( ( Emissions ( of ( CO2 ( due ( to ( fossil ( fuel burning ) ) ) ) ) ) ) ( ( are ( virtually ( certain ( to ( be ( ( the ( dominant influence ) ) ( on ( ( the trends ) ( in ( ( atmospheric ( CO2 concentration ) ) ( in ( the ( 21st century ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNS Emissions)) (PP (IN of) (NP (NP (NNP CO2)) (ADJP (JJ due) (PP (TO to) (NP (JJ fossil) (NN fuel) (NN burning))))))) (VP (VBP are) (ADJP (RB virtually) (JJ certain) (S (VP (TO to) (VP (VB be) (NP (NP (DT the) (JJ dominant) (NN influence)) (PP (IN on) (NP (NP (DT the) (NNS trends)) (PP (IN in) (NP (NP (JJ atmospheric) (NN CO2) (NN concentration)) (PP (IN in) (NP (DT the) (JJ 21st) (NN century))))))))))))) (. .)))
Emissions of CO2 due to fossil fuel burning are virtually certain to be the dominant influence on the trends in atmospheric CO2 concentration in the 21st century.
(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))))))))) (. .)))