( ( ( The ( basic idea ) ) ( behind ( ( ( the ( greenhouse effect ) ) and ) ( global warming ) ) ) ) ( ( is ( that ( humans ( have ( been ( ( increasing ( ( the amount ) ( of ( ( carbon dioxide ) ( in ( the atmosphere ) ) ) ) ) ) ( by ( ( ( ( the burning ) ( of ( fossil fuels ) ) ) and ) ( ( the destruction ) ( of ( rain forests ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ basic) (NN idea)) (PP (IN behind) (NP (NP (DT the) (NN greenhouse) (NN effect)) (CC and) (NP (JJ global) (NN warming))))) (VP (VBZ is) (SBAR (IN that) (S (NP (NNS humans)) (VP (VBP have) (VP (VBN been) (VP (VBG increasing) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN carbon) (NN dioxide)) (PP (IN in) (NP (DT the) (NN atmosphere)))))) (PP (IN by) (NP (NP (NP (DT the) (NN burning)) (PP (IN of) (NP (JJ fossil) (NNS fuels)))) (CC and) (NP (NP (DT the) (NN destruction)) (PP (IN of) (NP (NN rain) (NNS forests)))))))))))) (. .)))
The basic idea behind the greenhouse effect and global warming is that humans have been increasing the amount of carbon dioxide in the atmosphere by the burning of fossil fuels and the destruction of rain forests.
(ROOT (S (NP (NNP Human) (NNS actions)) (VP (VBZ has) (VP (VBN increased) (NP (DT the) (NN greenhouse) (NN effect)))) (. .)))