CLIMATE CHANGE STATE OF PLAY 2024: we have entered a grim millennia of climate consequences

 

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.