( ( ( ( Within ( the ( past ( 200 years ) ) ) ) or ) so ) ( , ( ( ( increased amounts ) ( of ( carbon ( dioxide ( and ( other ( greenhouse gases ) ) ) ) ) ) ) ( ( have ( been ( released ( into ( ( the atmosphere ) ( due ( to ( human activity ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (UCP (PP (IN Within) (NP (DT the) (JJ past) (CD 200) (NNS years))) (CC or) (ADVP (RB so))) (, ,) (NP (NP (JJ increased) (NNS amounts)) (PP (IN of) (NP (NN carbon) (NN dioxide) (CC and) (JJ other) (NN greenhouse) (NNS gases)))) (VP (VBP have) (VP (VBN been) (VP (VBN released) (PP (IN into) (NP (NP (DT the) (NN atmosphere)) (ADJP (JJ due) (PP (TO to) (NP (JJ human) (NN activity))))))))) (. .)))
Within the past 200 years or so, increased amounts of carbon dioxide and other greenhouse gases have been released into the atmosphere due to human activity.
(ROOT (S (NP (NP (DT The) (NN composition)) (PP (IN of) (NP (DT the) (NN atmosphere)))) (VP (VBZ has) (VP (VBN changed) (PP (IN over) (NP (DT the) (JJ last) (CD 200) (NNS years))) (PP (RB primarily) (JJ due) (PP (TO to) (NP (JJ human) (NN activity)))))) (. .)))
The composition of the atmosphere has changed over the last 200 years primarily due to human activity.