Climate variability

Research undertaken through the ACCSP improved our understanding of natural climate variability, and how this might change in the future.

An important aspect of this work was determining how the global water cycle will change, and the impact of these changes on Australian rainfall.

ACCSP scientists played major roles in understanding the nature of the El Niño–Southern Oscillation, quantifying its impact on the climate, and estimating how its impact on rainfall will change in the future.

Researchers also examined how much of the change in our climate can be attributed to natural variability and how much is due to greenhouse gases.

ACCSP science highlights

• Understanding the impact of the Indian Ocean Dipole on Australian climate—at the outset of the ACCSP we did not know about the Indian Ocean Dipole; now we know in its positive phase it brings drier conditions to south-eastern Australia from winter through to spring.
• Determining that the Southern Annular Mode is likely to trend towards more positive values in a warming world, leading to drier conditions across south-eastern Australia in winter.
• Determining that extreme climate and weather events in regions affected by the positive Indian Ocean Dipole may become more frequent as temperatures rise.
• Determining that extreme El Niño–Southern Oscillation events are likely to occur twice as often in a warming world.
• Determining that the Australian monsoon, which is responsible for most of the heavy rain that falls across northern Australia, could become more variable from year to year by the end of this century, with wet years becoming wetter and dry years becoming drier.
• Analysing salinity patterns in the global oceans to identify the intensification of the global water cycle (i.e. dry regions have become drier, and wet regions have become wetter).