( ( During ( ( ( the ( industrialization era ) ) ( -LRB- ( ( second ( industrial revolution ) ) -RRB- ) ) ) ( over ( the ( past ( few decades ) ) ) ) ) ) ( , ( people ( ( have ( been ( burning ( ( ( ( fossil fuels ) ( -LRB- ( ( ( ( coal ( , ( oil ( , gasoline ) ) ) ) , ) ( natural gas ) ) -RRB- ) ) ) , ) ( which ( ( ( ( releases CO2 ) ( into ( the atmosphere ) ) ) , ) ( causing ( the ( greenhouse effect ) ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN During) (NP (NP (NP (DT the) (NN industrialization) (NN era)) (PRN (-LRB- -LRB-) (NP (JJ second) (JJ industrial) (NN revolution)) (-RRB- -RRB-))) (PP (IN over) (NP (DT the) (JJ past) (JJ few) (NNS decades))))) (, ,) (NP (NNS people)) (VP (VBP have) (VP (VBN been) (VP (VBG burning) (NP (NP (NP (JJ fossil) (NNS fuels)) (PRN (-LRB- -LRB-) (NP (NN coal) (, ,) (NN oil) (, ,) (NN gasoline)) (, ,) (NP (JJ natural) (NN gas)) (-RRB- -RRB-))) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ releases) (NP (NNP CO2)) (PP (IN into) (NP (DT the) (NN atmosphere))) (, ,) (S (VP (VBG causing) (NP (DT the) (NN greenhouse) (NN effect))))))))))) (. .)))
During the industrialization era (second industrial revolution) over the past few decades, people have been burning fossil fuels (coal, oil, gasoline, natural gas), which releases CO2 into the atmosphere, causing the greenhouse effect.
(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))))))))) (. .)))