Australasian Science: Australia's authority on science since 1938

Natural Disasters or Natural Events?

By Simon Grose

Were the weather events of the past summer truly “extreme”?

The meteorological images of Cyclone Yasi as a huge fiery maelstrom bearing down on northern Queensland evoked elemental fear responses. For those who experienced the storm and the previous tumultuous flooding in much of Queensland, and for the rest witnessing via television, fear and trepidation were the universal reactions.

Even scarier for most were the fires that seared through Perth’s suburbs this past summer and Melbourne’s hinterlands two summers ago, both erupting on days of high heat and wind after remorseless droughts.

Always in the background is the nagging knowledge of climate change, reminding us to expect more climatological chaos. No wonder we’re getting scared of weather.

“Extreme weather event” is now a part of our lexicon. This is a bit strong, given that dictionaries tell us there is nothing beyond “extreme”. There have been longer droughts and wilder floods recorded in Australia, and last year a Bureau of Meteorology study found that between 1858 and 2008 the frequency of cyclones hitting the coast between Cairns and Ballina has actually declined.

Looking back beyond white man’s history of this continent reveals evidence of even fiercer weather episodes. Palaeo-climatological research indicates that La Niña cycles, which raise the likelihood of floods and cyclones in eastern Australia, have lasted for up to 8 years in the distant past.

We may aim to learn from history and be informed by science, but our experience and emotions are powerful shapers of our perceptions and actions, so the floods, fires and cyclones of the future will be readily dubbed “extreme”.

How their frequency and ferocity influence public opinion on climate change is not as linear as some may expect. While the argument that climate change is already happening could galvanise opinion in favour of action to slow and reverse carbon emissions growth, it could also cause people to accept it and adapt because the actions necessary to reverse it are too daunting. Fight and flight are both valid responses to fear.

Fear of weather and the underlying forces of climate change may be a mark of our times, but we should not lose touch with a larger reality. What we call natural disasters are actually natural events. They are disasters because they put lives and property in jeopardy and disrupt our routines, but they are also essential to ecosystems large and small.

The floods and Yasi delivered an immense rewatering of at least half our continent after years of drought. That is no disaster. Although our planet seems immense and immutable, the lesson of climate change is that its systems are sensitive to a relatively small change in a minor gas in the atmosphere. We are privileged to be here and even luckier to know all this, even though it can be scary sometimes.