Trigger Warning! What follows is likely to challenge whatever you might think you know about climate change. Continue reading at your own risk.
For many years, there has been an entirely natural process operating that has been removing a critical nutrient from the environment. If allowed to continue unabated, it could deplete this nutrient to the point where all life on earth would die. All the land areas would look like the lifeless landscapes we see in pictures of Mars or the moon, and the oceans would be without life from their surfaces to their deepest depths.
The depletion process has nothing to do with human activities. It has been operating for many, many more years than humanity has been in existence. We find evidence of this activity on every continent of the Earth and throughout its oceans. Vital supplies of this critical nutrient are locked in huge rock deposits across the globe. New rock formations sequestering this nutrient are being formed daily, further reducing the supply. One might think of this process as a slow form of the suicide of Nature.
The nutrient is already scarce in the environment, being present in its free form in less than 1/20th of one percent. Not so long ago, it dipped to less than 0.018 percent. If it gets below 0.015 percent, there will not be enough available to support life. Within our oceans there are vast populations of organisms that capture this nutrient and incorporate it into hard shells and skeletons. When these organisms die, their shells remain and fall to the ocean floor to add to the slowly accumulating sediments that form future limestone deposits.
Limestone is often used as an attractive building material due to its wide abundance and relative ease of cutting and shaping. If one looks closely, one can see the shells and skeletons of the uncountable organisms that contributed to the creation of these rocks in millennia past. In some parts of the world, these deposits now stand above the surface, forming the foundation for many islands. The Cayman Islands as well as the Bahamas and Bermuda islands are a form of limestone built by corals.
Corals and shell-forming organisms like clams and oysters extract calcium and dissolved carbon dioxide from the surrounding water. They combine these to form calcium carbonate, the hard mineral that forms their shells, skeletons, and ultimately, limestone. For most of the Earth’s history, the levels of this nutrient were over ten times greater than today. Over many millions of years, these carbonate-forming organisms have been acting to reduce this nutrient to the dangerous levels we observe today.
Fortunately, human as well as natural activities have acted to increase the environmental levels of this nutrient. While it is still at dangerously low levels, the effects of the small increase managed so far have been dramatic. Across the globe, the plants that require this nutrient have responded enthusiastically to the increase.
Satellite measurements of plant coverage show at least a 30% increase in plant coverage. Crop yields have grown significantly, in some cases more than doubling previous yields, resulting in a huge decrease in world hunger, despite population growth. Regions that were arid wasteland just a few decades ago have become fertile grasslands and woodlands, due almost entirely to the tiny increases in this nutrient. Indeed, over roughly the last 100 years, the abundance of this nutrient has only increased by about 0.008 percent – from 0.032 percent to 0.040 percent.
There is a good indication that if we could raise the level of this nutrient to .12 to .15 percent, we could restore most of the world’s deserts to the grasslands and forests they once were. Imagine the area we currently know as the Sahara Desert restored to the broad savannahs and forests that existed only a few millennia ago.
By now, many of you have realized the nutrient of which I write is carbon dioxide. If you look at a tree or bush, or even grass, almost everything you see is literally made from thin air. Living plants need carbon dioxide. They extract it from the air, and using sunlight and water, convert it into the sugars and other molecules they use to make wood and seeds, and fruits and grains. The soil supports them, provides water, and a few necessary minerals, but little else.
You can see this when you burn wood. The small quantity of ash that remains after the wood is burned, is all that was obtained from the soil. All the rest that burned to provide heat and light came from the carbon dioxide in the air and the energy of sunlight stored in the wood. Combustion simply restores that which was taken from the air to be re-used over and over by other plants. The fruits and grains that plants produce provide the food that animals and humans require. These, too, are made from the carbon dioxide of the air, sunlight, water, and a few minerals from the soil.
Less obviously, the oceans also depend on this airborne nutrient. Tiny plants that float near the surface of the oceans also take the carbon dioxide that dissolves in the water from the air, combine it with the energy from sunlight and make the substances on which zooplankton – the miniscule animals swimming in the surface waters – depend. These in turn are consumed by fish and other life in the sea, including even whales. Without these tiny plants building the basic foodstuffs from carbon dioxide and sunlight, the oceans would be lifeless and barren. There would be no shrimp or herring, no tuna, no seals, no sharks, nor whales.
Humans and animals need oxygen to survive, but if the quantity of oxygen in the air is too low, we die, even if the total amount of air is large. So it is with plants, but for them, it is carbon dioxide, not oxygen that counts. If the quantity of carbon dioxide in the air is too low, then plants die, just as animals die from lack of oxygen. The critical level of carbon dioxide needed for survival is about 0.015 percent. At this level, plants are starving, gasping for the air they need to survive. As people who operate greenhouses know, plants are much happier when carbon dioxide levels are six to ten times higher than this minimum. They grow faster, are sturdier, produce more fruit, and are generally healthier. When plants are healthier, the people and animals that depend on them are also healthier and happier.
Recently there have been misguided attempts to promote removal of carbon dioxide from the atmosphere under the mistaken assumption that carbon dioxide is a toxic substance. Many have accused carbon dioxide of being responsible for the slow warming that has taken place for the last 350 years since the Little Ice Age, a time when global temperatures reached their most recent periodic low point. These accusers point to the coincident rise in carbon dioxide concentration and temperature as proof that increases in carbon dioxide are causing the temperature to rise.
Interestingly, there is substantial evidence that the rise in carbon dioxide in the atmosphere is due to rising temperatures. The oceans contain vast quantities of dissolved carbon dioxide that is released as the oceans warm, just as a carbonated beverage releases its dissolved carbon dioxide and goes “flat” as it warms. Several studies of ice core data from Antarctica and Greenland, as well as ocean sediment studies consistently show this process of a temperature rise preceding a rise in atmospheric carbon dioxide. The natural warming since the Little Ice Age would bring about slow warming in the oceans, causing them to release some of the dissolved carbon into the atmosphere.
Many of these accusers, including a number of prominent scientists, are very confident that human carbon dioxide emissions are causing the rise in temperatures, despite the fact that the temperature rise began 200 years before humans began using fossil fuels. It might help to remember that the leading scientists of the day were very confident that the sun, stars and planets revolved around the earth. The fact that many of the accusers stand to gain greatly in power or economic terms from projects to reduce carbon dioxide does not inspire great confidence in their motives.
In any case, were the natural decline in the concentration of this vital nutrient allowed to continue unchecked, the Earth would become a lifeless ball in a relatively short time. It is fortunate that human activities are able to forestall this slow suicide of Nature by restoring to the atmosphere some of the carbon dioxide that has been naturally sequestered. We have only just begun, though. There is much to do yet to bring levels of this life-sustaining nutrient up to healthy levels. We cannot afford to let the misguided efforts of a few interfere with this vital work.
By David Robb
David Robb is a regular contributor to The Blue State Conservative and a practicing scientist who has been working in industry for over 50 years. One of his specialties is asking awkward questions. A large part of his work over the years has involved making complex scientific issues clear and understandable to non-specialists. Sometimes he even succeeds.
Featured photo by Geralt at Pixabay.