Australia’s weather and climate are changing in response to a warming global climate. Global climate records are continuing to be set with 2023 the warmest year on record and Antarctic sea ice reaching record lows in the same year – and greenhouse gases are unequivocally the culprit. Key facts: Australia has warmed, on average, by 1.51 °C since national records began in 1910, with most warming occurring since 1950. Extreme heat events are increasing both in Australia and globally. Drier conditions are more frequent across the south-west and south-east of Australia. Sea surface temperatures have increased by an average of 1.08 °C since 1900. Sea levels are rising around Australia, increasing the risk of inundation and damage to coastal infrastructure and communities. Heavy short-term rainfall events are becoming more intense. The pattern of observed changes in the climate system is consistent with an increased greenhouse effect. Global carbon dioxide equivalent (CO 2 ) concentration is now around 524 parts per million, the highest in at least 2 million years. Australia’s climate is changing. Observed global changes over the 20th and 21st centuries include increases in average air and ocean temperature, rising sea levels, reduction of snow and ice cover, and changes in atmospheric and ocean circulation and regional weather patterns. These changes are caused by extra heat in the climate system due to the addition of greenhouse gases to the atmosphere. The additional greenhouse gases are primarily due to human activities such as the burning of fossil fuels (coal, oil, and natural gas), agriculture, and land clearing. These activities increase the amount of heat-trapping greenhouse gases in the atmosphere. The pattern of observed changes in the climate system is consistent with an increased greenhouse effect. Other climatic influences like volcanoes, the sun and natural variability cannot explain the timing […]