What is the greenhouse effect, and how does human activity contribute to it?
-
A
The greenhouse effect is harmful in all cases; humans cause it by building greenhouses for agriculture
-
B
The greenhouse effect is a natural process where atmospheric gases trap heat; human activity enhances it by increasing greenhouse gas concentrations through burning fossil fuels
-
C
The greenhouse effect is caused entirely by volcanic activity; humans have no influence
-
D
The greenhouse effect refers to light pollution in urban areas