( ( ( Carbon dioxide ) ( -LRB- ( CO2 -RRB- ) ) ) ( ( ( ( ( is ( released ( into ( ( the atmosphere ) ( byburning ( ( fossil fuels ) ( such ( as ( coal ( , ( ( oil and ) gas ) ) ) ) ) ) ) ) ) ) ) , ) and ) ( is ( ( the maincontributor ) ( to ( climate change ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Carbon) (NN dioxide)) (PRN (-LRB- -LRB-) (NP (NNP CO2)) (-RRB- -RRB-))) (VP (VP (VBZ is) (VP (VBN released) (PP (IN into) (NP (NP (DT the) (NN atmosphere)) (VP (VBG byburning) (NP (NP (JJ fossil) (NNS fuels)) (PP (JJ such) (IN as) (NP (NN coal) (, ,) (NN oil) (CC and) (NN gas))))))))) (, ,) (CC and) (VP (VBZ is) (NP (NP (DT the) (NN maincontributor)) (PP (TO to) (NP (NN climate) (NN change)))))) (. .)))
Carbon dioxide (CO2) is released into the atmosphere byburning fossil fuels such as coal, oil and gas, and is the maincontributor to climate change.
(ROOT (S (NP (JJ Co2) (NN gas)) (VP (VBZ is) (VP (VBN released) (PP (IN into) (NP (NP (DT the) (NN atmosphere)) (SBAR (WHADVP (WRB when)) (S (NP (JJ fossil) (NNS fuels)) (VP (VBP are) (VP (VBN burned))))))))) (. .)))