Finding anthropogenic global warming (AG
W) shapes in the fog of variability is a major challenge, simply because natural climate variability is large. And then the problem becomes attributing those changes to a climate mechanism in an interlinked dynamic climate system.
One of those climate detective stories taking some intriguing twists and turns is the rainfall decline in Western Australia which has been the impetus for the Indian Ocean Climate Initiative (IOCI). Their web site explains:
“In southwest WA, a drying trend has been observed … The rainfall decline has been most apparent in late autumn and early winter, with a major drop in rainfall totals occurring in the 1970s, and possibly another more recently in the 1990s. Averaged across southwest WA, a step decrease in total annual rainfall of almost 10% was seen in the mid-1970s, though individual locations would have experienced a greater decrease.”
Jennifer Marohasy BSc PhD has worked in industry and government. She is currently researching a novel technique for long-range weather forecasting funded by the B. Macfie Family Foundation.