( ( Renewable sources ) ( ( could ( ( ( supply ( half ( ( the ( world 's ) ) energy ) ) ) ( by 2050 ) ) ( as ( ( ( oil prices ) and ) ( ( the ( environmental cost ) ) ( of ( using ( energy ( both increase ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (JJ Renewable) (NNS sources)) (VP (MD could) (VP (VB supply) (NP (DT half) (NP (DT the) (NN world) (POS 's)) (NN energy)) (PP (IN by) (NP (CD 2050))) (PP (IN as) (NP (NP (NN oil) (NNS prices)) (CC and) (NP (NP (DT the) (JJ environmental) (NN cost)) (PP (IN of) (S (VP (VBG using) (NP (NP (NN energy)) (NP (DT both) (NN increase))))))))))) (. .)))
Renewable sources could supply half the world's energy by 2050 as oil prices and the environmental cost of using energy both increase.
(ROOT (S (NP (NNP Oil)) (VP (VBZ is) (NP (NP (DT the) (ADJP (RBS most) (RB commonly) (VBN used)) (NN source)) (PP (IN of) (NP (NP (NN energy)) (PP (IN in) (NP (DT the) (NN world))))))) (. .)))