( ( ( The ( atmospheric concentrations ) ) ( of ( ( a number ) ( of ( greenhouse gases ) ) ) ) ) ( ( are ( ( increasing , ) ( due ( primarily ( to ( ( the actions ) ( of humans ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ atmospheric) (NNS concentrations)) (PP (IN of) (NP (NP (DT a) (NN number)) (PP (IN of) (NP (NN greenhouse) (NNS gases)))))) (VP (VBP are) (VP (VBG increasing) (, ,) (PP (JJ due) (ADVP (RB primarily)) (TO to) (NP (NP (DT the) (NNS actions)) (PP (IN of) (NP (NNS humans))))))) (. .)))
The atmospheric concentrations of a number of greenhouse gases are increasing , due primarily to the actions of humans.
(ROOT (S (NP (NNP Human) (NNS actions)) (VP (VBZ has) (VP (VBN increased) (NP (DT the) (NN greenhouse) (NN effect)))) (. .)))