The key findings of this report includes that by 2030, temperatures will rise by about 1 ºC over Australia – a little less in coastal areas, and a little more inland - later in the century, warming depends on the extent of greenhouse gas emissions. If emissions are low, warming of between 1 ºC and 2.5 ºC is likely by around 2070, with a best estimate of 1.8 ºC. Under a high emission scenario, the best estimate warming is 3.4 ºC, with a range of 2.2 ºC to 5 ºC.
Further, the report indicates there will be changes in temperature extremes, with fewer frosts and substantially more days over 35 ºC.
It also predicts that decreases in annual average rainfall are likely in southern Australia - rainfall is likely to decrease in southern areas during winter, in southern and eastern areas during spring, and along the west coast during autumn. For 2030, there will be little annual rainfall change in the far north.
As with temperature, the report indicates that rainfall projections for later in the century are more dependent on greenhouse gas emissions. Under a low emission scenario in 2070, the best estimate of rainfall decrease is 7.5 per cent. Under a high emission scenario the best estimate is a decrease of 10 per cent.
The report indicates that although there will be more dry days, when it does rain, rainfall is likely to be more intense.
Other findings include:
- droughts are likely to become more frequent, particularly in the south-west
- evaporation rates are likely to increase, particularly in the north and east.
- high-fire-danger weather is likely to increase in the south-east
- tropical cyclones are likely to become more intense
- sea levels will continue to rise.