A rough estimate of the number of scientists globally

I got to wondering about how many scientists there are in the world. Eleven thousand of them have declared a "climate emergency" recently. The trouble with numbers is that sometimes they don't really tell you anything. I'll probably get in trouble with all the mathematicians now for saying that.

It's hard to know the significance of 11,000 scientists unless one knows what percentage of all scientists that is.

However, the number of scientists in the world at any given moment is difficult to determine. The world seems to be getting more and more of them, although they seem to be accomplishing less and less.

It's a moving target. Even as I write this column, some scientists are being killed in lab explosions and some from infections contracted during experiments. It's a risky career! Others are being murdered by angry spouses, both their own and others. Still others are being promoted out of science into administration. These seldom recover. Then there are the retired scientists. No one quite knows what to do with them ...

Many are young children, even at this moment, considering becoming scientists. Occasionally they even have encouragement from their parents. That's serious child abuse. Still there are others for whom it is too late as they are already actively pursuing careers as scientists. Every year sees a new crop of scientists graduating into the ranks of researchers.

And, if you ask the scientists themselves, you will find there is little agreement about who a scientist is.

Most of us think we are scientists but harbor serious reservations about all the rest. For example, what are engineers? Are they lower-level technologists? What are academics? Are they just teachers of known facts? Both are valuable, but are they scientists?

Anyway, I decided to see if I could estimate the number of scientists in the world by making some rough estimates; sort of a rough back-of-the envelope calculation, although rougher, and without the envelope. For example, there are about eight billion people in the world. About 7% have college degrees, according to Google.

If we assume all scientists have college degrees that would be about 560 million possible scientists.

But only about 20% have degrees in Science, Technology, Engineering, or Math (STEM) which cuts the number down to 112 million. However, only about 20% of those go into "scientific" positions or careers. So now we are down to about 22 million.

The truth is that most practicing scientists today have more than a bachelor's degree; and the number of people with further education reduces the possible number of scientists by at least another 10%, possibly more.

That means we could easily be down below 20 million.

Google says that in 2013 there were about 80 million full-time-equivalent researchers in the world.

I think they are confusing technicians and academics with scientists. Science is a process of logical inquiry in which philosophers use the rules of science to try to falsify their own conclusions.

That means many people with STEM backgrounds are probably not "scientists." But that does not mean their contributions are not essential or important.

My estimate, and Google's, are far apart. I suppose we could average the two, but I'm not sure we should assume averages are any form of truth.

Personally, I think my approximations are better than Google's because I am a scientist, and they are just technical experts.

But let's not to lose sight of the reason for doing this whole exercise: 11,000 scientists claiming a climate emergency represents less than 1% of the estimated number of scientists in the world.

11,000 ÷ 20,000,000 = 0.00055 x 100 = 0.055%

Even if I am off by 50%, 11,000 is still only about 1% of the scientific population. If there are only five million scientists, 11,000 is barely 2% of all scientists who are worried about climate change.

I wonder what the rest of us think.

Gary McCallister, gmccallister@bresnan.net, is a professor emeritus of biological sciences at Colorado Mesa University.

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