( ( Of ( great concern ) ) ( ( ( is ( ( the amount ) ( of ( carbon dioxide ) ) ) ) ( ( the fires ) ( released ( in ( to ( the atmosphere ) ) ) ) ) ) . ) )
(ROOT (SINV (PP (IN Of) (NP (JJ great) (NN concern))) (VP (VBZ is) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NN carbon) (NN dioxide))))) (NP (NP (DT the) (NNS fires)) (VP (VBN released) (PP (IN in) (PP (TO to) (NP (DT the) (NN atmosphere)))))) (. .)))
Of great concern is the amount of carbon dioxide the fires released in to the atmosphere.
(ROOT (S (PP (IN During) (NP (DT the) (JJ early) (NN paleozoic))) (, ,) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (NP (NN carbon) (NN dioxide)) (PP (IN in) (NP (DT the) (NN atmosphere)))))) (VP (VBD was) (ADJP (RB much) (JJR greater)) (PP (VBN compared) (PP (TO to) (NP (NN today))))) (. .)))