The damage from recent Cyclone Jasper has taken many, including the Bureau of Meteorology, by surprise. The failure to predict the severity of the subsequent Queensland storms has further dented their reputation, however, they still confidently predict changes to the climate due over the next 30 years!

It appears they recognise their vulnerability, as they have introduced a disclaimer notice for those who wish to use the BOM app, excluding any liability. The message reads:

To the maximum extent permitted by law, the bureau excludes any liability that may arise in connection with the BOM Weather app or any information or material presented therein or your access to or use of any of the same … this includes, but is not ­limited to, any loss, damage or cost (howsoever arising) that may be caused by any reliance on any information accessible within or via the app.

The advent of an El Niño weather pattern, with reduced cyclone incidence, had forecasters predicting a big dry.

Although only a category 2 cyclone, the massive flooding in the North inevitably led to an outbreak of ‘unprecedented’ climate change claims, now upgraded from global warming to global boiling.

Cyclones, like droughts and floods, are part of this country’s identity but still produce surprises. A look at history shows us the worst event in recent history was category 5, Cyclone Mahina in 1899. Despite a much smaller Australian population, there were over 400 deaths. Category 4 Cyclone Tracy, in 1974, was the worst in living memory, with over 70 deaths and 80 per cent of Darwin destroyed. There was no loss of life but major damage was caused by Cyclone Yasi in 2011 along with an estimated $3.6 billion inland. Yasi was also associated with Great Barrier Reef destruction and it was estimated that the reef would take 20 years to recover, but surveys show it is already in rude health.

Initially, all cyclones were given female names. In the interest of gender diversity, male names were added in 1979. So far, the LGBTQ+ movement has not demanded any non-binary equivalents. The names of cyclones now alternate, male and female, with different name lists for the Northern and Southern hemispheres.

Records show 140 category 4 or 5 cyclones occurring around Australia over the last 50 years, with no increase in frequency. Lesser categories occur around 11 times a year, more with a La Niña and less with an El Niño weather pattern when the oceans are cooler with around 4 each year make landfall. Statistics show reduced cyclone frequency in Australia associated with El Niño events, with overall slow decline over the last 40 years.

The most recent major event was category 5 Cyclone Lisa, in early 2023. It remained off the coast of Western Australia, the state with the most cyclones. Although typically confined to the North of Western Australia, the Northern Territory, and Queensland, cyclones can occasionally migrate further South. History records significant events in Melbourne in 1946, Adelaide in 1948, and Sydney in 1952.

In the Southern Hemisphere, cyclones rotate clockwise with the Coriolis effect resulting from the Earth’s revolution. They develop as low-pressure systems in the summer months, mainly between November and April, over the warm waters of the Pacific or Indian Oceans. In the Northern Hemisphere, they rotate anti-clockwise as they move away from the equator, and are known as hurricanes in the Atlantic and Typhoons in the Northern Pacific China and America are the most severely affected by these events with the top 6 countries most affected all in the North. Australia comes in at number 7 in the world.

The depth of pressure drop indicates the severity of the event, the lowest ever recorded being Typhoon Tip in 1979 when atmospheric pressure dropped to 870 hPa (normal being 1013). The lower pressures often correlate with increased air rotation around the centre, resulting windspeed being the main source of damage. As with Jasper, the uplift can carry massive amounts of water leading to flooding, there can also be damage from coastal storm surges.

In recent times the sustained wind-speed record was Typhoon Nancy in 1961, at around 350kph. Similar strength wind gusts were observed when Cyclone Monica made Australian landfall in 2006. Cyclones are categorised 1 to 5, according to sustained wind speed. Another measure of severity is the Accumulated Cyclone Energy (ACE) index, which measures the wind speed at intervals over the course of an event.

If they make landfall their speed drops rapidly, but they may last for many days.

The longest lasting was Cyclone Freddie early this year. It arose in the Indian Ocean, moving Westwards towards Africa, and lasted for 5 weeks and because of its duration, it had the highest ACE index ever recorded, at 87.

Predictions are that increasing sea temperatures, supposedly caused by CO2, should cause more severe but less frequent cyclones, they may also move further South in the Australian continent. Whilst overall numbers have declined in the Australian region, category 4 cyclones in the area have also shown a decline from a peak of 27 in the 90s to 13 in 2000s, with category 5 cyclones also failing to follow the predicted pattern, falling from a peak of 12 in the 90s to 7 in the 2000s.

Despite comments of a 15 per cent increase over 50 years, worldwide, neither the number of cyclones, nor their severity, seems to be changing, as in the graph below. Alternatively, using the ACE index as a measure of severity, there has been an increase in strength in parts of the Northern Hemisphere, but no change worldwide.

As with many climate projections, the facts fail to support the theory.

Records of worldwide storm incidence over 40 years show no increase in either minor or major events.

On retirement, atmospheric scientist William Gray, (the inventor of the ACE index and pioneer of cyclone research), took a stand against anthropogenic global warming. He believed that many climate scientists supported the theory merely to preserve their funding grants. Needless to say, this opinion resulted in numerous personal attacks, and subsequent failure of acceptance of his submissions for publication, on grounds they were ‘not up to standard’.

Article 19 of the Universal Declaration of Human Rights supports free speech, the government’s proposed ACMA legislation will increase its ability to control opinion and stifle debate. One area will be the further restriction of alternative views on climate science and its supposed influence on ‘increasing’ extreme weather events. The misleading statement ‘The science is settled’, defies the reality that the science is never settled.