Indian Ocean Climate Initiative - Western Australia

Previous work

The IOCI research program has been studying the climate of WA’s south west since 1998. Projections under all scenarios and all models point to drier conditions across the south west in the future. The current global climate models all agree on the direction of change in winter (June-July-August, JJA) across the south west.

During the first two stages of IOCI much was learnt about the multi-decadal rainfall decline in the first half of the winter half-year (May to July) over the South west. Key scientific findings included:

• Winter rainfall has decreased sharply and suddenly in the region since the mid 1970s.
• The rainfall decline was accompanied by and apparently associated with changes in the large scale atmospheric circulation that are most likely due to a combination of natural variability and the enhanced greenhouse effect.
• While the role of land cover change is unlikely to be a major factor, it should be recognised as a possible second-order effect.
• There is increased confidence in a temperature rise and a decrease in winter rainfall (by as much as 20 percent relative to the 1960-1990 baseline) by 2030. .

Progress and milestone reports from IOCI Stage 1 and Stage 2 can be accessed here.