It been easy in recent years to take our eyes off the ball when it came to the that important predictive climate change number, the Global Surface Temperature Anomaly which tracks the degree the Earth is warming over time. So many urgent distractions - global pandemic, wars and war crimes, the local effects of rolling unnatural disasters and rising cost of living.
This is where the world, Australia, Eastern Australia and New South Wales stand in 2023......
Commonwealth Science Industrial Research Organisation (CSIRO), Climate Change In Australia, YEARS AT THE +1.5 °C GLOBAL WARMING LEVEL, retrieved 25 November 2023:
Climate variability is greater at the national and state level than in the global average, so some places have already experienced a year consistent with the what is expected to be the ‘new normal’ (the long-term average) at a +1.5 °C global warming level. Have we already seen any such years in Australia?
The answer is now yes.
The globe has warmed by around +1.1 °C, Australia by around +1.6 °C, a ratio of around x1.4. This suggests that when the world is at +1.5 °C, Australia will be at around +2.1 °C since 1850–1900. The average temperature of the record year 2019 was at around this temperature – so is expected to be typical of an average year in Australia in a +1.5 °C world. [my yellow highlighting]
ABC News, 24 November 2023:
Last week, global temperatures appeared to momentarily breach a threshold set by world governments to try and avoid widespread climate devastation.
On November 17 and 18, the world was, on average, 2 degrees Celsius warmer than pre-industrial levels for the first time in modern recorded history.
The pre-industrial period was a time before widespread fossil fuel use....
Over the past 10 months, the average global temperature was more than 1.3C above pre-industrial levels.....
Current greenhouse gas levels and emissions puts the planet on a trajectory to exceed Paris Agreement targets....
BBC News, 7 October 2023:
...BBC analysis of data from the Copernicus Climate Change Service shows that, up to 2 October, around 86 days in 2023 have been over 1.5C warmer than the pre-industrial average. That beats the 2016 record well before the end of the year.
There is some uncertainty in the exact number of days that have breached the 1.5C threshold, because the numbers reflect a global average which can come with small data discrepancies. But the margin by which 2023 has already passed 2016 figures gives confidence the record has already been broken.
"The fact that we are reaching this 1.5C anomaly daily, and for a longer number of days, is concerning," said Dr Lazenby.
One important factor in driving up these temperature anomalies is the onset of El Niño conditions.
When it comes to tracking temperature anomalies across relatively smaller areas over time, such as the eastern half of the Australian continent or the state of New South Wales, one has some indication as to why the CSIRO expects Australia to be so much hotter than the global temperature anomaly when 1.5°C is the 'normal' annual average.
Monthly maximum temperature anomalies retrieved from Australian Bureau of Meteorology (BOM) 25.11.23.
NOTE:
Anomalies denote the departure of an element from its long-period average value for the location concerned. For example, if the maximum temperature for June in Melbourne was 1 degree Celsius higher than the long-term average for this month, the anomaly would be +1 degrees Celsius. The current international standard is to use the 30 year average from 1961 to 1990 as the long-term average. (BOM, Climate Glossary 2023]
With regard to tracking climate change global surface temperature anomalies the baseline is pre-industrial temperature levels which is widely interpreted as those occurring before 1850 perhaps as early as before 1800. The United Nations IPCC uses as its reference period the years 1850–1900 to represent pre-industrial temperature.
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