The State of the Climate report is produced every two years by the Bureau of Meteorology and CSIRO. It provides an overview of the latest knowledge on how the climate is changing and how it will continue to change in the future.
The report draws on a range of national and international sources, including national projections data and information provided through the Climate Change in Australia website and past observational data from the Australian Bureau of Meteorology.
Australia’s climate has warmed by about 1.4 °C since 1910, leading to an increase in the frequency of extreme heat events.Warming has occurred across Australia in all months, with both day and night-time temperatures increasing.This long term warming trend means that most years are now warmer than almost any observed during the 20th century.
Australia’s warmest year on record was 2019, and the seven years from 2013 to 2019 all rank among the nine warmest years.Despite the large natural year-to-year variability in Australian rainfall, underlying long-term trends are evident in some regions. For example:
The southwest and southeast of Australia have experienced drier conditions, with more frequent years of below average rainfall, especially for the cool season months of April to October.2.Cool season rainfall has been above average in western Tasmania during recent decades.
Northern Australia has been wetter across all seasons, but especially in the northwest during the northern wet season (October to April). However, rainfall variability remains high.
Australia is projected to continue to get hotter into the future, with more extremely hot days and fewer extremely cool days.Capital cities across Australia can expect a substantial increase in the number of very hot days .
Past climate change and projections of Australia’s average temperature show that 2019 (Australia’s hottest year on record) is expected to be an average year in a world where the global mean temperature is 1.5 °C above the pre-industrial baseline.
A longer fire season for the south and east and an increase in the number of days experiencing dangerous fire weather is projected.
Australia is projected to experience a decrease in cool season rainfall across many regions of the south and east, likely leading to more time spent in drought.As the climate warms, heavy rainfall is expected to become more intense throughout Australia.
Average Australian sea levels are projected to continue to rise into the future, with regional differences.As the oceans continue to warm, more frequent, intense and long-lasting marine heatwaves are projected, leading to increased risk of more frequent and severe coral bleaching events.
Fewer east coast lows are projected, particularly during the cooler months of the year.For events that do occur, sea level rise will increase the severity of some coastal impacts.
Fewer tropical cyclones are projected, but a greater proportion of those that do occur are projected to be of high intensity, with ongoing large variations from year to year.In Alpine regions, an increase in snowmelt, especially at low latitudes, is projected along with a decline in snowfall.
Conclusion
We worked with the Australian Bureau of Meteorology to produce the most comprehensive set of climate change projections for Australia ever released.
The projections are presented for eight distinct regions of Australia, each of which will be affected differently by climate change.
The projections are based on data from up to 40 global climate models, developed by institutions around the world, that were driven by four greenhouse gas and aerosol emissions scenarios. Results have been prepared for 21 climate variables (both on the land and in the ocean) and for four 20-year time periods (centered on 2030, 2050, 2070 and 2090).
Australian scientists use results from climate models that are based on established laws of physics. Confidence ratings for the projections are based on five lines of evidence.
1.Model reliability at simulating the past climate
2.Consistency between models regarding the projected magnitude and direction of change
3.Results from relevant downscaled projections
4.Evidence for plausible processes driving the simulated changes, and
5.The level of consistency with trends in the observations.
The projections draw on the full breadth of available data and peer-reviewed literature to provide a robust assessment of the potential future climate.
reference_climate:- change in australia Govt.report,CSIRO