Australian Climate Commission, April 2013
When extreme weather events occur the Climate Commission is
consistently asked questions about the link to climate change. This
report unpacks our current knowledge about different types of extreme
weather events: extreme temperatures, rainfall, drought, bushfires,
storm surges, cyclones and storms.
Download key facts from the report.
Download summary table of the report.
Download images from the report.
Watch a short video about the report.
Download quick facts for each state:
New South Wales, Victoria, Queensland,
South Australia, Western Australia, Tasmania,
Australian Captial Territiory, Northern Territiory.
1. Climate change is already increasing the intensity and
frequency of many extreme weather events, adversely affecting
Australians. Extreme events occur naturally and weather records are
broken from time to time. However, climate change is influencing these
events and record-breaking weather is becoming more common around the
world.
Some Australian examples include:
- Heat: Extreme heat is increasing across Australia. There will still
be record cold events, but hot records are now happening three times
more often than cold records.
- Bushfire weather: Extreme fire weather has increased in many parts
of Australia, including southern NSW, Victoria, Tasmania and parts of
South Australia, over the last 30 years.
- Rainfall: Heavy rainfall has increased globally. Over the last three
years Australia’s east coast has experienced several very heavy
rainfall events, fuelled by record-high surface water temperatures in
the adjacent seas.
- Drought: A long-term drying trend is affecting the southwest corner
of Western Australia, which has experienced a 15% drop in rainfall since
the mid-1970s.
- Sea-level rise: Sea level has already risen 20 cm. This means that
storm surges ride on sea levels that are higher than they were a century
ago, increasing the risk of flooding along Australia’s socially,
economically and environmentally important coastlines.
2. Climate change is making many extreme events worse in
terms of their impacts on people, property, communities and the
environment. This highlights the need to take rapid, effective action on
climate change.
- It is crucial that communities, emergency services, health and
medical services and other authorities prepare for the increases that
are already occurring in the severity and frequency of many types of
extreme weather.
- The southeast of Australia, including many of our largest population
centres, stands out as being at increased risk from many extreme
weather events – heatwaves, bushfires, heavy rainfall and sea-level
rise.
- Key food-growing regions across the southeast and the southwest are likely to experience more drought in the future.
- Some of Australia’s iconic ecosystems are threatened by climate
change. Over the past three decades the Great Barrier Reef has suffered
repeated bleaching events from underwater heatwaves. The freshwater
wetlands of Kakadu National Park are at risk from saltwater intrusion
due to rising sea level.
3. The climate system has shifted, and is continuing to
shift, changing the conditions for all weather, including extreme
weather events.
- Levels of greenhouse gases from the combustion of fossil fuels have
increased by around 40% since the beginning of the Industrial
Revolution, causing the Earth’s surface to warm significantly.
- All weather events are now occurring in global climate system that
is warmer and moister than it was 50 years ago. This has loaded the dice
towards more frequent and more severe extreme weather events.
4. There is a high risk that extreme weather events like
heatwaves, heavy rainfall, bushfires and cyclones will become even more
intense in Australia over the coming decades.
- There is little doubt that over the next few decades changes in
these extreme events will increase the risks of adverse consequences to
human health, agriculture, infrastructure and the environment.
- Stabilising the climate is like turning around a battleship – it
cannot be done immediately given its momentum. When danger is ahead you
must start turning the wheel now. Any delay means that it is more and
more difficult to avert the future danger.
- The climate system has strong momentum for further warming over the
next few decades because of the greenhouse gases that have already been
emitted, and those that will be emitted in future. This means that it is
highly likely that extreme weather events will become even more severe
in Australia over that period.
5. Only strong preventive action now and in the coming years
can stabilise the climate and halt the trend of increasing extreme
weather for our children and grandchildren.
- Averting danger requires strong preventative action. How quickly and
deeply we reduce greenhouse gas emissions will greatly influence the
severity of extreme events in the future.
- The world is already moving to tackle climate change. Ninety
countries, representing 90% of global emissions, are committed to
reducing their emissions and have programs in place to achieve this. As
the 15th largest emitter in the world, Australia has an important role
to play.
- Much more substantial action will be required if we are to stabilise
the climate by the second half of the century. Globally emissions must
be cut rapidly and deeply to nearly zero by 2050, with Australia playing
its part.
- The decisions we make this decade will largely determine the
severity of climate change and its influence on extreme events that our
grandchildren will experience. This is the critical decade to get on
with the job.
Download full report here
Author:
Climate Commission
Tags: bushfires, climate change, David Karoly, drought, extreme rainfall, extreme weather, heatwaves, high se-level events, Lesley Hughes, storms, tropical cyclones, Will Steffen
Images (press an image to enlarge)
Relationship between average and extremes (click the image to enlarge)
Climate change and the water cycle
(click the image to enlarge)Consequences of drought
(click the image to enlarge)
Measuring bushfire risk (click the image to enlarge)
Sea-level rise (click the image to enlarge)
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