Science summary
BAMOS
Jun 2020
31
Snow is falling less often according to
weather records back to 1838
Joëlle Gergis and Linden Ashcroft
Email: joelle.gergis@anu.edu.au
Note from the Editor: This article was originally published in The Conversation in June 2020.
As we slowly emerge from lock-down, local adventures are
high on people’s wish lists. You may be planning a trip to the
ski fields, or even the nearby hills to revel in the white stuff that
occasionally falls around our southern cities after an icy winter
blast.
Our new research explores these low‐elevation snowfall events.
We pieced together weather records back to 1838 to create
Australia’s longest analysis of daily temperature extremes and
their impacts on society.
These historical records can tell us a lot about Australia’s
pre‐industrial climate, before the large‐scale burning of fossil
fuels tainted global temperature records.
They also help provide a longer context to evaluate more recent
temperature extremes.
We found snow was once a regular feature of the southern
Australian climate. But as Australia continues to warm under
climate change, cold extremes are becoming less frequent and
heatwaves more common.
Extending Australia’s climate record
Data used by the Bureau of Meteorology to study long‐term
weather and climate dates back to the early 1900s. This is when
good coverage of weather stations across the country began,
and observations were taken in a standard way.
But many older weather records exist in national and state
archives and libraries, as well as local historical societies around
the country.
We analysed daily weather records from the coastal city of
Adelaide and surrounding areas, including the Adelaide Hills,
back to 1838. Adelaide is the Australian city worst affected by
heatwaves, and the capital of our nation’s driest state, South
Australia.
To crosscheck the heatwaves and cold extremes identified
in our historical temperature observations, we also looked
at newspaper accounts, model simulations of past weather
patterns, and palaeoclimate records.
The agreement was remarkable. It demonstrates the value of
historical records for improving our estimation of future climate
change risk.
Weather journal of Adelaide’s historical climate. Source: National Archives of Australia