Could the decline of atmospheric oxygen threaten human survival?
By Peter Tatchell
The Guardian – Comment Is Free – 13 August 2008
The rise in carbon dioxide emissions is big news. It is prompting action to reverse global warming. But little or no attention is being paid to the long-term fall in oxygen concentrations and its knock-on effects.
Compared to prehistoric times, the level of oxygen in the earth’s atmosphere has declined by over a third and in polluted cities the decline may be more than 50 percent. This change in the biochemistry of the air we breathe has potentially serious implications for our health. Indeed, it could ultimately threaten the survival of human life on earth, according to Roddy Newman, who is drafting a new book, The Oxygen Crisis.
I am not a scientist, but this seems a reasonable concern. It is a possibility we should examine and assess. So, what’s the evidence?
Around 10,000 years ago, the planet’s forest cover was at least twice what it is today, which means that forests are now emitting only half the amount of oxygen. Desertification and deforestation are rapidly accelerating this long-term loss of vegetative oxygen sources.
The story at sea is much the same. Nasa reports that in the North Pacific ocean oxygen-producing phytoplankton concentrations are 30 percent lower today, compared to the 1980s. This is a huge diminution in just three decades.
Moreover, the UN Environment Programme confirmed in 2004 that there were nearly 150 “dead zones” in the world’s oceans where discharged sewage and industrial waste, farm fertiliser run-off and other pollutants have reduced oxygen levels to such an extent that most sea creatures can no longer live there.
This oxygen starvation is reducing fish stocks and diminishing the food supplies of populations who are dependent on fishing. It also causes genetic mutations and hormonal changes that can affect the reproductive capacity of sea life, which could further diminish global fish supplies.
In prehistoric times, the oxygen levels were even greater. Robert Sloan’s article, “Plate Techtonics and the Radiations/Extinctions of Dinosaurs, the Pele Hypothesis,” lists the percentage of oxygen trapped in air bubbles in samples of dinosaur-era amber as: 28% (130 million years ago – mya), 29% (115 mya), 35% (95 mya), 33% (88 mya), 35% (75 mya), 35% (70 mya), 35% (68 mya), 31% (65.2 mya), and 29% (65 mya).
Professor Ian Plimer of Adelaide University and Professor Jon Harrison of the University of Arizona concur. Like most other scientists they accept that oxygen levels in the atmosphere in prehistoric times averaged around
30% to 35%, compared to only 21% today – and that the levels are probably even less in densely populated, polluted city centres and industrial complexes, perhaps only 15 % or lower.
Much of this recent, accelerated oxygen loss is down to human activity, notably the industrial revolution and the burning of fossil fuels. The Professor of Geological Sciences at Notre Dame University in Indiana, Keith Rigby Jr, was quoted in 1993-1994:
“In the 20th Century, humanity has pumped increasing amounts of carbon dioxide into the atmosphere by burning the carbon stored in coal, petroleum and natural gas. In the process, we’ve also been consuming oxygen and destroying plant life – cutting down forests at an alarming rate and thereby short-circuiting the cycle’s natural rebound. We’re artificially slowing down one process and speeding up another, forcing a change in the atmosphere.”
Very interesting. But does this decline in oxygen matter? Are there any practical consequences that we ought to be concerned about? What is the effect of lesser oxygen levels on the human body? Does it disrupt and impair our immune systems and therefore make us more prone to cancer and degenerative diseases?
Surprisingly, no significant research has been done, perhaps on the following not presumption: the decline in oxygen levels has taken place over millions of years of our planet’s existence. The changes during the shorter period of human life have also been slow and incremental – until the last two centuries of rapid urbanisation and industrialisation. Surely, this mostly gradualist decline has allowed the human body to evolve and adapt to lesser concentrations of oxygen? May be – or may be not.
The pace of oxygen loss is likely to have speeded up massively in the last three decades, with the fast-track industrialisation of China, India, South Korea and assorted other countries, and as a consequence of the massive worldwide increase in the burning of fossil fuels.
In the view of Professor Ervin Laszlo, the drop in atmospheric oxygen has potentially serious consequences. A UN advisor who has been a Professor of Philosophy, Systems Sciences, and Future Sciences at five American universities, Laszlo writes in his book, Macroshift: Navigating the Transformation to a Sustainable World (2001):
“Evidence from prehistoric times indicates that the oxygen content of pristine nature was above the 21 percent of total volume that it is today. It has decreased in recent times due mainly to the burning of coal in the middle of the last century. Currently the oxygen content of the Earth’s atmosphere dips to 19 percent over impacted areas, and it is down to 12 to 17 percent over the major cities. At these levels it is difficult for people to get sufficient oxygen to maintain bodily health: it takes a proper intake of oxygen to keep body cells and organs, and the entire immune system, functioning at full efficiency. At the levels we have reached today cancers and other degenerative diseases are likely to develop. And at 6 to 7 percent life can no longer be sustained.”
Scaremongering? I don’t think so. A reason for doom-saying? Not yet. What is needed is an authoritative evidence-based investigation to accurately ascertain current oxygen levels and what consequences, if any, there are for the long-term health and well-being of our species – and, indeed, of all species.
In his 1990 essay, “Carbon Dioxide in the Atmosphere and Biosphere,” the British-born physicist Professor Freeman Dyson argues the need to monitor and record oxygen depletion, in order to assess its long-term implications:
“The Pacific Ocean as a whole is already seriously depleted. It contains 50 percent of the planet’s water but only about 40 percent of the dissolved oxygen. So long as we are not measuring the rate of depletion year by year we have no basis for guessing how soon the asphyxiation of parts of the ocean might begin.”
“The reservoir of oxygen in the atmosphere is large but not infinite. It amounts to 1.2 million gigatons. Since eight tons of oxygen are used up for every three tons of carbon burned, and we are burning six gigatons of carbon per year (he was writing in 1990 before India’s and China’s massive industrial expansion), we might expect that the oxygen is being used up at the rate of about 13 parts per million per year. Thirteen parts per million should be measurable.”
Majid Ali is a former Professor of pathology at New York’s Columbia University. In his book, “Oxygen and Aging” (Canary 21 Press, Denville, New Jersey, 2003), he discusses his clinic’s use of oxygen therapies in tandem with conventional medicine: “Oxygen is nature’s primary antibiotic. Oxygen is the weapon used by the immune system to kill bacteria, viruses, yeasts, and parasites. The mechanisms used by the hunter immune cells to immobilize, capture, kill, and digest microbes (as their food) are all triggered and maintained by oxygen-related biochemical events. For example, when a hunter immune cell (phagocyte) comes into contact with a microbe, it releases reactive (nascent) oxygen, which directly oxidizes the components of the microbial surface and kills it.” (pp.86-87)