( ( Ocean acidification ) ( ( is ( ( a ( lowered pH ) ) ( of ( ( ocean waters ) ( ( caused ( by ( increased ( carbon ( dioxide emissions ) ) ) ) ) ( into ( ( ( the atmosphere ) , ) ( which ( results ( in ( ( more CO2 ) ( dissolving ( into ( the ocean ) ) ) ) ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Ocean) (NNP acidification)) (VP (VBZ is) (NP (NP (DT a) (VBN lowered) (NN pH)) (PP (IN of) (NP (NP (NN ocean) (NNS waters)) (VP (VBN caused) (PP (IN by) (NP (JJ increased) (NN carbon) (NN dioxide) (NNS emissions))) (PP (IN into) (NP (NP (DT the) (NN atmosphere)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ results) (PP (IN in) (NP (NP (JJR more) (NN CO2)) (VP (VBG dissolving) (PP (IN into) (NP (DT the) (NN ocean)))))))))))))))) (. .)))
Ocean acidification is a lowered pH of ocean waters caused by increased carbon dioxide emissions into the atmosphere, which results in more CO2 dissolving into the ocean.
(ROOT (S (NP (NNP Ocean) (NNP acidification)) (VP (VBZ occurs) (SBAR (WHADVP (WRB when)) (S (NP (NP (JJ excess) (NN carbon) (NN dioxide)) (PP (IN in) (NP (DT the) (NN atmosphere)))) (VP (VBZ causes) (S (NP (DT the) (NNS oceans)) (VP (TO to) (VP (VB become) (NP (NNS acidic))))))))) (. .)))
Ocean acidification occurs when excess carbon dioxide in the atmosphere causes the oceans to become acidic.