(S (S (PP (IN Since) (BASENP (NN 1979))) (COMMA ,) (S (BASENP (ADVP (DT all) (CC but)) (NN four) (NNS years)) (VP (VBP have) (VP (VBN been) (ADJP (JJR warmer) (PP (IN than) (NP (BASENP (NN average)) (PP (IN in) (BASENP (NNP Australia)))))))))) (PERIOD .))