The Myth of Global Cooling

[James Brown]

Some guy on the internet wrote:

Not everyone agrees with climate change...In the 1970's the scientists warned us about spooky global cooling. It was gonna be another ice age by the year 2000. When that didn't happen, they said "oh now it's warming! It's getting too hot!"

This intrigued me. He led with, "Not everyone agrees" implying healthy debate, which is normal for scientific progress...up to a point. Not everyone agrees that the Earth is a sphere, either, but we don't let that "debate" prevent us from using our GPS devices.

Then he follows with, "In the 1970's the scientists warned us." This implies that there may be debate today about climate change, but in the 1970s, climate scientists (or maybe all scientists in every field) were a monolithic block, all united without a hint of dissent in "global cooling." This is a hallmark of simplistic, monolithic, binary thinking, of the desire to separate Us vs Them. "[ALL] the scientists...THEY warned us...THEY said."

Of course, that was not true in the 1970s anymore than some guy on the internet believes it to be true today. There was discussion about the possibility of global cooling four decades ago, but it was by no means on the same scale or the same degree with which climate change is discussed--and accepted--today.


"What 1970s science said about global cooling"

So in fact, the large majority of climate research in the 1970s predicted the Earth would warm as a consequence of CO2. Rather than climate science predicting cooling, the opposite is the case.

"How the "Global Cooling" Story Came to Be"

Nine paragraphs written for Newsweek in 1975 continue to trump 40 years of climate science. It is a record that has its author amazed...

But earth's glacial rhythms are "being overridden by human activities, especially burning fossil fuels," McCaffrey noted. The stories about global cooling "are convenient for people to trot out and wave around," he said, but they miss the point:

"What's clear is we are a force of nature. Human activity – the burning of fossil fuels and land change – is having a massive influence. We are in the midst of this giant geoengineering experiment."

"The Myth of the 1970s Global Cooling Scientific Consensus"

A review of the climate science literature from 1965 to 1979 shows the myth to be false. The myth’s basis lies in a selective misreading of the texts both by some members of the media at the time and by some observers today. In fact, emphasis on greenhouse warming dominated the scientific literature even then.

 Global_cooling

Global cooling was a conjecture during the 1970s of imminent cooling of the Earth's surface and atmosphere culminating in a period of extensive glaciation. Press reports at the time did not accurately reflect the scientific literature.[1] The current scientific opinion on climate change is that the Earth underwent global warming throughout the 20th century and continues to warm.[2]

The great global cooling myth

Looking at every paper that dealt with climate change projections or an aspect of climate forcing from 1965 to 1979, [researchers] were able to assess the ‘trends’ in the literature. They found that only 7 of the 71 total papers surveyed predicted global cooling. The vast majority (44) actually predicted that rising atmospheric carbon dioxide could lead to global warming...

Of course, there was a small group of scientists in a new field pointing to the inevitability of the coming ice age – the newly minted palaeoclimatologists. However, as Peterson and colleagues point out, they were speaking on timescales of tens of thousands of years...

The global cooling myth

From the point of view of todays science, and with extra data available:

1. The cooling trend from the 40’s to the 70’s now looks more like a slight interruption of an upward trend.

2. Sulphate aerosols have not increased as much as once feared (partly through efforts to combat acid rain); CO2 forcing is greater.

3. Interpretations of future changes in the Earth’s orbit have changed somewhat. It now seems likely (Loutre and Berger, Climatic Change, 46: (1-2) 61-90 2000) that the current interglacial, based purely on natural forcing, would last for an exceptionally long time: perhaps 50,000 years.

Of course, none of this will change the mind of some guy on the internet, nor give him pause from bringing it up the next time he thinks it will be convenient. But I wanted to leave it here for future reference.