The answer is 100%. Three are observable, but the fourth is just a carrier.
The answer is photosynthesis.
<span>Photosynthesis
occurs in the leaves of green plants. During photosynthesis, carbon
dioxide and water are converted into using the energy of
sunlight to glucose and oxygen. After great evolution of plants, the photosynthetic rate was increased. More plants mean more oxygen produced in the process of photosynthesis. Thus, photosynthesis </span><span> is most responsible for the increase in early Earth’s atmospheric oxygen levels.</span>
The global average atmospheric carbon dioxide in 2019 was 409.8 parts per million (ppm for short), with a range of uncertainty of plus or minus 0.1 ppm. Carbon dioxide levels today are higher than at any point in at least the past 800,000 years.The carbon cycle describes the process in which carbon atoms continually travel from the atmosphere to the Earth and then back into the atmosphere. Since our planet and its atmosphere form a closed environment, the amount of carbon in this system does not change.
As population and density and competition increase, the death rate goes along with the positive curve so death rate increases.
