UGC NET Questions (Paper – 1)

The natural greenhouse effect keeps Earth warm enough for life by trapping some outgoing infrared radiation. Human activities such as burning fossil fuels and deforestation have increased greenhouse gas levels,leading to extra warming beyond this natural level. This extra warming is known as the enhanced greenhouse effect. Therefore enhanced is the correct word to complete the phrase in the stem.

Option A:
The natural greenhouse effect refers to the baseline warming that has always existed due to naturally occurring greenhouse gases. It is essential for maintaining habitable temperatures and is not the additional human induced component highlighted in the question.

Option B:
Moderate does not correspond to any widely recognised term in climate science. While the enhanced greenhouse effect may or may not be moderate, the established term focuses on the idea of being stronger than the natural effect,not moderate.

Option C:
Shielded greenhouse effect is not an accepted expression. Shielding would imply blocking radiation rather than trapping more of it. Thus this option does not fit the phenomenon described in the stem.

Option D:
Enhanced greenhouse effect clearly indicates that the original process has been intensified by human actions. It accounts for the observed trend of rising global temperatures and changing climate patterns,exactly what the question refers to.