In 1974, CO2 level was 350ppm, the safe level, why were scientists worried about an ice age occurring?

Technically we ARE in an ice age RIGHT NOW, but it is an interglacial period. During the Dalton minimum roughlyb200/years ago, that was almost a micro ice age not quite a deep as the Little Ice age during the Maunder minimum. Greenland really was green when the Norse colonized it.

In 1974 we were going into a solar minimum activity period. Many scientists thought that might trigger another very small ice age.

Right Noe we probably ate going into another long period of minimum solar activity, That's kind of ironic and contradictory and seemingly illogical.

They hadn't fully integrated l and correlated the Milankovitch cycles caused by the changes in the eccentricity of Earth's orbit with ice core temperature data. Partly it was lack of computing power and data crunching that we can now do at a much faster rate.

After reading the other answers, the CFCs in the atmosphere from .aerosols was one of the reasons. You could often see a layer if air pollution along the western

This is typically revised history from a science illiterate.

The issue was dust in the atmosphere - noted but downplayed by scientists yet played up by a sensationalist press and ignorant readers.

Not sure where you source the level of Co2 in 74 (you don’t provide one) as an actual source the level was in fact 330

https://www.e-education.psu.edu/earth103/node/1018

As for the talk of most scientists predicting an ice age, that’s a denier myth, some scientists suggested it, but many other even then where talking about warming due to rising Co2, and the temp data over the following 50 years now support that even more strongly.

https://skepticalscience.com/ice-age-predictions-i...

The scientific papers published at the time exist in many databases, deniers don’t look because they fear anything that effects the myths they have created.

The National Academy of Science looked into this in 1979, concluding warming was the issue.

https://books.google.com.au/books?id=cj0rAAAAYAAJ&...

It's easy to find if you know how to use Google. Massive amounts of aerosols were blocking out sunlight and sulfur dioxide causes cooling too.

How was that determined to be safe by pulling numbers out of a hat?

The history of the modern “Climate Change” scam.

In January 1972, the National Science Foundation held a meeting at Brown University to discuss “climatic change” – which meant global cooling, which they said was of natural origin.

Later that year, the participants sent a letter to President Nixon warning of a new ice age within a century.

The White House “seized” on the global cooling threat.

NASA’s top climate experts predicted a new ice age by the year 2021.

The US Military responded to the global cooling, which they said was causing “extreme weather”

Everything which now gets blamed on global warming, was blamed on global cooling.

Scientists realized that global cooling was a potential big money scam for them.

In 1974, the New York Times reported on a meeting of climate experts in Germany. There was unanimous consensus that global cooling threatened the world’s food supply. Walter Orr Roberts of NCAR was a key player behind this.

In 1974, the CIA said global cooling would produce drought, famine, international conflict and political unrest throughout the world.

The White House bought off on the global cooling/climate change scam, and by December, 1974 taxpayer dollars were permanently diverted (extorted) by the scientists. By the early 1980’s, the global cooling scam had seamlessly morphed into the global warming scam.

The climate mafia now denies the global cooling scam ever happened, saying it consisted of “nine paragraphs in Newsweek in 1975.” Climate criminals assume that everyone else is stupid and will believe anything they say.

There is nothing new about this however. Scientists have been pulling the same climate change scam for centuries.

The notion that renewable energies and batteries alone will provide all needed energy is fantastical. It is also a grotesque idea, because of the staggering environmental pollution from mining and material disposal, if all energy was derived from renewables and batteries. Worse, tricking the public to accept the fantasy of 100 percent renewables means that, in reality, fossil fuels reign and climate change grows.

James Hansen June, 2018

Life thrived on Earth with CO2 at 10-20X current levels. Your concerns are not based on science.

scientists were NOT worried about an ice age in the 70's. This was all overhype of some cooling by the media.

This a good question and after reading your reference I have to laugh. Plants stop growing at 150ppm and are struggling at 250ppm. Back in 1974 they had long cold winters, crop shortages and famines. This is just before things started to warm up in the 80s, so it had to be a cool solar cycle for their concerns.

I have always focused on increasing levels, not the other way. I am going to look into this further.

Aerosols. We fixed it. Now it’s CO2. We’re not fixing it.