re: #172 BrainSurfer

“full of normal atmosphere”… in a greenhouse? What about the sun, cosmic rays, clouds, the oceans?? You want to cherry pick the scenario to fit your idea of global warming. The earth system is far too complex to try to simplify it down to a greenhouse and increasing CO2.

Besides if you overlook history, you are severely limiting your overall understanding of the how complex the earth’s entire ecosystem is. Is man screwing things up - certainly. Do we have all the answers on exactly how we are screwing things up - definitely not.

That is nothing but an argument from ignorance, the belief that since we don’t know it all we don’t know anything. We may not know everything but we do know enough, and we understand the complexities very well, to know CO₂ is trapping warmth and slowing down the radiation of heat from the atmosphere.

Energy in all wave lengths hits the surface of land, water, ice, snow and everything that isn’t bounced back as is contributes to heat increases in all surfaces, including melting of ice, and is re-radiated as energy in the IR wavelengths. CO₂ is warmed up by this IR and through convection and conduction passes this warmth off to the N₂ and O₂, and through radiation heats up other CO₂ molecules.

Heat can only escape the atmosphere through radiation.

Since a molecule of CO₂ doesn’t just re-radiate up and to the sides, but also back toward the surface, surface cooling is slowed down. It’s this slowdown of heat reaching the upper atmosphere where it can re-radiate to space that is warming the climate.

Natural variations, ocean circulation, melting ice and human introduced aerosols tend to dominate the trend so it looks less steep than it is.