Question

Which of the following is true with regards to the greenhouse effect?

• A. The average temperature of the earth noticeably rises due to the greenhouse effect.
• B. Incoming UV radiation enters a greenhouse and is absorbed by plants and surfaces inside.
• C. The greenhouse effect happens only with plants grown in “glasshouses” in relatively cold regions.
• D. The greenhouse effect causes global climate change.

Answer 1

The correct option is B Incoming UV radiation enters a greenhouse and is absorbed by plants and surfaces inside.

A greenhouse typically refers to the glasshouses made for plants to survive in relatively colder regions around the world. The incident solar radiation enters the greenhouse, is absorbed by the plants and surfaces inside, while much of the outgoing infrared radiation cannot pass through the glass, and remains trapped inside the greenhouse, resulting in warmth within the greenhouse. The earth too, is referred to as a greenhouse in that much of the incoming heat from the sun in the visible spectrum (after absorption of harmful UV by the ozone layer) is taken in, while the greenhouse gases such as carbon dioxide and methane retain some of the IR radiation emitted by the earth. This results in an overall warmth, helping the atmosphere truly act as a blanket to the earth.