trend line. Source: Australian Bureau of Meteorology.
Temperature and weather changes Australia's instrumental record from 1885 to the present shows the following broad picture: Conditions from 1885 to 1898 were generally fairly wet, though less so than in the period since 1968. The only noticeably dry years in this era were 1888 and 1897. Although some coral core data suggest that 1887 and 1890 were, with 1974, the wettest years across the continent since settlement, rainfall data for
Alice Springs, then the only major station covering the interior of the Northern Territory and Western Australia, strongly suggest that 1887 and 1890 were overall not as wet as 1974 or even 2000. In New South Wales and Queensland, however, the years 1886–1887 and 1889–1894 were indeed exceptionally wet. The heavy rainfall over this period has been linked with a major expansion of the sheep population and February 1893 saw the disastrous
1893 Brisbane flood. A drying of the climate took place from 1899 to 1921, though with some interruptions from wet
El Niño years, especially between 1915 and early 1918 and in 1920–1921, when the wheat belt of the southern interior was drenched by its heaviest winter rains on record. Two major El Niño events in 1902 and 1905 produced the two driest years across the whole continent, whilst 1919 was similarly dry in the eastern States apart from the Gippsland. The period from 1922 to 1938 was
exceptionally dry, with only 1930 having Australia-wide rainfall above the long-term mean and the Australia-wide average rainfall for these seventeen years being 15 to 20 per cent below that for other periods since 1885. This dry period is attributed in some sources to a weakening of the Southern Oscillation and in others to reduced
sea surface temperatures. Temperatures in these three periods were generally cooler than they are currently, with 1925 having the coolest minima of any year since 1910. However, the dry years of the 1920s and 1930s were also often quite warm, with 1928 and 1938 having particularly high maxima. The period from 1939 to 1967 began with an increase in rainfall: 1939, 1941 and 1942 were the first close-together group of relatively wet years since 1921. From 1943 to 1946, generally dry conditions returned, and the two decades from 1947 saw fluctuating rainfall. 1950, 1955 and 1956 were exceptionally wet except 1950 and 1956 over arid and wheatbelt regions of Western Australia. 1950 saw
extraordinary rains in central
New South Wales and most of
Queensland:
Dubbo's 1950 rainfall of can be estimated to have a
return period of
between 350 and 400 years, whilst
Lake Eyre filled for the first time in thirty years. In contrast, 1951, 1961 and 1965 were very dry, with complete monsoon failure in 1951/1952 and extreme drought in the interior during 1961 and 1965. Temperatures over this period initially fell to their lowest levels of the 20th century, with 1949 and 1956 being particularly cool, but then began a rising trend that has continued with few interruptions to the present. Since 1968, Australia's rainfall has been 15 per cent higher than between 1885 and 1967. The wettest periods have been from 1973 to 1975 and 1998 to 2001, which comprise
seven of the thirteen wettest years over the continent since 1885. Overnight minimum temperatures, especially in winter, have been markedly higher than before the 1960s, with 1973, 1980, 1988, 1991, 1998 and 2005 outstanding in this respect. There has been a marked decrease in the frequency of frost across Australia. According to the Bureau of Meteorology, Australia's annual mean temperature for 2009 was 0.9 °C above the 1961–90 average, making it the nation's second-warmest year since high-quality records began in 1910. According to the
Bureau of Meteorology's 2011 Australian Climate Statement, Australia had lower than average temperatures in 2011 as a consequence of a
La Niña weather pattern; however, "the country's 10-year average continues to demonstrate the rising trend in temperatures, with 2002–2011 likely to rank in the top two warmest 10-year periods on record for Australia, at above the long-term average". Furthermore, 2014 was Australia's third warmest year since national temperature observations commenced in 1910.
Sea level rise The Australian Government released a report saying that up to 247,600 houses are at risk from flooding from a
sea level rise of 1.1 metres. There were 39,000 buildings located within 110 metres of 'soft' erodible shorelines, at risk from a faster erosion due to sea level rise. Adaptive responses to this specific climate change threat are often incorporated in the coastal planning policies and recommendations at the state level. For instance, the
Western Australia State Coastal Planning Policy established a sea level rise benchmark for initiatives that address the problem over a 100-year period.
Water (droughts and floods) Bureau of Meteorology records since the 1860s show that a 'severe' drought has occurred in Australia, on average, once every 18 years. Australia is already the driest populated continent in the world. Rainfall in
southwestern Australia has decreased by 10–20% since the 1970s, while southeastern Australia has also experienced a moderate decline since the 1990s. Rainfall is expected to become heavier and more infrequent, as well as more common in summer rather than in winter. In June 2008 it became known that an expert panel had warned of long-term, maybe irreversible, severe ecological damage for the whole
Murray-Darling basin if it did not receive sufficient water by October of that year.
Water restrictions were in place in many regions and cities of Australia in response to chronic shortages resulting from the 2008
drought. In 2004 paleontologist
Tim Flannery predicted that unless it made drastic changes the city of
Perth, Western Australia, could become the world's first ghost
metropolis—an abandoned city with no more water to sustain its population. In 2019 the Drought and Water Resources Minister of Australia
David Littleproud, said, that he "totally accepts" the link between climate change and drought in Australia because he "lives it". He called for a reduction in
greenhouse gas emission and massive installation of renewable energy. Former leader of the
Nationals Barnaby Joyce said that if the drought became more fierce and dams were not built, the
Coalition risks "political annihilation". According to the 2022 IPCC report, there has been an increase in flooding episodes and other catastrophic weather events because of global warming. These unusual weather changes in include rainfall in the north and severe droughts in the south. Less rainfall means less streamflow of water for major cities. The IPCC recommends a step up to our adaptation and finance policies in our systems to keep up with the drastic impacts of climate change for a sustainable development.
Water resources Healthy and diverse vegetation is essential to river health and quality, and many of Australia's most important catchments are covered by native forest, maintaining a healthy ecosystem. Climate change will affect growth,
species composition and pest incursion of native species and in turn, will profoundly affect water supply from these catchments. Increased re-afforestation in cleared catchments also has the prospect for water losses. Between 1970 and 2024, 28% of Australia's Hydrological Reference Stations showed a significant decrease in streamflow while 4% showed a significant increase. • 7–35% reduction in
Melbourne's water supply.
Bushfires are exacerbated by rising temperatures and drought conditions associated with climate change. There is an increase in fire activity in Australia since 1950. Firefighting officials are concerned that the effects of climate change will increase the frequency and intensity of
bushfires under even a "low global warming" scenario. A 2006 report, prepared by CSIRO Marine and Atmospheric Research, Bushfire CRC, and the Australian Bureau of Meteorology, identified South Eastern Australia as one of the three most fire-prone areas in the world, and concluded that an increase in fire-weather risk is likely at most sites over the next several decades, including the average number of days when the
McArthur Forest Fire Danger Index rating is very high or extreme. It also found that the combined frequencies of days with very high and extreme FFDI ratings are likely to increase 4–25% by 2020 and 15–70% by 2050, and that the increase in fire-weather risk is generally largest inland. Former
Australian Greens leader,
Bob Brown said that the fires were "a sobering reminder of the need for this nation and the whole world to act and put at a priority the need to tackle climate change". The Black Saturday Royal Commission recommended that "the amount of fuel-reduction burning done on public land each year should be more than doubled". In 2018, the
fire season in Australia began in the winter. August 2018 was hotter and windier than the average. Those meteorological conditions led to a
drought in
New South Wales. The Government of the state already gave more than $1 billion to help the farmers. The hotter and drier climate led to more fires. The fire seasons in Australia are lengthening and fire events became more frequent in the latest 30 years. These trends are probably linked to climate change. The
2019–20 Australian bushfire season was by some measures Australia's "worst
bushfire season on record". In New South Wales, the fires burnt through more land than any other blazes in the past 25 years, in addition to being the state's worst bushfire season on record. NSW also experienced the longest continuously burning bushfire complex in Australia's history, having burnt more than , with flames being reported. Approximately 3 billion animals were killed or displaced by the bushfires and this made them one of the worst natural disasters in recorded history. The chance of reaching the climatic conditions that fuels the fires became more than four times bigger since the year 1900 and will become eight times more likely to occur if the temperature will rise by 2 degrees from the preindustrial level. In December 2019 the
New South Wales Government declared a
state of emergency after record-breaking temperatures and prolonged
drought exacerbated the bushfires. In 2019 bushfires linked to climate change created
air pollution 11 times higher that the hazardous level in many areas of New South Wales. Many medical groups called to protect people from "public health emergency" and moving on from fossil fuels. According to the
United Nations Environment Programme the megafires in Australia in 2019–2020 are probably linked to climate change that created the unusually dry and hot weather conditions. This is part of a global trend.
Brazil, the
United States, the
Russian Federation, and the
Democratic Republic of the Congo all face similar problems. By the second week of January the fires burned a territory of approximately 100,000 square kilometres close to the territory of England, killed one billion animals and caused large economic damage. Researchers claim that the exceptionally strong wildfires in 2019–2020 were impossible without the effects of climate change. More than one-fifth of Australian forests were burned in one season, which was completely unprecedented. They say that: "In the case of recent events in Australia, there is no doubt that the record temperatures of the past year would not be possible without anthropogenic influence, and that under a scenario where emissions continue to grow, such a year would be average by 2040 and exceptionally cool by 2060." Climate change probably also caused drier weather conditions in Australia by impacting
Indian Ocean Dipole, which also increase fires. In average, below 2% of Australian forests burn annually. Climate change has increased the likelihood of the wildfires in 2019–2020 by at least 30%, but researchers said the result is probably conservative.
Extreme weather events Rainfall patterns and the degree of droughts and storms brought about by extreme weather conditions are likely to be affected. The CSIRO predicts that a temperature rise of between 2 and 3 °C on the Australian continent could incur some of the following extreme weather occurrences, in addition to standard patterns: • Wind speeds of
tropical cyclones could intensify by 5 to 10%. • In 100 years, strong tides would increase by 12–16% along eastern Victoria's coast. • The forest fire danger indices in New South Wales and Western Australia would grow by 10% and the forest fire danger indices in south, central and north-east Australia would increase by more than 10%.
Heatwaves A report in 2014 revealed that, due to the change in climatic patterns, heat waves were found to be increasingly more frequent and severe, with an earlier start to the season and longer duration. Summer 2013–14 was warmer than average for the entirety of Australia. Both Victoria and South Australia saw record-breaking temperatures. Adelaide recorded a total of 13 days reaching 40 °C or more, 11 of which reached 42 °C or more, as well as its fifth-hottest day on record—45.1 °C on 14 January. The number of days over 40 °C beat the previous record of summer 1897–1898, when 11 days above 40 °C were recorded. Melbourne recorded six days over 40 °C, while nighttime temperatures were much warmer than usual, with some nights failing to drop below 30 °C. Overall, the summer of 2013–2014 was the third-hottest on record for Victoria, fifth-warmest on record for New South Wales, and sixth-warmest on record for South Australia. Following the 2014 event, it was predicted that temperatures might increase by up to 1.5 °C by 2030. 2015 was Australia's fifth-hottest year on record, continuing the trend of record-breaking high temperatures across the country. According to Australian
Climate Council in 2017 Australia had its warmest winter on record, in terms of average maximum temperatures, reaching nearly 2 °C above average. January 2019 was the hottest month ever in Australia with average temperatures exceeding .
Ecosystems and biodiversity has been described as the first mammal extinction due to climate change. Sustained climate change could have drastic effects on the
ecosystems of Australia. For example, rising ocean temperatures and continual erosion of the coasts from higher water levels will cause further
bleaching of the
Great Barrier Reef. Beyond that, Australia's climate will become even harsher, with more powerful tropical cyclones and longer droughts. The
Department of Climate Change said in its Climate Change Impacts and Costs fact sheet: "...ecologically rich sites, such as the Great Barrier Reef, Queensland Wet Tropics, Kakadu Wetlands, Australian Alpine areas, south-western Australia and sub- Antarctic islands are all at risk, with significant
loss of biodiversity projected to occur by 2020". It also said: "Very conservatively, 90 Australian animal species have so far been identified at risk from climate change, including mammals, insects, birds, reptiles, fish, and amphibians from all parts of Australia." Australia has some of the world's most diverse ecosystems and natural habitats, and it may be this variety that makes them the Earth's most fragile and at-risk when exposed to climate change. The Great Barrier Reef is a prime example. Over the past 20 years it has experienced unparalleled rates of
bleaching. Additional warming of 1 °C is expected to cause substantial losses of species and of associated coral communities. • 10–40% loss of principal habitat for Victoria and montane tropical vertebrate species. • 92% decrease in butterfly species' primary habitats. • 98% reduction in Bowerbird habitat in
Northern Australia. • 80% loss of freshwater wetlands in
Kakadu (30 cm sea level rise). A study conducted in 2024, suggests that worsening climate scenarios may have significant impacts on the habitat area for vertebrates and vascular plant species in Australia. This data suggests that in 2030, the habitat area among species appears consistent across climate scenarios, however, by 2090, a significant change is predicted, as deteriorating climate conditions are associated with reductions in habitat area for biodiversity.
Great Barrier Reef in the
Great Barrier Reef in 2006. The
Great Barrier Reef could be killed as a result of the rise in water temperature forecast by the IPCC. A
UNESCO World Heritage Site, the reef has experienced unprecedented rates of bleaching over the past two decades, and additional warming of only 1 °C is anticipated to cause considerable losses or contractions of species associated with coral communities. As of April 2019, approximately 5% of the coral is dead. ==Impacts on people==