Trivial? Non-Correlative? Less than the natural variation of the ecosystem?
Take your pick. All are correct.
As for your other question, your numbers are incorrect.
In total all man-made greenhouse gases - water vapor included - are a mere .28% which is less than the natural variation of the ecosystem.
Where did you find the 4% you stated?
This site had said natural emissions were about 150 billion tons and human emissions were about 7 billion tons. 7/157 comes to about 4.4 percent: