State of the Climate - 2012
- Australian average temperatures are projected to rise by 1.0 to 5.0°C by 2070 when compared with the climate of recent decades.
- An increase in the number of droughts is expected in southern Australia but it also is likely that there will be an increase in intense rainfall events in many areas.
Future Australian temperature, rainfall and extreme weather events
Australian average temperatures are projected to rise by 0.6 to 1.5 °C by 2030 when compared with the climate of 1980 to 1999. The warming is projected to be in the range of 1.0 to 5.0 °C by 2070 if global greenhouse gas emissions are within the range of projected future emission scenarios considered by the Intergovernmental Panel on Climate Change. These changes will be felt through an increase in the number of hot days and warm nights, and a decline in cool days and cold nights.
Climate models suggest long-term drying over southern areas during winter and over southern and eastern areas during spring. This will be superimposed on large natural variability, so wet years are likely to become less frequent and dry years more frequent. Droughts are expected to become more frequent in southern Australia; however, periods of heavy rainfall are still likely to occur.
Models generally indicate an increase in rainfall near the equator globally, but the direction of projected changes to average rainfall over northern Australia is unclear as there is a lack of consensus among the models.
For Australia as a whole, an increase in the number of dry days is expected, but it is also likely that rainfall will be heavier during wet periods.
Projections suggest that it is likely (with more than 66 per cent probability) that there will
be fewer tropical cyclones in the Australian region, on average, but
the proportion of intense cyclones is expected to increase.
Climate change is continuing
Multiple lines of evidence show that global warming continues and that human activities are mainly responsible.
The fundamental physical and chemical processes leading to climate change are well understood. CSIRO and Bureau of Meteorology observations provide further evidence that climate change is real. The scientific understanding and the observations show that global trends in temperatures and sea-level rise since the mid-20th century have been caused predominantly by human activities. Natural climate variability also affected global-mean temperature and sea level during the past century, but much less than increasing greenhouse gases.
It is clear that increasing greenhouse gas concentrations will result in significant further global warming. Uncertainties remain regarding future levels of greenhouse gas concentrations, and the precise timing and magnitude of changes, particularly at regional scales. Further uncertainties relate to tipping points in the climate system, such as the break-up of ice-sheets, which can lead to rapid climate change. Unless greenhouse gas emissions decrease, we expect to see the temperature of the atmosphere and the oceans continue to warm and sea levels continue to rise at current or even higher rates than reported here.
CSIRO and the Bureau of Meteorology will continue to provide observations, projections, research, and analysis so that Australia’s responses are underpinned by science of the highest quality.
The Bureau of Meteorology produces an extensive range of regular climate products and reports. Some, such as rainfall, temperature and solar exposure maps, are produced daily for every State. Detailed climate statements and weather reviews are produced monthly. Special climate statements are released for significant events. Annual statements are released after each year. All of these reports, and many others, can be found on the Bureau’s website at Climate and Past Weather.
CSIRO provides comprehensive, rigorous science to help Australia understand, respond to and plan for a changing climate. Go to the Climate Change Book for a free copy of the eBook Climate Change: Science and Solutions for Australia and to CSIRO for our web page ‘Climate Questions, Science Facts’ and other information about climate science, adaptation and mitigation. Telephone 1300 363 400 or email firstname.lastname@example.org.
A list of peer-reviewed references underpinning State of the Climate 2012 can be found at Snapshot References.
The Bureau has been observing, reporting and researching Australia’s weather since 1908. CSIRO has been undertaking atmospheric and marine research for more than 60 years. Together our scientists continue to build the body of knowledge that allows people to understand the changes in our climate that we are observing and prepare for any future changes.
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