This report summarises our current understanding of Australian climate drivers and recent advances in climate research, with a particular focus on topics covered by National Environment Science Program 2 (NESP 2) Project 1.4 (Understanding Climate Variability).
This project aims to improve our understanding of the impacts of the complex interplay between naturally occurring climate variability and anthropogenic climate change. Combining analysis of state-of-the-art climate model output and observational data has given us new insights into the physical processes underlying the El Niño Southern Oscillation (ENSO), the Indian Ocean Dipole (IOD), the Southern Annular Mode (SAM) and the Australian Monsoon. ENSO variability is projected to increase over coming decades, along with more frequent extreme ENSO events. Strong positive IOD events are also projected to increase. These projected changes would result in overall less rainfall and warmer temperatures over Australia during winter and spring. Under high emissions scenarios, SAM is projected to experience a shift towards a positive state, associated with increased rain over eastern Australia. Long term projections of changes to the northern Australian monsoon remain uncertain. The researchers working within this project are working to refine our understanding of these projections and the physical processes behind the interaction and changes occurring in these climate drivers.