It was 1965 when I was first introduced to the term “greenhouse effect” in biology class, as a student at the Bronx High School of Science. The term “global warming” had not come into usage at that time, at least to my knowledge, but the implications of this effect were clear. One certainly experiences it sitting in a car, without air conditioning. Yet, little did I imagine that the buildup of CO2 in the atmosphere, over time, by combustion of all sorts would challenge life on earth on a scale greater than any war or pandemic, or even all the wars and pandemics combined historically.
The balance of gases in the atmosphere has varied through earth’s history. Originally, earth’s atmosphere, supported microscopic life which was adapted to thrive in an anaerobic environment, consisting of such chemicals as hydrogen sulfide, methane and CO2. Free oxygen, as a gas, was largely absent when oxygen eventually was produced by cyanobacterial
photosynthesis on the order of 2.5 billion years after earth formed. It would prove to be toxic to anaerobes and over time there would evolved bacteria that could utilize oxygen, eventually giving rise to mostly aerobic forms of life, which have ever since predominated at all phylogenic strata.
Over the periods of earth’s palaeontologic history, the temperature and the level of oxygen and CO2 in the atmosphere has varied, but generally slow enough to allow life forms to adapt. Five times through earth’s history however, there have been major extinction events, brought on largely by sudden and severe changes in earth’s atmosphere. The most famous one — but not the worst — being the extinction of about 75% of all life species, including the dinosaurs, 66 million years ago by a large asteroid striking the earth, off the Yucatan Peninsula.
While the blast killed many life forms immediately, it is theorized that through a number of changes brought on in the atmosphere, including molten rock hurled over vast areas, extreme fly ash and ultimately changes in the gaseous balance of the atmosphere is what let to a changes in temperature and breakdown of photosynthesis (destruction of base of food chain) that fostered much of this dying off, in the first 10-100 years depending on what you read. It also happened to be “bad luck” that the asteroid struck an area high in MoS2 (molybdenum disulfide). The sulfur released up into the atmosphere combined with oxygen to form H2 SO4 (sulfuric acid), which further made for a toxic atmosphere.
Green plants are the basis of life as they produce net oxygen (more than they utilize) through photosynthesis and absorb net CO2, to make sugars and starches, which can be complexed with a variety of elements to produce proteins, fats and vitamins. It is interesting to note that the hemoglobin of animal life forms, and the chlorophyll of plant life forms, are near identical molecules, both being polycyclic ring structures, with two side groups differing.
Most importantly, hemoglobin, which keeps us alive, has an iron atom at its center, whereas chlorophyll has a magnesium atom at its center. I see this as an integral relation between the ultimate giver of oxygen and the receiver of oxygen being inextricably bound up chemically and in so many other ways, as to sustain life on earth.
Green plants, including the forests and especially the forests that circle the northern latitudes of earth through North America, Europe and Russia, together with all the other green 2 plants produce about 40-45% of earth’s oxygen, while the phytoplankton of the oceans produce more than 50%. Back around 2017, world forestry collectively lost an area of land about equal to the size of Italy. Each year seems to outdo the next for forestry destruction.
What a horror to think that the Sequoias and Redwoods, some of which are 2,000 years old, are now dying. Even their deepest roots can no longer get water as the very great depths of the water tables in those locations have dried up or nearly so. Lake Mead is turning into a mud pit.
It should stand to reason then, that if we continue this mad path of burning and cutting down the forests of the earth and killing phytoplankton of the oceans, through pollution, changes in salinity, currents and temperatures, we will continue to lower atmospheric levels of oxygen upon which our survival depends, from minute to minute, as does that of most life forms.
Choral reefs are dying, ocean water will become more dilute, altering salinity as the polar caps melt, not to mention levels rising, vast oceanic currents such as the Gulf Stream, which moderates land climate (including in our area) have shifted and continue to do so, and temperature of the water are in flux. All of this is creating areas of hypoxia within the oceans, where nothing can live or thrive. It is my supposition that such areas of hypoxia are developing to an ever greater extent in our atmosphere, independent of what is happening in many cities.
We cannot keep destroying the source of oxygen without altering its atmospheric levels over time. At what point will worldwide hypoxia become such an issue, the people will just be getting buy, lethargically and without the energy to carry on all the tasks we do. Those with heart and respiratory disease will suffer greatly if they survive and many of us with other types of illnesses will succumb to low ambient oxygen. No doubt every effort will be made by individuals to “tank up” on concentrated oxygen but that will ultimately fail. Even those who manage to survive for longer times, such as wealthy people, keeping large reserve tanks on their properties, will eventually run out and will not be able to thrive and get around normally.
How will planes stay in sky and our combustion driven cars run – will they sputter and stall out? Most of all how will we thrive and survive?
At the top of Mount Everest, the oxygen level is about 33% of what it is at ground level and evidently blood oxygen falls to as low as 60% at that height, which if kept up is incompatible with survival. That is why oxygen tanks are needed for those “mountain climbing.” Most likely the Sherpas who guide and outfit the visiting hikers, have adapted over time to the lower oxygen levels at great heights. It is known for instance that the people living in the Andes and Himalayan regions have adapted over time such that their hemoglobin saturation levels are greater and how oxygen is released and utilized by the body make them more adaptable to high-altitude living. There are other physiologic changes as well. But these are specific, unique populations. Most people of planet earth would not fare well at constant low oxygen.
It is my belief, that it will not be the runaway, forest fires per say, or the flooding, or larger and more powerful hurricanes, or even the global heat itself that will do us in, but that ultimately it will be some form of worldwide hypoxia that kills us off as life entity, a civilization, a humanity. When I hear Congress talking about aiming for 50% reduction or the like by year 2030 or all the other anemic plans, I realize that relatively few people see this as a crisis.
The entire pandemic, as bad as it was, will just be absorbed into what is to come environmentally if we do not take drastic action to meet an ever-increasing severe global disaster. Polite, one-sided legislation just won’t solve it.