CLIMATE CHANGE: HOW THE ORTHODOXY CHANGED 1974-2007
The following quotations are extracted from the Encyclopaedia Britannica article on climate change in its 1974 version.
The conclusion of the article is that:
“A warm up began in the mid 1880’s and reached its climax about 1940’s; by 1955 temperature trends had generally been reversed, and during the 1960’s there was a distinct cooling trend.”
and the forecast was:
“Winters will more often than not be colder and snowier than average, and more summers will be either cool or wet.”
The prognosis for climate as predicted by one of the best experts in the field in the mid 1970’s was therefore for a colder climate.
This does not mean that today’s climate experts’ expectation of a hotter climate is wrong. It simply draws attention to the fact that today’s climate experts predict a different and opposite trend to the experts of 30 years ago and makes us consider that the experts of 30 years ahead may in turn reverse the predictions of today’s experts. If today we were following the 1974 expert, we might be busy burning more fossil fuels in an effort to increase CO2 emissions and, therefore, stopping the climate getting colder.
As to the effects of CO2 as a possible agent of climatic change, the then encyclopaedia expert stated that ‘doubling or halving of the atmospheric CO2 would have only a small quantitative effect on planetary temperature.’
So there are two areas of difference between today’s climate experts and the experts of 1974. The first is that today’s experts believe there is a trend of climate change from cooling to warming and that this is not an oscillation but a one-way trend. The second difference is that today’s experts put the cause down to man-made CO2 emissions which were not regarded as significant in 1974.
In order to believe that there is now a trend to global warming and not a climatic oscillation and also to believe that the effects of CO2 build up are a major agent of global warming, it would be necessary to see a careful, believable and exact refutation of what was considered the conclusions based on best evidence thirty years ago. In other words, how was it the then experts got it wrong and why should we think the current experts are right?
To believe in the current orthodoxy on climate change we need to understand how the previous orthodoxy made a mistake.
ENCYCLOPAEDIA BRITANNICA 1974 (extracts)
“Temperatures fell markedly in each latitudinal band during the 1960s, just as they did during the late 1870s. Consequently, the temperature deviations since 1880 have been given with respect to the 1955-1959 mean.”
“The total picture is that of a first-order temperature fluctuation from a low about 1885 to a high in 1940, followed by a slight but accelerating reversal since that date. This trend from 1885 to 1940 is known as the ‘recent climatic fluctuation’.”
“It is estimated that mean surface water temperature rose 1.3o F (0.8o C) (1880-1940). This was most dramatic in high latitudes, where the Arctic pack ice retreated several hundred miles. Temperatures are now dropping once again as the pack ice readvances. Glaciers have behaved accordingly. The minor glacial advance of c.1890 was preceded by a decade of falling temperatures and unusally high precipitation; the subsequent retreat and thinning of ice sheets produced a ten centimetre (four inch) rise in world sea level. Glacier trends of the 1960s are uncertain; considering the time lag of previous advances, more universal glacier growth can be expected by the late 1970s.”
“In summary, the 75-year warm-up (1883-1940) was a planetary phenomenon that raised temperatures of the lower atmosphere by at least 1o F (0.6o C). The amplitude and duration of the negative trend developing since the 1940s suggests that a reversed first order fluctuations is currently under way. It is therefore unsurprising that the winter of 1962-63 in many parts of the Northern Hemisphere was one of the coldest in a century.”
“Instrumental records supplement other observations during the 200-year period 1670-1870, after which meteorological records become the primary criterion of climatic variation. During the past 100 years a worldwide first-order fluctuation has been discernible. A warm-up began in the mid 1880s and reached its climax about 1940; by 1955 temperature trends had generally been reversed, and during the 1960s there was a distinct cooling trend. The half-wave length of this “recent climatic fluctuation” has been just over 75 years, and its amplitude amounts to at least 1o F (0.6o C) for planetary air and surface-water temperatures.”
“The most probable cause of climatic variations would seem to be the Sun, which regulates the basic heat budget of Earth. Measurements of the solar constant and of certain variants within the solar spectrum have become available only in recent decades, and for total incoming radiation the apparent variability is only about as great as the possible margin of error.”
“Fluctuations of solar radiation provide fascinating but inconclusive possibilities for climatic changes. Other possibilities for modifications of radiation lie within the Earth’s atmosphere, where carbon dioxide (CO2), water vapour, ozone (O3), and pollutants such as volcanic dust operate as selective screens for short-wave (incoming) and long-wave (outgoing) energy. Each tends to absorb solar radiation, converting it to energy that is released in the lower atmosphere; at the same time cooling of the atmosphere is retarded. An increase of these components therefore favours higher planetary temperatures.”
“Because the underlying mechanisms of climatic variation are so imperfectly understood, it is difficult to predict future climatic trends other than on the basis of empirical experience. Seen from an immediate perspective, the cool-moist trend of the 1960s was of sufficient magnitude and universality to suggest that the next few decades will continue to be on the cool side in high latitudes and on the moist side in the tropics. Winters will more often than not be colder and snowier than average, and more summers will be either cool or wet. The minor readvance of mountain glaciers that this can be expected to produce by the late 1970s should actually be beneficial because summer meltwaters help maintain stream flow in semi-arid environments. Viewed on a broad time scale, the Holocene Epoch is but another interglacial of the Pleistocene Ice Age.”
“This can be inferred from the persistence of ice sheets in Antarctica and Greenland and of a frozen Arctic Ocean. Previous interglacials have been roughly 40,000 years long, so that another glacial is hardly imminent, at least not for another 20,000 years or so. One thermal maximum was passed some 6,000 years ago, but there is no reason why there should not be at least another hypsithermal or two before glaciers re-form over the areas of northern Canada and Scandinavia.”
FUTURUS/07 April 2007
The conclusion of the article is that:
“A warm up began in the mid 1880’s and reached its climax about 1940’s; by 1955 temperature trends had generally been reversed, and during the 1960’s there was a distinct cooling trend.”
and the forecast was:
“Winters will more often than not be colder and snowier than average, and more summers will be either cool or wet.”
The prognosis for climate as predicted by one of the best experts in the field in the mid 1970’s was therefore for a colder climate.
This does not mean that today’s climate experts’ expectation of a hotter climate is wrong. It simply draws attention to the fact that today’s climate experts predict a different and opposite trend to the experts of 30 years ago and makes us consider that the experts of 30 years ahead may in turn reverse the predictions of today’s experts. If today we were following the 1974 expert, we might be busy burning more fossil fuels in an effort to increase CO2 emissions and, therefore, stopping the climate getting colder.
As to the effects of CO2 as a possible agent of climatic change, the then encyclopaedia expert stated that ‘doubling or halving of the atmospheric CO2 would have only a small quantitative effect on planetary temperature.’
So there are two areas of difference between today’s climate experts and the experts of 1974. The first is that today’s experts believe there is a trend of climate change from cooling to warming and that this is not an oscillation but a one-way trend. The second difference is that today’s experts put the cause down to man-made CO2 emissions which were not regarded as significant in 1974.
In order to believe that there is now a trend to global warming and not a climatic oscillation and also to believe that the effects of CO2 build up are a major agent of global warming, it would be necessary to see a careful, believable and exact refutation of what was considered the conclusions based on best evidence thirty years ago. In other words, how was it the then experts got it wrong and why should we think the current experts are right?
To believe in the current orthodoxy on climate change we need to understand how the previous orthodoxy made a mistake.
ENCYCLOPAEDIA BRITANNICA 1974 (extracts)
“Temperatures fell markedly in each latitudinal band during the 1960s, just as they did during the late 1870s. Consequently, the temperature deviations since 1880 have been given with respect to the 1955-1959 mean.”
“The total picture is that of a first-order temperature fluctuation from a low about 1885 to a high in 1940, followed by a slight but accelerating reversal since that date. This trend from 1885 to 1940 is known as the ‘recent climatic fluctuation’.”
“It is estimated that mean surface water temperature rose 1.3o F (0.8o C) (1880-1940). This was most dramatic in high latitudes, where the Arctic pack ice retreated several hundred miles. Temperatures are now dropping once again as the pack ice readvances. Glaciers have behaved accordingly. The minor glacial advance of c.1890 was preceded by a decade of falling temperatures and unusally high precipitation; the subsequent retreat and thinning of ice sheets produced a ten centimetre (four inch) rise in world sea level. Glacier trends of the 1960s are uncertain; considering the time lag of previous advances, more universal glacier growth can be expected by the late 1970s.”
“In summary, the 75-year warm-up (1883-1940) was a planetary phenomenon that raised temperatures of the lower atmosphere by at least 1o F (0.6o C). The amplitude and duration of the negative trend developing since the 1940s suggests that a reversed first order fluctuations is currently under way. It is therefore unsurprising that the winter of 1962-63 in many parts of the Northern Hemisphere was one of the coldest in a century.”
“Instrumental records supplement other observations during the 200-year period 1670-1870, after which meteorological records become the primary criterion of climatic variation. During the past 100 years a worldwide first-order fluctuation has been discernible. A warm-up began in the mid 1880s and reached its climax about 1940; by 1955 temperature trends had generally been reversed, and during the 1960s there was a distinct cooling trend. The half-wave length of this “recent climatic fluctuation” has been just over 75 years, and its amplitude amounts to at least 1o F (0.6o C) for planetary air and surface-water temperatures.”
“The most probable cause of climatic variations would seem to be the Sun, which regulates the basic heat budget of Earth. Measurements of the solar constant and of certain variants within the solar spectrum have become available only in recent decades, and for total incoming radiation the apparent variability is only about as great as the possible margin of error.”
“Fluctuations of solar radiation provide fascinating but inconclusive possibilities for climatic changes. Other possibilities for modifications of radiation lie within the Earth’s atmosphere, where carbon dioxide (CO2), water vapour, ozone (O3), and pollutants such as volcanic dust operate as selective screens for short-wave (incoming) and long-wave (outgoing) energy. Each tends to absorb solar radiation, converting it to energy that is released in the lower atmosphere; at the same time cooling of the atmosphere is retarded. An increase of these components therefore favours higher planetary temperatures.”
“Because the underlying mechanisms of climatic variation are so imperfectly understood, it is difficult to predict future climatic trends other than on the basis of empirical experience. Seen from an immediate perspective, the cool-moist trend of the 1960s was of sufficient magnitude and universality to suggest that the next few decades will continue to be on the cool side in high latitudes and on the moist side in the tropics. Winters will more often than not be colder and snowier than average, and more summers will be either cool or wet. The minor readvance of mountain glaciers that this can be expected to produce by the late 1970s should actually be beneficial because summer meltwaters help maintain stream flow in semi-arid environments. Viewed on a broad time scale, the Holocene Epoch is but another interglacial of the Pleistocene Ice Age.”
“This can be inferred from the persistence of ice sheets in Antarctica and Greenland and of a frozen Arctic Ocean. Previous interglacials have been roughly 40,000 years long, so that another glacial is hardly imminent, at least not for another 20,000 years or so. One thermal maximum was passed some 6,000 years ago, but there is no reason why there should not be at least another hypsithermal or two before glaciers re-form over the areas of northern Canada and Scandinavia.”
FUTURUS/07 April 2007