According
to the Bureau of Meteorology and CSIRO biennial report, State
of the Climate 2024.......
Australia,
on average, has warmed by 1.51°C ± 0.23°C since national air
temperature records over the land mass of the continent began in
1910. While sea surface temperatures have increased by an average of
1.08°C since 1900.
Australia
is not so slowly and very noticeably cooking.
There
has been an increase in extreme heat events associated with the
warming over land and in the oceans.
Australia’s
warmest year on record was 2019, and 8 of the 9 warmest years on
record have occurred since 2013.
This
is what Australia's collective experience looks like expressed as a
graph
State
of the Climate 2024,
22 October 2024, p.2
Every
decade since 1950 has been warmer than preceding decades. The warming
in Australia is consistent with global trends, with the degree of
warming similar to the overall average across the world’s land
areas.
There
has been an increase in extreme fire weather, and a longer fire
season, across large parts of Australia since the 1950s. This has
resulted in catastrophic bushfires in 1967, 1974-75, 1983, 2006-07,
2009 and 2019-20. Wildfires burning across millions of hectares, changing landscapes and communities, driving many native plant and animal species closer to extinction.
The
track record with regard to rainfall has shown that:
Sustained
heavy rainfall and associated flooding in much of Australia,
particularly the east, is most common during La Niña, as illustrated
by the multiple floods that occurred in eastern Australia in 2022.
The 11 wettest years on record in eastern Australia were all influenced
by La Niña, and many of eastern Australia’s most significant flood
years, such as 1974, 2010−2011 and
2021–2022, have occurred during strong La Niña events, although
significant flooding can sometimes occur
in non-La Niña years.
Global
concentrations of all major long-lived greenhouse gases in the
atmosphere continue to increase. Global annual mean carbon dioxide
(CO2)
concentrations reached
419.2 parts per million (ppm) in 2023 and the CO2
equivalent (CO2-e)
of all greenhouse gases reached 524
ppm. These are the highest levels on Earth in at least 2 million
years.
While
global fossil fuel CO2
emissions, the principal driver of the growth in CO2
concentrations, are continuing to increase.
In
Australia the latest Quarterly Update of Australia’s NationalGreenhouse Gas Inventory: March 2024 shows emissions were 440.2 million tonnes of carbon dioxide
equivalent (Mt CO2-e)
in the year to March 2024. On a quarterly basis, this means that
national emission levels for the March quarter 2024 increased 0.6%
(0.6 Mt CO2-e)
in trend terms.
National
emissions are preliminarily estimated to be 441 Mt CO2-e
in the year to June 2024.
Actual
and trend greenhouse gas emissions have not meaningfully decreased in
the last four years according to data collated by the Department
of Climate Change, Energy, the Environment and Water.
These
inescapable global & national facts mean that Australia's future
now holds these scenarios:
Future
In
the coming decades, Australia will experience ongoing changes to its
weather and climate. The changes are projected to include:
• Continued
increase in air temperatures, with more heat extremes and fewer cold
extremes.
• Continued
decrease, on average, in cool season rainfall across many regions of
southern and eastern Australia, which will likely lead to more
time in drought.
• More
intense short-duration heavy rainfall events even in regions where
the average rainfall decreases or stays the same.
• Continued
increase in the number of dangerous fire weather days and a longer
fire season for much of southern and eastern Australia.
• Further
sea level rise and continued warming and acidification of the oceans
around Australia.
• Increased
and longer-lasting marine heatwaves that will affect marine
environments such as kelp forests and increase the likelihood of more frequent
and severe bleaching events in coral reefs around Australia,
including the Great Barrier Reef and Ningaloo Reef.
• Fewer
tropical cyclones, but with higher intensity on average, and greater
impacts when they occur
through
higher rain rates and higher sea level.
• Reduced
average snow depth in alpine regions, but with variations from year
to year.
Here
in coastal north-east New South Wales the response to our changing
climate by successive federal and state governments is: (i) to crowd
more urban development onto land that is projected to be amongst the
first dry land to experience tidal and/or permanent sea water
inundation due to rising sea levels; and (ii) to coat building
materials in heat reflecting paint while ignoring the fact that
building design is now inadequate due to the fact that the north-east
can now expect tropical hurricanes to form offshore on a 1 in 10 year
basis.
