Answer:
Earth's earliest climates, before 4000Ma, reflected a relatively faint young Sun and a soupy greenhouse atmosphere rich in dust and gas, such as CO2 and NH3, generated by asteroid impacts, magmatic degassing, and high radioactive heat flux.
In 1953, S.L. Miller created primitive earth conditions in the laboratory and gave experimental evidence for origin of first form of life from pre-existing non-living organic molecules. The primitive earth conditions created include.