You take a rock, orbit it around a light source called a sun, and eventually after millions of years, life appears.
What key ingredients were needed for a successful experiment to take a lifeless rock and create a carbon-based lifeform?
One of those intelligent lifeforms may guess oxygen (O2) and water (H2O).
He would be close.
The answer is carbon dioxide (CO2), and H2O.
From the miracle of photosynthesis, the experiment is a success.
Photosynthesis in plants with chlorophyll takes the energy of the sun and converts CO2 and H2O to sugar (C6H12O6) and O2.
Like magic, life is possible because the energy of the sun has been converted to a form usable by all life on earth.
Without CO2, life is impossible.
Oxygen was not even needed since it is a product of the reaction.
Photosynthesis is indeed good.
Is there anything that may make life impossible on Earth?
Yes, if intelligent lifeforms attack CO2.
Because of the nature of mankind, the experiment can still be a failure.