but I could not put my finger on why.  But my research background kicked in immediately and I said to myself: "What are the numbers?"  And when I looked up the numbers, I had the answer to the puzzle.  In science, the numbers make all the difference.

And the numbers make a lot of Warmism look absurd.  The annual announcements that the year just past was the "hottest", "third hottest" etc. sound important until you realize that the differences being talked about are in hundredths of one degree only. We actually live in an era of exceptional temperature stability.  It takes the perversity of the Left to call it an era of dangerous warming

Technical note:  I have given 9 degrees as the temperature of the last ice age but that is very much an approximation. It is however a fairly conventional approximation and serves well for the purposes of illustration. There are lower figures, depending on how you balance out the different times and places in the era concerned.  And the whole concept of an average temperature for the earth is a pretty hairy one anyway. -- JR.


3 comments:

  1. OK, good point about there being a threshold concerning the iceage.

    The arbitrary 2 degrees was set because it is well below any thresholds. Their main concern is positive feedbacks into the system causing accelerated GW. Things like increased water vapour, decreased CO2 solubility in the oceans, methane released from permafrosts, the melting of sea ice which affects the amount of radiation absorbed by the oceans, etc etc. The thinking is that at the 2% mark the world falls short of tipping the balance in favour of these feed back loops. Maybe it errs on the side of caution I don't know.
    Some unrelated points if you don't mind:
    1. Given some of the images we've seen lately of India and China's air quality; why wouldn't there be more call for stricter air pollution reductions, and an increase in alternative energy resources/research. Even if you don't believe CO2 is a badun (keep in mind that CO2 also affects the oceans with increased acidity).
    2. Leftists are not the only angry and abusive ones (try reading the comments section of Newsmax for example). Your oversimplified dichotomy of left and right is too simple to be real. And to think that the horrors of Russia and China can be understood by the comments of leftists is pure hyperbole. The same hyperbole can be used to explain the rise of Hitler when reading conservative comments (especially the Trump supporters)
    3. What makes you think the commenter you are referring to is male?

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  2. I am no scientist, and I know nothing about climate science. But I am well trained and practiced in dialectical rational emotive therapies and tactics, and I have worked the most extreme environments and cases of psychopathy, addictions, PTSD,... just about all human maladaptive, psychological and psychiatric conditions. Observing individuals and groups, their driving priorities, patterns of thought, emotion and behaviour, their mental-emotional "shape", gauge their degree of intelligence and scope and fineness of cognitive ability, their criminogenic/psychopathic inclinations, and the flow of initiative, influence and power through the component parts of their psychological makeup or power train within them as individuals and through them as groups, then tactically cause to come together opposing and incompatible elements so as to catalyse or initiate a reactive or conscious change, such as reduction in one element and improved positioning and increased strength of another is what I do. People patterns are what I work with. So I simply observe and listen to people, looking through the surface subject matter of which I may know nothing about and observe the underlying drivers, patterns, priorities and values, and work with those. And it is that skill that causes me to doubt the claims of most global warming proponents. It is apparent to me that many are manipulators and deceivers, and more are deceived themselves.

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  3. Regarding John saying: "So that makes it very clear why we had an ice age. Lots of the globe was already pretty cold so a drop of 5 degrees pulled a great part of it below the threshold for ice formation (zero degrees Celsius).

    But there is no similar situation for warming. A couple of degrees of warming is unlikely to cause anything to cross any threshold. It might melt a bit of sea ice but melting floating ice leaves the water level unaffected -- As Archimedes demonstrated about 3,000 year ago.

    So yes. A few degrees can make a big difference but only if you are near some threshold -- and it has not been shown that we are."


    I am not agreeing with the warmists. Most ardent warmists I meet are lefties and suffer from irrational beliefs, delusions and projections. Whether the planet is dangerously warming due to man's influence I don't know. It could be, but I don't personally put much weight in what warmists say unless I perceive rationality and evident integrity. Often I don't.

    But I do wonder if there might exist an upper global average temperature threshold at which insufficient planetary ice becomes detrimental to life as we know it on the planet.

    The following is just a thought, one which those who know more about climate science than I do might wish to dispute or perhaps even consider plausible. I will be interested in other's responses:

    Within a reasonably enclosed system finer degrees are always present between greater degrees, but not necessarily present outside of them. It is the greatest differences, the polarities, the ends of the spectrum or the opposite forces, that enclose and drive the system.

    Perhaps, in relation to a planet's geographical size and its atmospheric size and amount of water and other factors, a certain amount of ice is required on a planet for the planet to maintain a water cycle, even to retain its water. And perhaps below that threshold or proportion of ice the planetary water cycle ceases. Perhaps the water cycle is driven as much by the Earth's ice as it is by the Sun's heat.

    Condensation of water vapour requires temperature variation, for water vapour needs to be chilled to condense. Perhaps condensation and precipitation is part of what stops too much water vapour escaping into space. If not all of it, must at least be a major part of that prevention. And perhaps a bank of coldness such as the polar icecaps is required to create a suitable upper atmospheric chilling layer to condense water vapour into clouds. Naturally other things contribute to cloud formation and rainfall too, like atmospheric dust and geographical formations, but I am considering the most outside or extreme causes or polarities that might drive the system, and between which other factors are mere facilitators.

    The water cycle requires heat and convection, and also a chill factor. Might sufficient chill factor be dependent on a sufficient volume of ice, a chill bank? Without which, water vapour might more easily pass through the upper atmospheric layers and escape into space, perhaps even until no water is left on the planet?

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