Australia: State of the Climate 2022

Warming has stopped. For how long? The warmest year so far was 2019. Note that they record temperatures in decades. Differences between individual years are so slight. And note the paucity of figures. That is because the differences are in tenths of one degree, sometimes only hundredths. And the total difference between now and 1910 is tiny

Australia has warmed, on average, by 1.47 ± 0.24 °C since national records began in 1910, with most warming occurring since 1950. 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.

Australia’s warmest year on record was 2019. The eight years from 2013–20 all rank among the 10 warmest years on record. The long-term warming trend means that most years are now warmer than almost any observed during the 20th century.

Warming is observed across Australia in all months with both day and night-time temperatures increasing. This shift is accompanied by an increased number of extreme nationally averaged daily heat events across all months, including a greater frequency of very hot days in summer. For example, 2019 experienced 41 extremely warm days, about triple the highest number in any year prior to 2000. Also in 2019, there were 33 days when national daily average maximum temperatures exceeded 39 °C, a larger number than seen in the 59 years from 1960–2018 combined. Increasing trends in extreme heat are observed at locations across all of Australia. Extreme heat has caused more deaths in Australia than any other natural hazard and has major impacts on ecosystems and infrastructure.

There has also been an increase in the frequency of months that are much warmer than usual. Very high monthly maximum temperatures that occurred nearly 2 per cent of the time in 1960–89 now (2007–21) occur over 11 per cent of the time. This is about a sixfold increase over the period. Very high monthly night-time temperatures, which are also a major contributor to heat stress, occurred nearly 2 per cent of the time in 1960–89 but now occur around 10 per cent of the time.

The frequencies of extremely cold days and nights have declined across Australia. An exception is for extremely cold nights in parts of south-east and south-west Australia, which have seen significant cool season drying, and hence more clear winter nights. This results in colder nights due to increased heat loss from the ground. The frequency of frost in these parts has been relatively unchanged since the 1980s.


No comments:

Post a Comment

All comments containing Chinese characters will not be published as I do not understand them