Question

In the greenhouse effect, far infrared radiation is [emitted from / absorbed by / emitted and absorbed by] Earth's surface, and absorbed and re-emitted by [some / all] gases in the atmosphere. These gases have [increased / decreased / been unchanged] in concentration over the past century.

Answer 1

[AI-generated answer — Bot GPT 3.5]

In the greenhouse effect, far infrared radiation is emitted from Earth's surface, and absorbed and re-emitted by some gases in the atmosphere. These gases have increased in concentration over the past century.