(S (S (NP (NP (BASENP (NN Carbon) (NN dioxide) (NNS concentrations)) (PP (IN in) (BASENP (DT the) (NN atmosphere)))) (PRN (COLON --) (NP (BASENP (DT a) (JJ separate) (NN measure)) (PP (TO to) (BASENP (NN carbon) (NNS emissions)))) (COLON --))) (VP (VBD had) (VP (ADVP (RB also)) (VP (VBN increased) (PP (IN at) (BASENP (DT an) (JJ unprecedented) (NN rate))))))) (PERIOD .))