Flashback NOAA 1974: ‘Extreme weather events blamed on global cooling’
In the 1970s, extreme weather events were blamed on global cooling
Interestingly, in the 1970s it was common for severe weather anomalies (for example, the deadly catastrophic drought plodding throughout the continent of Africa) to be linked to the global cooling occurring at that time. In 1974, NOAA acknowledged that many climate scientists had linked the drought and other extreme weather anomalies to the -0.5°C drop in temperatures that had occurred from the 1940s to 1970s.
“In the Sahelian zone of Africa south of the Sahara, the countries of Chad, The Gambia, Mali, Mauritania, Niger, Senegal, and Upper Volta are enduring a drought that in some areas has been going on for more than six years now, following some 40 previous years of abundant monsoon rainfall. And the drought is spreading—eastward into Ehtiopia and southward into Dahomey, Egypt, Guinea, Kenya, Nigeria, Somalia, Tanzania, and Zaire. … Many climatologists have associated this drought and other recent weather anomalies with a global cooling trend and changes in atmospheric circulation which, if prolonged, pose serious threats to major food-producing regions of the world. … Annual average temperatures over the Northern Hemisphere increased rather dramatically from about 1890 through 1940, but have been falling ever since. The total change has averaged about one-half degree Centigrade, with the greatest cooling in higher latitudes. A drop of only one or two degrees Centigrade in the annual average temperature at higher latitudes can shorten the growing season so that some crops have to be abandoned. … [T]he average growing season in England is already two weeks shorter than it was before 1950. Since the late 1950’s, Iceland’s hay crop yield has dropped about 25 percent, while pack ice in waters around Iceland and Greenland ports is becoming the hazard to navigation it was during the 17th and 18th centuries. … Some climatologists think that if the current cooling trend continues, drought will occur more frequently in India—indeed, through much of Asia, the world’s hungriest continent. … Some climatologists think that the present cooling trend may be the start of a slide into another period of major glaciation, popularly called an “ice age.”
But, like now, there were still a collection of scientists willing to reconsider the common-knowledge “beliefs” of the time. For example, Boer and Higuchi (1980) investigated the “belief” that more extreme climate variability accrued as temperatures cooled, concluding that the climate had not undergone significantly more extreme shifts in weather patterns and events during the mid-20th century global cooling period.
“In recent years there has been increasing concern about climatic change and variability and its influence on man and his activities. This concern has been formally expressed in a WMO statement on climate change and variability (WMO, 1976). Many studies concerning climate change have been undertaken. Most studies have concentrated on long-term trends in temperature. … There appears to be a general belief that the climate has become more “variable” in recent times. For instance, there is the suggestion that “since the 1940’s and 1950’s . . . the atmospheric circulation in the Northern Hemisphere appears to have shifted in a manner suggestive of an increasing amplitude of the planetary waves and of greater extremes of weather conditions in many areas of the world” (GARP, 1975, p. 16). … The results of this study do not support the contention that the climate has become significantly more variable, nor do they support a connection between variability and either mean temperature or north-south variation of temperature.”