Climate change: what they were saying, 1974

An early anticipation of a possible climate castastrophy

One of the great books of our time on weather modification and climate change came out in 1974:  Weather and Climate Modification by Wiley-Interscience Press. It was edited by Wilmot N. Hess, Director of the Environmental Research Labs under NOAA.   Hess oversaw 11 ERL programs.   The contributors to this book read like a who’s who of those fields back then.   The discussion of climate and climate change in this volume involves Joseph Smagorinsky on Global Atmospheric Modeling and the Numerical Simulation of Climate, Les Machta and  K. Telegadas on Inadvertent Large Scale Weather Modification, and Helmut Landsberg on Inadvertent Atmospheric Modification through Urbanization–the heat island phenomena.  The book was reviewed by numerous equally outstanding scientists of that era, some of whom are still active today.  In re-reading this volume, meant to bring a sophisticated lay audience up to date on progress in these fields in 1974, I came across this introduction to Section F on global climate, likely written by Hess,  p631-632.  Please pay particular attention to the phrase below, “..the majority of participants…” at the end of the first paragraph.

I only point this out because there has been a bit of an attempt to “re-write history” regarding what our best scientists were thinking in those days when the earth’s temperature was in decline, one that began around 1940 or so, a decline that continued into the 1970s with no explanation and counter to increases in CO2 concentrations of those days.  Much WAS published concerning CO2 and about its global warming affect, but it wasn’t being observed.  Mostly, it was just EASY to perturb the atmosphere in the crude models with something like CO2 with its well-known radiative attributes, hence, maybe get a publication.   However, not much else was known about what perturbed the exceedingly complex global climate system and caused the modest temperature meanderings, such as those shown in the third insert.

Yes, its true.   Back then (late 60s into the 70s) we were starting to think about global cooling in a visceral way based on obs.

When I say, “we”,  I am not referring to myself; I was merely a forecaster-meteorologist with in a large randomized cloud seeding experiment in those days in Durango, Colorado.  Weather and Climate Modification was important to me in the years after 1974 because of the sections on cloud seeding, not because of the climate change discussion here which I have re-discovered.  (Please excuse the highlighting, done decades ago.)

Below (third insert) is the northern and southern hemisphere’s mean temperature record as deduced by NOAA’s J. Murray Mitchell in those days; these charts appear on  p719 of this volume, and were well known at the time.  Its easy to see from these graphs why there was so much concern about global cooling in those days when you look at the decline in both hemispheric temperatures after 1940.


Another bit of interest today is the essay by Machta and Telegadas (Chapter 19, p687) in this book.  Their essay concludes with a summary by H. H. Lamb  (a well-known East Anglia University climate researcher) that contains predictions of NATURAL (emphasized by the present writer)  climatic changes and a brief evaluation of those predictions.

What was particularly remarkable was the evaluation, apparently by Lamb, in the section, “Actual Forecasts“.   In this section, seven attempts to forecast the future climate from periodicities deduced in past data are briefly evaluated.   In today’s lingo, some of these efforts might be called early detections of pressure “oscillations”, that is,  shifts in modes of circulation patterns, where high and low pressures like to reside (footnote).  These “actual forecasts”, ones that appeared in the journal literature, were based on such parameters as changes in circulation patterns deduced over decades, patterns in oxygen and hydrogen isotope ratios in ice cores that were then subject to Fourier analysis,  climate forecasts based on projected sunspot activity, another on particle radiation from expected solar flares, patterns of “meridionality” or, north and south components in the wind, and “local” circulation patterns over Europe, and that latter in a paper published in 1939!  And, of course, the old standby,  tree ring patterns, again looking for harmonics or cycles in those data.   Most of this kind work, deducing cycles in past data in the way that it was done in these papers would be taken with a grain of salt, or not taken seriously at all.

SO, WHY even mention these studies?

Lamb finds most of the predictions were CORRECT in anticipating the colder weather ahead over coming decades after these studies were published!  Its really stupefying to read this section today and see an assessment of “correct” assigned to these forecasts based on no real underlying physical mechanism, such as why did the wind, the pressure pattern change, or on sunspots?  (It was interesting to note that the sunspot based forecast was deemed “correct” for weather, but totally wrong on sunspot activity!)

Well, it does make one wonder how these forecasts could have been correct.  Were a few researchers on to something that we have missed, or have also “re-discovered”, framing our findings today in more sophisticated terms such as “oscillations” instead of “cycles”?

Or were these forecasts “correct” because they were the only ones of hundreds of such forecasts (in which it would be expected that a few would be “correct” just by chance)?   The authors of this Chapter 19 do not divulge how many forecasts were examined.

However, those early forecasts based on circulation pattern changes over decades, should grab the attention of today’s “oscillators” if they haven’t already.


Footnote:  It sometimes seems as though almost every climate researcher today has his own personal “oscillation”, from the Pacific Decadal Oscillation, North Atlantic Oscillation, Arctic Oscillation, Southern Oscillation, on and on.  More will be reported.  (Maybe I should have one!)  ((Actually, I do have my own climate oscillation, but its not been published, probably never will be.))