Question

Oxygen (O2) and nitrogen (N2) do not have much greenhouse effect, but several trace gases including carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and various chlorofluorocarbons are important greenhouse gases. The primary mechanism by which these greenhouse gases warm the Earth is: Group of answer choices

Answer 1

Full Question:

Oxygen ($O_2$) and nitrogen ($N_2$) do not have much greenhouse effect, but several trace gases including carbon dioxide ($CO_2$), methane ($CH_4$), nitrous oxide ($N_2O$), and various chlorofluorocarbons are important greenhouse gases. The primary mechanism by which these greenhouse gases warm the Earth is:

A. Making politicians mad, so they give speeches that heat the air.

B. Experiencing chemical reactions with each other, which release energy.

C. Preventing convection currents that take heat aloft, in the same way that the glass of a greenhouse stops convection currents and so makes the air in the greenhouse warmer.

D. Raising the atmospheric pressure, because squeezing air warms it, as we saw at the Redwoods.

E. Absorbing some of the infrared radiation emitted from the Earth.  

Answer:

The primary mechanism by which these greenhouse gases warm the Earth is absorbing some of the infrared radiation emitted from the Earth.

Option E

Explanation:

Though the pressure does not set the temperature, but the changes in pressure brings changes in temperature. The rare greenhouse gases does not affect the pressure much. The imbalance in greenhouse gases are very less when compared to the effects of radioactive gases. Greenhouse glass blocks the convection currents which is not blocked by greenhouse gases. The infrared radiation emitted from the planet is adsorbed by $CO_2$.

The $CO_2$ move into excited state by the infrared photon absorption which quickly returns to the normal state by emission of photon with same energy. These photons emitted from this excitation comes towards Earth which helps in trapping the energy of warming the planet which achieves new balance.