Is the climate changing?  Yes.  Is mankind contributing to the change in climate?  Yes.  Should major national policy respond to this change?  No!

Climate changes continuously, both warming and cooling.  There is nothing new in this and probably nothing to get excited about.  Man inevitably modifies the climate.  The only questions are by how much and in which way.  Historically, man has modified the landscape sufficiently to make a noticeable impact on the climate.  The essential question we must address is, how much are we, today, impacting the climate, and is that impact harmful?

The answer is we don't know!  My suspicion is that we have had only a modest, and probably benign, influence. 

Given that we don't know, it is seriously bad policy to imperil our future in an attempt to control the climate.  It also smacks of hubris to believe we have that much control over Mother Nature.

Before we look at the current situation, let us consider how man influenced climate in the past.  In prehistoric times, the Mediterranean area was well forested.  During the Neolithic period, wild goats were domesticated.  The proliferation of domesticated goats caused major damage to the vegetation around the Mediterranean basin and beyond.  Much of the land became deforested.

A second example is northern Europe.  Once these lands were heavily forested.  With the invention of the horse collar and the wheeled plow during the Middle Ages, it became possible to efficiently turn the heavy soil in northern Europe.  As a result, the woodlands there were rapidly cleared for farming.  Europe today looks very different from the Europe of two thousand years ago. 

These modifications of the landscape changed the rates of water exchange with the atmosphere and the local reflective albedo.  Modification of the regional climate was the inevitable consequence.  What impact these regional climate modifications have had on the rest of the world's climate is unknown, but it may be significant. 

Obviously, we have successfully adapted to these changes.  And certainly, no one is proposing that we restore Europe, South Asia, and North Africa to pre-Neolithic conditions.  Moreover, man's past impacts on the climate pale in comparison to natural climate variation, as we shall see.

Today, the climate debate is highly politicized.   A powerful establishment is attempting to deindustrialize America in response to a hypothetical global warming crisis.  This establishment uses the predictions of a certain class of climate models as its excuse to suppress our individual liberties and reduce our standard of living.  Do they have a valid case?  Let us examine the science to see.

We must consider climate models because their outputs are driving the politics.  I am a physicist, not a climatologist.  I do not know the internal details of the climate models.  I don't have to.  All I need is an understanding of the limits of computer models and their proper application.  In this, I have copious experience.

The first thing to understand about models is that they are not nature.  They are tautologies.  They only tell you the consequences of your assumptions.  Get the assumptions right, and a model has substantial predictive ability.  Mathematically expressed quantum mechanics is marvelously predictive.  So is general relativity.  Climate models aren't even close.  In a computer model, get any one of its assumptions wrong, and the model no longer can predict.  It is evident from the incorrect predictions of the complex climate models that one, or more, of the many built-in assumptions are wrong.

How do we know this?  They can't predict the past!  Earth perpetually undergoes a complex choreography of change.  Variations in Earth's orbit combine with precession and nutation of the poles, and the dance of colliding continents, to modify the climate in historical, as well as geological, times.  Then, too, the sun is a variable star, and its changing moods profoundly influence our climate.

Since the warmth burst that ended the last ice age glaciation, the world's climate has been steadily cooling.  Superimposed on this cooling trend are significant fluctuations.  The Minoan warming was followed by the long winter that caused the Bronze Age collapse.  The Roman climate optimum declined to the cold-caused age of migrations and the fall of the Western Roman Empire.  The High Middle Ages that followed were substantially warmer than today.  We are still recovering from the severe "Little Ice Age" that ended the Middle Ages optimum.  Our current warming trend is, probably in major part, the recovery from that centuries-long cold spell

All of this is well known.  Unfortunately for climatologists, their computer models cannot account for these known climate fluctuations.  Something unknown is actually controlling.

There is more.  Starting around 5,000 years ago, a major change in the world's climate began.  The West African monsoon began its migration south.  This also influenced the Indian Ocean monsoons.  The Sahara started drying out.  The culminating crisis, with civilization collapse, occurred about 2200 B.C.  It was signaled by a major reduction in the flow of the Nile.  The monsoon migration had suddenly accelerated.  In Egypt, the Old Kingdom disintegrated into centuries of anarchy.  In Mesopotamia, the Akkadian Empire fell.  Harappan civilization in the Indus Valley was nearly destroyed.  Climatologists have tried hard to explain the shift in the monsoons.  But they have failed.  Something is seriously wrong with their models.

Richard Feynman gave us this dictum: "It doesn't matter how beautiful your theory is, it doesn't matter how smart you are.  If it doesn't agree with the experiment, it's wrong." 

It isn't just that the climate models are demonstrably wrong.  There has been substantial cheating as well.  The Golden Rule is in play here: "He who has the gold rules."  The Establishment recognized that "climate crisis" gives them much more power, and they have the gold.  To survive professionally, everyone must fall in line to make it so.  Science is not a monastery filled with saints — some willingly cheat. 

The cheating has taken multiple forms: the U.S. government, politically motivated, has deliberately shut down temperature monitoring stations in natural woodland settings and relied entirely on similar stations in urban heat islands.  Naturally, this imposed bias in siting the measurement apparatus delivers apparent warming.

Major scientific journals have been captured by the climate crisis crowd.  Censorship reigns.  Only orthodox articles are published.  The absence of contrary published research is taken as verification that the climate really is in crisis.

Climate modelers adjust their many controlling parameters to "curve fit" their models to the last few decades.  This is analogous to fitting a polynomial to data.  In this regard, mathematician John von Neumann sarcastically observed: "Give me four parameters and I will give you an elephant."  The problem with curve fitting is that the fit blows up outside the fitted region.  We see exactly this with all of the major climate models.  They all have predicted a rapid rise in temperature that just hasn't happened.

Yet another problem is the assumption that the sun is constant.  This isn't unreasonable because the modelers don't know what to do with the sun.  The reality is that the sun blasts the Earth in a variable solar wind of great power.  This blows around our magnetic field, which, in turn, modulates our atmosphere.  Moreover, the influx of cloud nucleating cosmic rays is also affected by the sun's variability.  How can the climate models successfully predict the future when these powerful effects are not understood and are therefore ignored?

Finally, the influence of carbon dioxide on the climate is likely way over-estimated.  Carbon dioxide is a very minor contributor to the greenhouse effect; water vapor overwhelmingly dominates.  The lower atmosphere is already opaque with carbon dioxide.  Adding still more means little. 

Besides, carbon dioxide is an essential plant nutrient.  Horticulturists tell us that plants flourish in a carbon-rich environment.  Commercial greenhouses deliberately increase their carbon dioxide.  Conversely, during the Ice Ages, the bitter cold oceans absorbed much of the atmosphere's carbon dioxide.  The levels got so low that most plant life was pushed into starvation mode.

So it is reasonable to treat the climate disaster predictions with great skepticism.  It is also reasonable to recognize that the Powers that Be likely have a nefarious agenda.  So it is best to reject "climate crisis."  Don't take this wooden nickel! 

Image via Pxhere.