Today a hot scientific headline is the global competition rushing to make fusion power plants possible. Several scientific groups have optimistically predicted that they would soon make breakthroughs in achieving net power output with their fusion power generators. But they seem to have chosen to ignore that fusion is the process of producing helium and helium in nature is an extremely stable existence and thus will not disappear through either natural or artificial processes. In the meantime, the might of industrialization would potentially increase the concentration of helium far beyond its current level. As an asphyxiant gas, despite its current harmless status in nature, the accumulative effect of diluting oxygen and nitrogen in earth atmosphere in large quantity could be severely pernicious decades later if it happens at a fast pace. Therefore, the mass production of helium through the fusion industry could potentially suffocate the earth with supernumerary helium in the atmosphere.
Historical experience has shown time and again that when it comes to the issue of damaging the earth's environment, the scientists of this world have often been swift in doing it but slow in regretting the consequence. This is a sad fact in the history of industrialization when it is supposed to (and does) benefit the mankind.
A few centuries ago, when the first industrial revolution began, scientists had no idea at all that carbon dioxide, a trace gas in the atmosphere, would one day be the subject of worldwide emissions control. But now when the world is crying out about too much carbon dioxides in the atmosphere, scientists once again are working very hard by spending billions of dollars in something that could potentially be the preparation for another round of future air pollution, a possibly much worse kind of pollution than the carbon dioxides, without seemingly aware of it.
Today a hot scientific headline is the global competition rushing to make fusion power plants possible. Several scientific groups have optimistically predicted that they would make some breakthrough in achieving net power output with their fusion power generators.
However, it is well known that the process of fusion power generation is turning deuterium from the ocean to helium in the atmosphere [
While scientists are claiming that helium is a harmless clean gas they seem to have forgotten also to tell us the following facts about it:
As an inert gas, helium molecules are essentially impossible to be eliminated from our earth environment once they are generated. Compared with carbon dioxide, helium is not only too light and too tiny to be comfortably collected, but also too inert to be absorbed through chemical means; accordingly, there is no natural process in Earth's nature that would convert helium into a gas as beneficial to human health as photosynthesis does for carbon dioxide.
2. Confusion about the potential hazardous role of helium
Helium has been a harmless trace gas in the atmosphere of earth, and accordingly there have been much confusion about the potential hazardous role of helium to human civilization in case its concentration in the atmosphere increases tremendously.
2.1. Confusion due to the contrast to chemically active toxic pollutants
The inertness of helium and its tiny concentration in the atmosphere may lead to the illusion that helium is always a harmless or even benign existence compared to harmful chemically active pollutants. However, the very inertness makes it impossible to be disintegrated like other pollutants once it is produced in the earth environment, which makes any industrial production of helium is irreversible, neither through artificial approaches nor through natural approaches.
While currently the whole world is worrying about heavy productions of carbon and nitrogen oxides as the most unwanted environmental nuisances produced by human activities or even excrement of livestock, we should feel fortunate that nature could digest most of those pollutants to largely restrain their growths in the atmosphere. Without the natural circulations of the carbon and nitrogen elements from pollutants to nutritious ingredients, we would have seen magnitudes higher of the concentrations of those pollutants in the atmosphere. However, with helium we do not have the much needed natural circulation, and consequently, all the helium gases produced as the industrial products would be accumulated in the atmosphere, and we should expect a much higher acceleration rate of the increase of concentration of helium in the atmosphere once it is produced through industrialized processes.
As an asphyxiant gas, despite its current harmless status in nature, the accumulative effect of diluting oxygen and nitrogen in the earth atmosphere in large quantity could be severely pernicious decades later if it happens at a fast pace.
Therefore, the most worrisome aspect of turning the deuterium of our seawaters into helium in the atmosphere is that the process is basically irreversible, that is to say the end products are accumulated monotonically. With this natural logic, the dilution of oxygen and nitrogen concentrations in the atmosphere by helium could be negligible if the concentration of helium grows at a negligible pace, or threatening if the concentration of helium grows at a threatening pace.
2.2. Confusion due to ignorance of industrial might and Jevons paradox
Although currently the normal concentration of helium in our atmosphere is only 5ppm, and scientists claim that only a very small amount of deuterium will be used at any moment for the fusion reaction, they seem to forget that the might of global industrial mass production is not what the experimental scale in their labs can match at all. Besides, they seem also to forget the famous Jevons paradox [[2]] which tells that industrial production itself would greatly beef up the desire of consuming the products and thus further greatly boost the production.
The abovementioned irreversibility of the production of helium or the accumulation of the concentration of helium in the atmosphere would quickly become dangerous once the production is at the global industrialized level.
Given the impossibility of eliminating helium from our earth environment, in case decades from now we find out that the atmosphere is filled with helium pollution as the result of the scientific community's obsession today of the advanced technology and their own fame, it will not be as easy to fix as reducing carbon emissions today, and the outcome would be catastrophic to Homo sapiens.
2.3. Confusion due to the light weight of helium
When talking about the potential harm caused by helium once it is mass produced through industrial manufacturing, people often use helium balloon as the example to show that helium would only exist at the outer boundary of the atmosphere waiting for the chance to escape from the grasp of earth gravity.
This is a double confusion. It first confuses helium gas with helium balloons and then it confuses the apparent relative abundance of helium at high altitudes with the lack of gravitational attraction.
First, why helium balloon would float up is due to the fact that the balloon as a whole is lighter than the surrounding air, but once the helium leaks out of the balloon it will permeate all over the atmosphere;
Second, the myth that light object is not attracted by gravity as much as heavy object was debunked by Galileo centuries ago. More specifically, if we drop a feather and a ball of lead in a vacuum chamber from the same height at the same time, we should expect that they would hit the ground at the same time; similarly, if we drop a helium molecule and a lead molecule in a vacuum chamber from the same height and at the same time, in the classical context (i.e. without considering the uncertainty issue assumed in quantum mechanics) we should expect that they would hit the ground at the same time.
In fact, if we inject a volume of helium gas in to a vacuum bottle, then we should expect that it will fill the whole bottle with the density a little higher at the bottom than at the top. We will never have the situation that all helium molecules are suspended in an agglomeration at the top as the analogy of helium balloon might lead people to imagine.
The reason why we could see relatively higher percentage of helium at high altitudes of the atmosphere is because during random intermolecular collisions in the atmosphere, the light weighted helium molecules tend to get greater velocities and bounce farther away (in any direction) than other heavy weighted molecules.
On the other hand, the very fact that helium tends to be more equally distributed across the whole depth of atmosphere would greatly increase the difficulty for humans to collect it or even put it under control.
2.4. Confusion about atmospheric escape
The so-called atmospheric escape of helium refers to the loss of helium at the far end of earth atmosphere, where the atmosphere gradually merges into the empty outer space and gas molecules could occasionally acquire large enough velocities that fall into the long tail of the Maxwell distribution [[3]]. When the velocity of a gas molecule occasionally gets so big to go beyond the escape velocity of earth gravity, that molecule could permanently escape the gravity of earth. While there are a few mechanisms for gases including helium to escape in general, the main mechanism causing helium molecules at the far end of earth atmosphere to escape from the gravity of earth is polar wind escape (e.g. [[4]]).
The reading of the atmospheric escape from the scientific literature has often caused some whimsical speculation that the helium on earth could easily escape from earth gravity. However, based on the known knowledge [[5]], even with the current minute amount of helium on earth, it could take another 150 billion years (more than 10 times of the current known history of our whole four dimensional universe) for all the helium of earth to escape at the known speed of escaping. In fact, all atmospheric escapes happen at small scales and polar wind escape depends on the amount of ions available at the pole, while the generation of ions gets more difficult as the ionization potential of the gas increases and helium has the highest ionization potential among all gases [[6]].
Most importantly, none of the existing known mechanisms that could potentially cause any gas molecules (not only helium) in the exosphere to escape the earth gravity is controllable. That is to say, in case the concentration of helium in earth atmosphere becomes catastrophically high due to its industrial mass production, humans have no way at all to artificially trigger any dreamed mechanism for helium to escape from the atmosphere.
3. Final Remarks
Unlike carbon, hydrogen, nitrogen, and oxygen elements in the existing major air pollutants, helium does not belong to the biology of life and thus an overloaded existence of helium on earth would not benefit the survival conditions for humans and other organic lives on earth in any sense. A jump of the concentration of helium in the atmosphere could dilute the concentrations of oxygen and nitrogen that are needed for human biological wellbeing as well as the biological wellbeing of plantations and animals, which means that it could suffocate the earth planet once for all. Unlike video games that many nowadays humans are obsessed with, mass production of helium through industrialized processes would be a game that cannot be replayed.
Besides, once the percentage of helium gets to a degree that is threatening to human health, no one can reduce the amount the inhaled helium. Masks that have helped humans to battle contagious diseases and air pollutions in the past would not work at all because the size of helium is tinier than the needed oxygen.
The irreversibility of the production of helium through the industrial might and the utter absence of means to reduce the concentration of helium in the atmosphere could make the breakthrough of mass productions of helium through industrialized fusion processes that nowadays scientists are dreaming of the beginning of the real doomsday of human civilization.
“….when the public embraces those achievements of science and technology as miracles and longs for the coming of the next ones, people often ignore one sad fact that as the ancient dreams come true, their potential negative social impacts could also become true.”
[[5]] Swiss National Science Foundation (2022). Leaking atmospheres seal the fate of planets. Retrieved from: https://www.snf.ch/en/2QLt6mvuU4hZj1yx/news/leaking-atmospheres-seal-the-fate-of-planets
[[6]] Dutton, J., Llewellyn-Jones, F. & Rees, D. Ionization Coefficients in Helium at High Pressures. Nature 200, 58–59 (1963). Retrieved from https://doi.org/10.1038/200058a0
