( ( Some scientists ) ( ( say ( this ( ( ( ( is just ) ( ( the beginning ) ( of ( a ( coming calamity ) ) ) ) ) , ) ( ( ( ( ( predicting ( that ( ( ( an ( unnatural increase ) ) ( in ( greenhouse gases ) ) ) ( will ( contribute ( to ( ( drastic ( temperature increases ) ) ( over ( the ( next century ) ) ) ) ) ) ) ) ) ) , ) ( melting ( polar ( ice caps ) ) ) ) and ) ( raising ( ( sea levels ) ( enough ( to ( ( flood ( major cities ) ) ( around ( the world ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT Some) (NNS scientists)) (VP (VBP say) (SBAR (S (NP (DT this)) (VP (VBZ is) (ADVP (RB just)) (NP (NP (DT the) (NN beginning)) (PP (IN of) (NP (DT a) (JJ coming) (NN calamity)))) (, ,) (S (VP (VP (VBG predicting) (SBAR (IN that) (S (NP (NP (DT an) (JJ unnatural) (NN increase)) (PP (IN in) (NP (NN greenhouse) (NNS gases)))) (VP (MD will) (VP (VB contribute) (PP (TO to) (NP (NP (JJ drastic) (NN temperature) (NNS increases)) (PP (IN over) (NP (DT the) (JJ next) (NN century)))))))))) (, ,) (VP (VBG melting) (NP (JJ polar) (NN ice) (NNS caps))) (CC and) (VP (VBG raising) (S (NP (NN sea) (NNS levels)) (ADJP (JJ enough) (S (VP (TO to) (VP (VB flood) (NP (JJ major) (NNS cities)) (PP (IN around) (NP (DT the) (NN world))))))))))))))) (. .)))
Some scientists say this is just the beginning of a coming calamity, predicting that an unnatural increase in greenhouse gases will contribute to drastic temperature increases over the next century, melting polar ice caps and raising sea levels enough to flood major cities around the world.
(ROOT (S (NP (JJS Most) (NNS scientists)) (VP (VBP agree) (SBAR (IN that) (S (NP (NP (DT an) (NN increase)) (PP (IN in) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN greenhouse) (NNS gases)) (VP (VBG entering) (NP (NP (NN earth) (POS 's)) (NN atmosphere)))))))) (VP (VBZ causes) (NP (NP (DT an) (NN increase)) (PP (IN in) (NP (NP (NN melting)) (PP (IN of) (NP (JJ polar) (NN ice) (NNS caps)))))))))) (. .)))
Most scientists agree that an increase in the amount of greenhouse gases entering earth's atmosphere causes an increase in melting of polar ice caps.