A Scot, Joseph Black discovered Carbon Dioxide in 1755 

The Discovery of Carbon Dioxide

In Black’s early years at Glasgow, he probably started his work on the chemistry of “magnesia alba“. He submitted his work later for his MD thesis in Edinburgh including the discovery of what we now call carbon dioxide, Joseph Black called it “fixed air“. Black observed that the fixed air was denser than air and did not support either flame or animal life. Black also found that when bubbled through an aqueous solution of lime (calcium hydroxide), it would precipitate calcium carbonate. He used this phenomenon to illustrate that carbon dioxide is produced by animal respiration and microbial fermentation. These works foreshadowed Lavoisier’s work, and highly contributed to the foundations for modern chemistry.[4,5]

Before life on earth began, the atmosphere was likely mostly carbon dioxide.

Carbon Dioxide is the gas of life:

……… CO2 is more than merely a plant fertilizer, as important as that is. CO2 is also a pollution
fighter. The gas of life – this miracle molecule – does not merely enable land, lake, river and ocean
plants to grow and prosper. It doesn’t just make life on Earth possible, and enhance our health,
welfare and environmental quality

Scientists have realised the earth evolved an oxygen cycle and a carbon dioxide cycle which created life. See biology dictionary..

The oxygen cycle and the carbon dioxide cycle (carbon cycle) are two of the biogeochemical cycles on Earth that make life possible. They act separately but are dependent on each other because the carbon cycle gives off oxygen for the oxygen cycle to use, and in turn, the oxygen cycle emits carbon dioxide (CO₂) which goes back into the carbon cycle. Plants are the main vehicle by which the oxygen and carbon cycles are connected. Respiration, combustion and decomposition are three other ways that CO₂ and/or oxygen is released back into the atmosphere. Another biogeochemical cycle, the hydrogen cycle, connects some of the pathways in nature that are involved in the carbon and oxygen cycles.

……….Life on Earth is based on carbon. The carbon reservoirs are the atmosphere, the biosphere, the oceans, sediments (including fossil fuels) and the mantle and crust of the planet. Carbon dioxide and methane are the two principal forms of carbon in the atmosphere. Plants take in CO₂ and water to create sugars like glucose through the process of photosynthesis. The plants then release oxygen and water vapor as byproducts. The oxygen goes back into the oxygen cycle and the water vapor enters the water cycle. Without plants, CO₂ would build up to dangerous levels in the atmosphere and add to the greenhouse effect. About 500 gigatons of carbon are stored in the plants and animals that live on the surface of the planet and the soil holds about 1,500 gigatons.

Like the carbon that is used during photosynthesis, the carbon in the oceans, sediments, mantle and crust of the planet has been moving through the carbon cycle for hundreds of millions of years. Carbon can be cycled through the various processes over the course of days, weeks, months or years. It can take tens of millions of years for carbon stored in the ocean floor to be released, if it is ever released at all. Volcanic eruptions are one way that carbon-containing molecules from deep within the planet are released to the surface. The combination of burning fossil fuels (releasing CO₂) and deforestation (reducing photosynthesis and carbon storage) caused by humans is disrupting the carbon cycle in a negative way

To me, the Yin-Yang symbol represents the ideal of homeostasis, which we have now lost due to our human activities wrecking the Carbon Cycle.

Ancient Taoist philosophy believes peace and abundance can only take place when there is balance and harmony between yin and yang.