What can you infer from the fact that global warming has only been a problem for the last 100 years or so?
A. Prior to 100 years ago, the greenhouse effect on the earth was too minor to be detected. incorrect answer
B. The earth moved significantly closer to the sun about 100 years ago. incorrect answer
C. People have only been pumping large quantities of greenhouse gases into the atmosphere for 100 years or so. incorrect answer
D. The movement of glaciers was a major problem for people 100 years ago. incorrect answer