When one learns that carbon dioxide and water vapor are trace gases, it’s tempting to dismiss the strength of their blanketing effect on infrared radiation (heat). However, consider that if you could bring all the clouds and water vapor in the atmosphere to the surface, it would form a ‘liquid’ layer less than an inch deep, and clouds alone would create a layer no deeper than a coat of paint. If just this past year’s carbon dioxide emissions could be confined to an undiluted layer of pure CO2 at the surface of the Earth, the layer would be about 1.5 inches thick. Now, multiply that.....
Water Vapor:
https://en.m.wikipedia.org/wiki/Water_vapor
Carbon Dioxide and Water Vapor As Greenhouse Gases:
https://www.scientificamerican.com/article/if-carbon-dioxide-makes-u/
Past CO2 Levels:
https://www.climate.gov/sites/default/files/paleo_CO2_2018_1500.gif
Note: The CO2 levels of the past have been sufficient to keep the Earth from freezing completely over for the past 640 million years, which was what happened on three separate occasions when CO2 levels got too low:
https://samslair.blogspot.com/search?q=Snowball+Earth+&m=1
