Chapter 12

There are more gases than these, but these above gases are the most critical for the Earth's climate and they also compose greater than 99.99% of the atmosphere. Technically the percentages here add to over 100% because water vapor is included.

(Purple) Nitrogen, (Yellow) Argon make up ~79% of the atmosphere.

(Dark Blue) Water vapor is not normally included as part of the atmosphere, water vapor dominates the behavior of the atmosphere at ~1%.

(Light Blue) Oxygen is ~21% of the atmosphere. Ozone is included, but does not even have a concentration of 1 ppmv.

The Troposphere is the part of the atmosphere in which we live. Most of the atmosphere's mass is within the Troposphere. The Stratosphere is warmed by the ozone/oxygen absorption of UV from the Sun.

(Red) CO2 accounts for ~2% of 2% of the Earth's atmosphere.

Wearing a hat in cold weather is a good analogy to CO2 in the atmospheric energy balance. Changing to a better hat is what increasing CO2 does.

The total Greenhouse Effect is a function of how much energy is transferred to the atmosphere. This is a summary of the parts that transfer energy to the Earth's atmosphere.

Saying the Earth has a 33 °C greenhouse effect when the actual total varies proves that the effect is not a constant based solely on the Earth's atmosphere.

The amount of energy leaving the Earth's atmosphere is not dependent on the amount of energy the Earth is receiving from the Sun. It also is dependent on the season of the Northern Hemisphere.

CO2 is significant to the total GHE only if the assumption is used that greenhouse gas absorption is the ONLY method of energy transfer. For 62% cloudiness this is the energy impact by greenhouse gas absorption only.

This uses the ~radiative flux of the atmospheric gases instead of the amount of energy transferred as a result of each greenhouse gas. This is the best way to show that a change in CO2 levels could have a measurable impact.

(Dark) Blackbody Prediction. (Light) Actual surface temperature of the Moon in 1972.

(Light) Subsurface temperature. (Dark) Surface temperature from Apollo 15. The different high temperatures on the Moon are precisely in line with the distance from the Sun. January is closest to the Sun, so the daily temperature is higher.

OLR is highest in places with high temperature and low humidity. It is lowest in places with low temperature.

(High) 1km Horizontal Transmittance (Low) Transmittance from Sea level to 100km Vertical. I added 15 to the x-axis as that is the peak CO2 absorption. Notice how little difference there is between 1km of atmosphere and 100 km of atmosphere for IR transmission in the CO2 spectrum.

The band that CO2 can absorb. Courtesy of SpectralCalc.com

Supercells can prevent almost all sunlight from reaching the Earth's surface. CO2 acts in an identical fashion at blocking the 14-16 micron wavelength from reaching space. Martin Lisius/StormStock

Visibility is a measure of how much light is being absorbed by water in the air. Doubling the fog cuts in half the distance that light will travel before being absorbed. Courtesy of GPB.org.