Question

Which of the following questions about greenhouse effect is true?

Group of answer choices

Greenhouse gases are transparent to shortwave solar radiation but absorb longwave thermal radiation

Greenhouse gases absorb shortwave solar radiation and reradiate it as longwave thermal radiation

Carbon dioxide is the only important greenhouse gas because it remains in the atmosphere longer than all other gases.

Greenhouse gases reradiate thermal energy in the direction of space only.

Question 2:

Of the following choices choose one that is an example of a negative feedback loop.

Group of answer choices

Increasing temperature increases the water holding capacity of the atmosphere, causing water vapour in the atmosphere to increase. Since water vapour is a greenhouse gas, this will result in further temperature increase.

Elevated atmospheric CO2 increases plant growth rates, which in turn results in increased photosynthesis and carbon sequestration, lowering atmospheric CO2

The solubility of CO2 decreases as ocean temperature increases, which means that oceans will take less CO2 as they warm, leaving more CO2 in the atmosphere

Increasing temperature causes declines in snow and ice caps, lowering albedo, which in turn results in increasing temperatures

Answer 1

1. the correct answer is Greenhouse gases are transparent to shortwave solar radiation but absorb longwave thermal radiation

the greenhouse gases allow the short wave and high energy UV rays to pass through them. The earths surface absorbs this and reemits it as longwave IR radiations which cannot penetrate the greenhouse gas layer and hence get reflected back.

The major greenhouse gases are water vapor, carbon dioxide (CO2), methane, nitrous oxides, and chlorofluorocarbons (CFCs). It sis the abuntant production of CO2 that makes it the most vulnerable green house gas.

2.the answer is Elevated atmospheric CO2 increases plant growth rates, which in turn results in increased photosynthesis and carbon sequestration, lowering atmospheric CO2

in a feedback loop regarding the climate change ;positive feedback accelerates a temperature rise, whereas a negative feedback slows it down.

the elevated CO2 level causes a greater availability of CO2 for the plants and thereby increases the plant growth rates to a certain extent especially the plants which have higher CO2 tolerence rates and this thereby lowers the CO2 level.

in other options the end result is the increase in the rate of climate change and are hence positive feedbacks.