Most climate change impacts are subtle and observable, while the remaining few are more abrupt and challenging to predict. These unanticipated events can be abrupt and cannot be easily beaten at the last moment. So is the idea of global cooling for many believers! Misgivings and unfounded misrepresentation have sunk so bad that NASA felt compelled to publicly clarify one of the most popular urban myths. What was the myth of the 1970s? 

A possibility of Global cooling
A possibility of Global cooling | Image Credit – Vince Gx

Well, people believed that a decrease in the sun’s output would soon cause cooling and a mini-ice age! And we don’t understand why the believers never considered the volume of greenhouse emissions impacting ozone depletion in this fraction. According to research, human-caused global warming has wiped away the fundamental global cooling that transpired over the preceding 6,500 years over the last 150 years.

These evolving temperatures have been ascertained by differences in Earth’s orbital path over hundreds of years. While longer distances have contributed to colder periods, closer transitions to the sun have contributed to warmer, interglacial periods. But are historical patterns enough to say that we are heading towards global cooling in the future?

The Tilt of Earth’s Rotational Axis Inducing Ice Age

The Tilt of Earth's Rotational Axis
The Tilt of Earth’s Rotational Axis | Image Credit – Wikimedia Commons

When people imagine Ice Ages, they often envision a long-term delayed shift into a northern hemisphere climate. Evidently, analyses of the past million years of planetary science show a repetitive cycle of Earth’s climate transitioning from warm interglacial periods to glacial environments. The timespan of these transitions is linked to differences in the lean of Earth’s rotational axis, shifts in the alignment of Earth’s elliptical orbit around the sun, known as the precession of the equinoxes, and changes in the shape of the elliptical orbit.

The supposition that orbital shifts induced the waxing and waning of ice ages was first proposed by James Croll in the nineteenth century and expanded upon by Milutin Milankovitch in 1938. Even though the Ice Age cycle is global in scope and emerges in sequence in both hemispheres, ice age constraints typically happen when all of those, as mentioned above, collude to establish a minimal level of summer sunlight on the arctic regions of the Earth. 

It significantly impacts ice dispersion over land and sea, atmospheric temperatures and circulation, and ocean temperatures and circulation at the surface and large depths. So why would we worry about the end of the current interglacial and the slow shift to the next Ice Age, which could be several millennia apart (that is, if the claims were valid!)? In fact, won’t the accumulation of carbon dioxide and other greenhouse gases help mitigate potential developments of the global cooling effect?

In the 1970s, scientists warned about a coming ice age: myth or fact?

If you were up and alive in the 1970s, you might recall a multitude of problematic newspaper sensationalist warnings of an impending ice age. However, a closer look reveals that those publications were premised on a small collection of documents in the scientific minority.

A few science articles explored the prospect of a new ice age in the future, which sparked some theatrical media exposure backed up by science. A 1971 paper by Stephen Schneider, then a climate researcher at NASA’s Goddard Space Flight Center in Maryland, US, may have been a starting point for this assumption. 

Schneider’s paper proposed that if aerosol pollution quadrupled, the cooling effect of contaminated air could vastly exceed the greenhouse effect of carbon dioxide, likely contributing to an ice age. A publication published in the journal Nature Geoscience reaffirms that a fall in carbon dioxide approximately 34 million years ago exacerbated Earth to obtain an icehouse state, an era of global cooling. 

Throughout this period, recognized as the Eocene Oligocene transition, the global average temperature fell by more than 5.4 degrees Fahrenheit (3 degrees Celsius) in about 300,000 years. This geologically rapid change demonstrates how atmospheric carbon dioxide inspires major climate shifts. Moreover, marine geologic records indicate that Earth was in a warm greenhouse state prior to 34 million years ago. On any landmass, there were no ice sheets or glaciers. And then there was a sharp drop in temperature. 

All of this current information is derived primarily from marine sedimentary specimens. However, there was less indication of how the ancient evolution occurred on land because it was difficult to locate a record in decent shape. Previously, experts were baffled as to why the Eocene Oligocene transition occurred.

They assumed it was due to a shift in the Antarctic ocean’s currents for some time. However, that theory progressively fell out of fashion. Later, the scientists determined that only a reduction in carbon dioxide could have caused a significant decrease in temperature in the geologically small time frame of 300,000 years. 

The data corroborate that carbon dioxide is a major contributor to climate change. The models used, established by the Bristol Research Initiative for the Dynamic Global Environment, also accurately represented past climate change, making them helpful in forecasting future climate change. Climate science was in its babyhood in the mid-twentieth century, with scientists only beginning to decode the implication of competitive forces governing climate.

The Controversy: NASA’s Goddard Institute for Space Studies (GISS) Surface Temperature Analysis (GISTEMP)

NASA's Goddard Institute for Space Studies
NASA’s Goddard Institute for Space Studies | Image Credit – Flickr

Despite multiple rows of merging empirical proof proving that our globe is warming, headlines and articles in media occasionally call this a conundrum. New research is perceived as rebutting prior findings or analyzing advanced data to refute previously proven scientific thoughts and ideas. Several news sources and internet sites, for instance, covered a story a few years back that examined data from NASA’s Goddard Institute for Space Studies (GISS) Surface Temperature Analysis (GISTEMP), which forecasts a shift in the global surface temperature. 

The paper mentioned a short-term cooling trend that appeared in the dataset in 2017 and 2018 and asserted accurately that short-term cooling iterations, as demonstrated in the paper, are statistical noise compared to the long-term trend. The narrative also exemplified why fixating on a short period of time, for instance, one, two, or perhaps several years, does not reveal what is really passing on with long-term developments. In fact, it is very plausible to be deceptive. So, what is the most important thing to understand about studying global temperature dynamics?

To start, it is critical to comprehend that global surface temperatures are a noisy signal, which means they are constantly fluctuating to some extent due to repeated interplay between the various constituents of our complicated Earth system (e.g., land, sea, air, ice).

The interaction of these constituents drives our weather and climate. As a result, acknowledging global temperature trends necessitates a long-term standpoint. Scientists are becoming more confident that estimations of the Earth’s long-term temperature increase in recent decades are precise and unquestionable.

Who Were these Scientists Anticipating Cooling?

Earth in Global Cooling
Earth in Global Cooling | Image Credit – Wikimedia Commons

Countless people assume that in the 1970s, all scientists theorized that the Earth was cooling. A factual inspection of the contentious report confirms an agreement between many experts. But, the common understanding today is that they were not well equipped with the tools and technologies for accurate climate forecasts. 

Don Easterbrook, Syun Akasofu, Habibullo Abdussamatov, Joe D’Aleo, and Nicola Scafetta are among the names on the directories of scientists forecasting global cooling. Several of these and other identities on these directories are not climatologists, which is why the statements state that a steadily rising number of scientists opposed previous scientists anticipating imminent cooling.

One must ponder how long the Earth can persist warming while these people predict imminent cooling before their legitimacy is eroded. Don Easterbrook, for instance, has projected that a switch in the Pacific Decadal Oscillation will result in a global cooling of 2 to 5°F (1.1 to 2.8°C) from 2000 to 2030. We are now one-third of the direction through this ostensibly cooling period, but the Earth has warmed by about a global mean of 0.1°C. And thus, this prediction’s precision is definitely not promising.

Scafetta, Abdussamatov, Landscheidt, Archibald, and D’Aleo, among others, have projected that global cooling due to solar effects will occur. Notwithstanding this, however, the most extended solar cycle’s minimum threshold in nearly a Century has just ended. As previously stated, the last two years have been among the hottest in the instrumental temperature record.

To Conclude

According to current opinion pieces, many scientists and science news are still alerting of an impending global cooling, with some even going above and beyond to deem it a growing consensus. These website contents have two serious shortcomings: first, there is no scientific justification for assertions that the Earth will begin to cool in the coming years, and second, many climate scientists do not foresee global cooling at all.

In light of mind-boggling evidence that the anthropogenic warming output due to fossil fuels is pushing the long-term temperature pattern, it is difficult to comprehend that any scientists would indicate that this tendency will abruptly counteract amidst ever-increasing human greenhouse gas emissions.

With all of this substantiation indicating that human activity is primarily responsible for rapid global warming with no signs of slowing down, one must speculate how any scientist (or an individual!) would suddenly forecast looming global cooling. The question is no longer whether global cooling in the future is possible, but how bad is global warming going to be?

Shradha Bhatta holds a Bachelors’s Degree in Social Work along with a Post-graduate degree in Project Management from Georgian College in Canada. Shradha enjoys writing on a variety of topics and takes pleasure in discovering new ideas. She likes traveling and spending time with nature. She is a very people-person who loves talking about climate change and alerting people to go green!