Climate change is not all one way. There are cycles. Research on coral areas has shown two cycles, 20-30 years and 50-70 year. The region tested is in the northern Pacific which has a strong influence on Asian Monsoons. The amount of rainfall can vary a lot.
In regard to Australia, the climate varies across the continent. Western Australia is usually out-of-kilter with the rest of Australia. When there are floods in the east there are droughts in the west.
The cycles were discovered by drilling out cores and examining the undersea strata with ultraviolet light, a process called Spectral Luminescence Scanning.
Findings have helped to clarify changes in the climate of Madagascar since 1950. Changes in rainfall and river run off have left their mark. Cycles can be traced as far back as 1708.