This paper integrates the factors that are reported in the scientific literature about global warming caused by greenhouse gases and about global temperatures on planet earth since it was created 4.6 billion years ago. According to scientific reports, the terrestrial and ocean surfaces are warmed by infrared radiation of solar energy. The earth's atmosphere is heated by infrared radiation from the terrestrial and ocean surfaces, as well as from solar energy, and by the action of greenhouse gases, especially carbon dioxide and methane (natural gas). There is a general correlation between the average earth's atmospheric temperature and the atmospheric carbon dioxide content. The current concept of global warming is "A rapid increase in earth's surface temperature." Scientific reports show that rapid increases in the earth's surface temperature and atmospheric carbon dioxide began in about 1980; hence we are experiencing global warming. It is generally accepted that when global warming occurs, climate changes such as extreme storms, flooding, hurricanes, extreme blizzards, increased glacial melting, forest fires and drought tend to happen.