What can you infer from the fact that global warming has only been a problem for the last 100 years or so?



Prior to 100 years ago, the greenhouse effect on the earth was too minor to be detected.


The earth moved significantly closer to the sun about 100 years ago.


People have only been pumping large quantities of

greenhouse gases into the atmosphere for 100 years or

so.


The movement of glaciers was a major problem for

people 100 years ago.