Atmosphere: CO2 on my mind

By Daniel Lux

Have you ever been in a room where the air gets heavy - like a classroom?

At first, it becomes challenging to concentrate, and drowsiness slowly sets in. Then, a headache app

• Language: English
• Publisher: TramLux ApS
• Release date: Feb 20, 2022
• ISBN: 9788797376218

Book preview

Introduction

The defining feature of humans is our intelligence. How does a changing composition of earth's atmosphere directly affect the human body and mind?

Atmosphere, CO2 on my mind" uses a scientific approach, intertwined with storytelling, to explain how the changing composition of the air that we breathe affects our bodies and minds. In three parts the story is told including illustrations and references to scientific papers

To understand how life and our atmosphere are connected, we start by looking at our past. The first atmosphere of our Earth was very much like that of Mars and Venus. But life itself terraformed our planet into a habitable place for numerous lifeforms. From time to time, this change in the atmosphere causes extinctions. But the extinction events also drove evolution forward to new heights. Without change, there is no incentive to explore new radically different solutions. The same also holds for the evolution of us, homo sapiens. During our evolutionary development, which resulted in us giving ourselves the title sapiens, translated to wise, we have experienced a very stable composition of the atmospheric composition. Simplistically speaking, evolution is the process of adaptation to the environment. Can we evolutionarily adapt fast enough to the extremely rapid change in our environment caused by climate change?

To understand the task at hand, we must first understand what a changing composition of the air we breathe does to our bodies. The crews of spaceships and submarines already today experience a different mixture of the air they inhale. Scientists have documented the effects that a spacecraft and a submarine have on the passengers of these vehicles. Medical science has in great detail explained how our pulmonary system (our breathing cycle) works. We are missing the link towards the change in the air we breathe, however. What are the long-term effects of higher CO2 levels and lower O2 levels? What are the effects on infants?

It is easy to avoid catastrophe, and we just need to do the right things right. And herein lies the challenge. What are the right things? We know that we have to stop using fossil fuels. The path forward, however, is not that clear. The currently broken scheme of accounting for our emissions needs fixing. The electricity demand will increase, potentially by a factor as high as ten. Fossil fuels are not only used to produce energy. Fossil fuels are components of numerous daily live objects, such as toys, wrapping materials, detergents, perfumes, and many more. We need replacements for all the things that today require fossil fuels, and maybe mother nature can contribute?

Climate change is highly unfair. The nations that caused our calamities are not the ones feeling the most brutal impact. We cannot solve our challenges if we keep working with a them and us mindset. Working in collaboration with developing countries might, however, solve multiple challenges in the most efficient way. Large areas in developing countries are turning uninhabitable, and we need to change this development. Coincidentally the same regions have abundant resources in solar energy, heat, and relatively cheap labour. Developing countries are part of the solution, and if we help them, we help everyone on Earth.

PART 1 - EARTHS’ HISTORY

1 Flying Reptiles

Approximately 230 million years ago, certain leaping and gliding reptiles evolved into creatures that, with time, formed their separate branch on the reptile tree. Their forelimbs gradually grew long and bladelike, developing into wings with their distinct aerodynamic structure. As cousins of the dinosaurs, the Pterosaurs were the first animals after insects to fly, and they dominated the sky. The pterosaurs spread across the world, and they evolved into a wide variety of species from sparrow size through to giant creatures displaying a 35-foot wingspan. Many animals reside in the air, but the pterosaurs, alongside the birds and bats of today, remain the only vertebrates that have evolved to fly by flapping wings.

Fossil by fossil, hollow bone by hollow bone, we have studied their lives since Cosimo Collini’s first fossil discovery in 1784¹, and we are unearthing anatomy that really captures the human imagination yet these airborne animals, are anatomically rather ill-suited for life in the air.

The pterosaurs belong to a time out of mind. Their awe-inspiring anatomy carried the species through the air for over 160 million years. Yet, their anatomy stands as the very obstacle to our efforts of accurately depicting them and bringing them back into life in our bright minds. The hollow bones that served their flight well have the result that they have literally turned to dust. Sixty-six million years after their extinction, we gradually excavate layer by layer and slowly piecing it together from remnants locked in rocks, fossilized sediments at the bottom of lagoons, and skeletons entombed in limestone. It paints a breathtaking picture of winged giants, the first flying vertebrates and the largest flying animal ever.

The species - or more accurately, the approximately 130 variations on its branch² - took up the Mesozoic skies like today's birds. Scientists believe that they would have resided over different habitats according to sizes and behaviors. Some insect-feeding small creatures quickly fluttered through forests, while other large variations lived off baby dinosaurs and covered huge expanses and oceans.

They stayed on the wing for days, much like today's largest flying bird, the great albatross that is still five to six times smaller than the largest of the pterosaurs despite its grand appearance.

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Illustration of pterosaurs size³

Despite anatomy that puzzles and endlessly fascinates today's scientists, the Pterosaurs' ability to fly was fundamental to their biology. It was the foundation for their dominance of the skies. The question remains, how?

Can't bumblebees fly?

The biology and aerodynamics of the pterosaurs should make flight impossible; they are too heavy and would not be able to deliver the force required to fly - or that is, in today's atmosphere.

If we study the physiology of the pterosaurs in the context of today's atmospheric pressure, their ability to power flight is indeed a mystery. However, we know from tiny air bubbles trapped in amber, that the Mesozoic era's atmospheric pressure and CO₂ levels were higher.⁴ We also know that a combination of increased CO₂ levels and a higher air pressure would have made the air thicker - and thicker atmosphere requires less power to generate flight.⁵

Though we only know them now through their bones and lives unearthed from the ground, these once-imposing kings and queens of the sky navigated their grand bodies through the air with an ease entirely dependent on a particular atmospheric pressure. Higher atmospheric pressure would allow the pterosaurs to power flight through a neat relationship of weight between an object and the surrounding air, much resembling the flight of a hot air balloon.

We achieve flight through the gas inside the balloon - heated air, helium, or hydrogen - because it is lighter than the air it travels through, and in this way, the balloon rises. If the surrounding material around the object - the balloon, the pterosaur - is heavier, then, relatively, the thing becomes lighter, and flight is enabled or becomes easier.

Archimedes’ principle

Approximately 20 kilometers east of Jerusalem lies the dead sea in a barren area ripe with history. For millennia the water of the dead sea has been attributed with healing powers and beauty benefits. Even Cleopatra is said to have imported products from the dead sea to tend to her beauty.

Located at the lowest place on Earth, 423 meters below the sea, the water that the Jordan river pours into the dead sea has nowhere to go. A hot and dry climate makes the water evaporate at astonishing speeds. Combine this with a natural occurrence of salt. As a result, the dead sea is one of the saltiest bodies of water on our planet, with almost ten times more salt than ordinary seawater. 

For those of us who have experienced swimming in The Dead Sea, we know that this requires no physical effort - we float in the water. We float because of the high content of salt in the water, which means that the water of The Dead Sea is denser or, in other words, heavier than normal seawater. Its high salinity implies that humans float in The Dead Sea due to its high density, compared to our average mass. The Dead Sea's high salt content has the effect of making the human body more buoyant.

Now, imagine that you are a lousy swimmer yet kept afloat by the salty water. With a change in the water composition, a dilution of its saline content occurring, your buoyancy in water equally changes, and your body suddenly becomes heavier, requiring much more physical effort to swim.

Similarly, the change in the atmosphere's density caused the bodies of the pterosaurs to be relatively heavier and therefore they ultimately were no longer able to fly the same distances.

The Archimedes principle describes the buoyancy of a body in a liquid.

Archimedes’ principle is a physical law of buoyancy. Archimedes was an ancient Greek mathematician and inventor who lived from 287 to 212 BC. His principle states that any physical object, entirely or partially submerged in a fluid (gas or liquid) while not moving, is acted upon by an upward, or buoyant, force. The magnitude of the force exerted on the body is equal to the weight of the fluid displaced by the body.

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Illustration of Archimedes principle

Extinction of the dinosaurs

The glorious era of the airborne giants ended 66 million years ago when the last of five known mass extinctions within 500 million years hit the Earth. Today, the only colossal wing spans taking up the sky are airplanes.

In Yucatan, Mexico, lies the Chicxulub crater. The crater, buried under the peninsula, bears witness to an impact with devastating consequences. It is 150 kilometers in diameter and 20 kilometers deep. Most of us know this story; the extinction of the dinosaurs after a giant asteroid hit the Earth. Wildfires, almost 1,000 kilometers from the impact center, ravaged the land. A tsunami of unimaginable size was set off from the collision impact, causing almost overnight the beginning of the collapse of the ecosystem, which had been sustaining most of the Earth's animal forms. Initially, this affected mainly the non-avian dinosaurs. Due to their mobility, many pterosaurs could move to more food-abundant areas, but as we know now, they too succumbed, unable to maintain their life form.⁶

The reason for this outcome is found in the air. Alongside the enormous immediate impact that happened on the ground, the asteroid's collision with Earth flung near unimaginable volumes of debris, dust, and sulfur into the stratosphere, disrupting the climate and bringing on severe global cooling. It was a time of minimal light, with dusk-like conditions and little animal life on the planet.

While there was undoubtedly a slowing down in growth, plants were not affected as severely by the darkness caused by the dust covering. With not much animal to plant ratio, the CO₂ dropped dramatically; the plants consumed the CO₂ and, the animals that typically would produce CO₂, did no longer do so, since 75 percent of these had become extinct. So, a drop in CO₂ occurred.

Our atmosphere consists of multiple gases: nitrogen, oxygen, argon, CO₂, and water vapor. While these gases disperse independently of each other, the atmosphere's composition influences the atmosphere's mass. This became the critical change to the lives of these avian lords. Due to a change in the CO₂ level, and a reduction in light, the atmosphere on the planet cooled down, the oceans cooled down – and cooler oceans can absorb more CO₂. Plants consume CO₂, and the atmosphere's composition was changed by plants sucking CO₂ out of the air. While oxygen increased, less water evaporated due to the Earth's cooling down, and the overall atmospheric pressure changed.

The air became thinner, meaning that the pterosaurs relatively became heavier in the air. Their unusual anatomy faced a different atmosphere which altered the course of their lives catastrophically.

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Illustration of a pterosaur, struggling to fly.

These drastic changes to the atmosphere over millions of years meant that life forms equally had to change. The giant pterosaurs could no longer sustain flight, behavior, and life in their physiological form. So, one of the important evolutionary stories finally came to an end.

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