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Hot Air on Cold Air

Lessons from the warming but confused citizenry from the failed 1970s predictions of global cooling

In the 1970s, climate scientists knew there was a link between CO2 and global warming, the cooling effects of sulphate aerosols in the atmosphere and even of Earth’s cyclic change of orbit around the sun, believed to be the precursor to the planet’s ice ages.

Between the 1940s and 1970s was a period of global cooling in the Northern Hemisphere; ground temperatures dropped, the polar caps appeared to be growing and weather patterns brought unseasonal amounts of snow and ice cover. In particular, satellite imagery revealed a sudden increase in Northern Hemisphere snow cover between 1971 and 1972.

As far back as 1938 an analysis of long-term warming trends from the 1870s had been published, demonstrating for the first time that temperature increase was linked to the onset of the industrial revolution and CO2 emissions. A survey of scientific literature from 1965 to 1979 found 7 articles predicting cooling and 44 predicting warming, but it was global cooling that made media headlines.

In the early 1970s, scientists debated why the Earth appeared to be cooling, and it was hypothesised that sulphate aerosols – which reflect sunlight – might be countering the warming effects of carbon dioxide. A small number of scientists posited the notion that the Earth might, in fact, be heading toward an ice age.

America and Europe had escaped the 500-year-long so-called ‘Little Ice Age’ around 1850, and it was feared there could be a worldwide return. Moreover, it had been discovered that the present interglacial age was in fact an anomaly in Earth’s history and that a new glacial age was due ‘soon’. How soon was open to wide debate.

Echoing these concerns, Professor Kenneth E.F. Watt, scientific and policy advisor to the Center for the Study of Carbon Dioxide, said in 1970: “If present trends continue, the world will be about four degrees colder for the global mean temperature in 1990, but 11 degrees colder by the year 2000. This is about twice what it would take to put us in an ice age”.

NASA too, was concerned, and in July 1971, NASA scientist S.I. Rasool predicted that if fossil-fuel dust continued to be injected into the atmosphere over several years, “such a temperature decrease could be sufficient to trigger an ice age”.

At a meeting of the National Academy of Sciences (NAS) in January 1974, certain scientists suggested the evacuation of six million people from the Sahel region in Africa. They feared faced starvation due to the effects of global cooling.

Well-meaning 1970s celebs got in on the act. Leonard Nimoy narrated the apocalyptic T.V. documentary, ‘In Search Of The Coming Ice Age’. In his authoritative Vulcan timbre, Nimoy intoned:

“Climate experts believe the next ice age is on its way…if we are unprepared for the next advance, the result could be hunger and death on a scale unprecedented in all of history…during the lifetime of our grandchildren, arctic cold and perpetual snow could turn most of the inhabitable portions of our planet into a polar desert”.

Predictably, the press seized on all these apocalyptic predictions and, ignoring 1970s scientific consensus, afforded credibility to the global cooling theorists as they revelled in the story’s sensationalist potential. Very soon, global cooling found new advocates as reporters fell behind the new narrative.

Even the reputable, ‘quality’ press foretold the end of civilisation: ‘New Ice Age Coming – It’s Already Getting Colder’ (L.A. Times, Oct 1971); ‘Scientist Sees Chilling Signs Of New Ice Age’ (L.A. Times, Sept 1972); ‘Science: Another Ice Age?’ (Time magazine, Nov 1972); ‘Ice Age, Worse Food Crisis Seen’ (The Chicago Tribune, Oct 1974); ‘The Cooling World’ (Newsweek, Apr 1975); ‘The Big Freeze’ (Time magazine, Jan 1977).

The New York Times, in particular, left impartiality and journalistic standards out in the cold. In the period from 1924 to 2005, The Times reported four climate changes, each one contradicting the last: ‘MacMillan Reports Signs of New Ice Age’ (Sept 1924); ‘America in Longest Warm Spell Since 1776…’ (Mar 1933); ‘Scientists Ponder Why World’s Climate is Changing; A Major Cooling Widely Considered to be Inevitable’ (May 1975); ‘Past Hot Times Hold Few Reasons to Relax About New Warming’ (Dec 2005).

It was these inconsistencies and the preference of sensationalism that obfuscated genuine debate and misinformed the general public, obscuring very real concerns over global warming. It could be argued that journalists were simply reporting what scientists were saying, but much of the information was misrepresented, only a minority of the scientific community were referenced or quoted, and conflicting scientific literature was not referred to. It was unbalanced, unscientific.

Campaigners inevitably picked up on the journalism. At the first Earth Day celebration in April 1970, environmentalist Nigel Calder warned “the threat of a new ice age must now stand alongside nuclear war as a likely source of wholesale death and misery for mankind”.

A number of ‘solutions’ were put forward to counter the cooling, including pumping extra CO2 into the atmosphere, diverting arctic rivers and even melting polar caps by covering them with black soot. However, climatologists – not implausibly – believed these measures would only create more problems than they would solve.

The impact of CO2 was never forgotten and some attempted to establish a sort of CO2/aerosol calculus. The opposing effects were weighted in a 1971 paper by Rasool and Dr Steven Schneider; the conclusion of this study was that an increase by a factor of four in global atmospheric aerosol could be enough to trigger another ice age. Critics noted that the effects of aerosols in the atmosphere had been overestimated in comparison to the warming effects of CO2.

In 1975, the NAS backtracked on its initial concerns, reporting: “Our knowledge of the mechanisms of climate change is at least as fragmentary as our data…Not only are the basic scientific questions largely unanswered, but in many cases we do not yet know enough to pose the key questions’. The heat was cooling.

By 1980, predictions of an imminent ice age had largely ceased, as scientists agreed it would take thousands of years before the next one occurred. Hot scientists welcomed their prodigally colleagues back into the heat.

However outliers subsisted and in 2004 – again in a gross misrepresentation of the facts – The New York Times quoted the 1972 NAS report as reading: “Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to an end, leading into the next glacial age”.

What the NAS report actually read was: ‘Judging from the record of the past interglacial ages, the present time of high temperatures should be drawing to and end, to be followed by a long period of considerably colder temperatures leading to the next glacial age some 20,000 years from now”.

In October 2006, Senior Editor of Newsweek Jerry Alder – whose publication had been one of the main promulgators of the ice- age myth – admitted that a report on global cooling in 1975 was “spectacularly wrong about the near-term future”, but went on to claim that even Isaac Asimov had concerns over climatic change and food production.

The conclusion drawn must be that there was indeed a significant drop in Northern Hemispheric temperature during the 1970s, that a minority of scientists favoured the view of overall global cooling, and that the press misrepresented scientific papers and failed in their duty to provided balanced, informed reporting.

Today, 97% of climate scientists believe that the Earth is warming, that it is largely driven by anthropogenic factors, and that the situation is dire. Few of the minority believe in global cooling. Scientists know that temperatures have risen since the onset of the Industrial Revolution, that CO2 and other gases are the main driving force, and that the fate of our planet now rests in our hands.

The technology we now have and knowledge we have accumulated were largely not available thirty years ago. Climate sceptics will point to the 1970s as ‘proof’ that climate change is a hoax, but will fail to acknowledge the facts as laid out by twenty-first-century science. The Earth is warming fast, and has been steadily warming since the mid 1800s when the industrial revolution began – of that there is no question.

The real question now is whether the public will trust the media to report the science. 

Written by Ken Phelan