Explain why greenhouse gases are essential and yet a concern.

Greenhouse gases are essential for keeping in heat and maintaining the atmosphere, and yet it is a concern. These gases are harmful to the human body and to certain living things, and when the gap lessens between these creatures and the gasses, It creates living conditions that are very inadequate and do not allow life to prosper.

Green house gases are the type of gases present in the air which have the ability to trap heat of the earth's surface. Gases like carbon dioxide and methane are found naturally and are known to play an important role in earth's climate. If they are not found the earth' s climate would be too cold creating problem for survival of life on the earth.

These green house gases absorb the emit the radiation in the thermal infrared range. These gases act like a blanket and save earth surface from infrared radiation by absorbing them and prevent them from escaping out of the earth surface.

But now a days due to increased in the concentration of green house gases like carbon dioxide and methane due to pollution and deforestation causing a great problem called as green house effect which lead to global warming and it a great concern for all the people now a days.  

i think that d. wind is the answer.   i missed the question when i answered a. currents.

i think that is new experiments yield untrustworthy data and should be carefully considered, because you don't know what will happen with the experiments.