CSIRO, Bureau of Meteorology

Report at a glance

The Bureau of Meteorology and CSIRO play an important role in monitoring, analysing and communicating observed and future changes in Australia’s climate.

This fifth, biennial State of the Climate report draws on the latest monitoring, science and projection information to describe variability and changes in Australia’s climate. Observations and climate modelling paint a consistent picture of ongoing, long‑term climate change interacting with underlying natural variability.

These changes affect many Australians, particularly the changes associated with increases in the frequency or intensity of heat events, fire weather and drought. Australia will need to plan for and adapt to some level of climate change. This report is a synthesis of the science informing our understanding of climate in Australia and includes new information about Australia’s climate of the past, present and future. The science underpinning this report will help inform a range of economic, environmental and social decision‑making and local vulnerability assessments, by government, industry and communities.

Report at a glance

Key points

Australia

  • Australia’s climate has warmed by just over 1 °C since 1910, leading to an increase in the frequency of extreme heat events.
  • Oceans around Australia have warmed by around 1 °C since 1910, contributing to longer and more frequent marine heatwaves.
  • Sea levels are rising around Australia, increasing the risk of inundation.
  • The oceans around Australia are acidifying (the pH is decreasing).
  • April to October rainfall has decreased in the southwest of Australia. Across the same region May–July rainfall has seen the largest decrease, by around 20 per cent since 1970.
  • There has been a decline of around 11 per cent in April–October rainfall in the southeast of Australia since the late 1990s.
  • Rainfall has increased across parts of northern Australia since the 1970s.
  • Streamflow has decreased across southern Australia. Streamflow has increased in northern Australia where rainfall has increased.
  • There has been a long‑term increase in extreme fire weather, and in the length of the fire season, across large parts of Australia.
Report at a glance

Global

  • Concentrations of all the major long‑lived greenhouse gases in the atmosphere continue to increase, with carbon dioxide (CO2) concentrations rising above 400 ppm since 2016 and the CO2 equivalent (CO2‑e) of all gases reaching 500 ppm for the first time in at least 800,000 years.
  • Emissions from fossil fuels continue to increase and are the main contributor to the observed growth in atmospheric CO2.
  • The world’s oceans, especially in the southern hemisphere, are taking up more than 90 per cent of the extra energy stored by the planet as a result of enhanced greenhouse gas concentrations.
  • Global sea level has risen by over 20 cm since 1880, and the rate has been accelerating in recent decades.
  • Globally averaged air temperature has warmed by over 1 °C since records began in 1850, and each of the last four decades has been warmer than the previous one.
Report at a glance

Why are Australia and the Earth warming?

Energy comes from the Sun. To maintain stable temperatures at the Earth’s surface this incoming energy must be balanced in the longer‑term by an equal amount of heat radiated back to space. Greenhouse gases in the atmosphere, such as carbon dioxide and methane, make it harder for the Earth to radiate this heat, so increase the temperature of the Earth’s surface, ocean and atmosphere. This is called the greenhouse effect.

Without any greenhouse gases, the Earth’s surface would be much colder, with an average temperature of about –18 °C. For centuries prior to industrialisation the incoming sunlight and outgoing heat were balanced, and global average temperatures were relatively steady, at a little under 15 °C. Now, mostly because of the burning of fossil fuels and changes in land use, the concentrations of greenhouse gases in the atmosphere are rising and causing surface temperatures to increase, leading to an ‘enhanced’ greenhouse effect.

There is now an energy imbalance at the Earth’s surface of around 0.7–0.8 Wm–2 (averaged globally). The atmosphere and oceans will continue to warm until enough extra heat can escape to space to allow the Earth to return to balance. Because increased levels of carbon dioxide persist in the atmosphere for hundreds of years, further warming and sea level rise is inevitable.

Future climate

Watch

The biennial CSIRO and Bureau of Meteorology State of the Climate report draws on the latest monitoring, science and projection information to describe variability and changes in Australia’s climate, and how it is likely to change in the future. These changes affect many Australians, particularly changes associated with increases in the frequency or intensity of heat events, fire weather and drought.

The State of the Climate 2018 video

Read

This fifth report by the Bureau of Meteorology and CSIRO draws on the latest climate monitoring, science and projection information to describe changes and long-term trends in Australia’s climate.

State of the Climate 2018 CSIRO BOM Dec2018
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Temperature

Australia’s weather and climate continues to change in response to a warming global climate system. Australia has warmed by just over 1 °C since 1910, with most warming since 1950. This warming has seen an increase in the frequency of extreme heat events and increased the severity of drought conditions during periods of below‑average rainfall. Eight of Australia’s top ten warmest years on record have occurred since 2005.

Australia’s changing climate

Key points - Temperature

  • Australia’s climate has warmed by just over 1 °C since 1910, leading to an increase in the frequency of extreme heat events.
  • There has been a long‑term increase in extreme fire weather and in the length of the fire season across large parts of Australia since the 1950s.
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Rainfall

Australian rainfall is highly variable and is strongly influenced by phenomena such as El Niño, La Niña, and the Indian Ocean Dipole. Despite this large natural variability, underlying long‑term trends are evident in some regions. There has been a shift towards drier conditions across southwestern and southeastern Australia during April to October. Northern Australia has been wetter across all seasons, but especially in the northwest during the tropical wet season.

Australia’s changing climate

Key points - Rainfall

  • April to October rainfall across southeastern and southwestern Australia has declined.
  • Rainfall has increased across parts of northern Australia since the 1970s.
  • There is evidence that some rainfall extremes are becoming more intense.
  • Streamflow has decreased across southern Australia since the 1970s.
  • Streamflow has increased in northern Australia, since the 1970s, in places where rainfall has increased.
  • There has been a decrease in the number of tropical cyclones observed in the Australian region since 1982.
  • A downward trend in snow depth has been widely observed for Australian alpine regions since the late 1950s.
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Oceans

The ocean surface around Australia has warmed over recent decades at a similar rate to the air temperature. Sea surface temperature in the Australian region has warmed by around 1 °C since 1910, with eight of the ten warmest years on record occurring since 2010. Part of the East Australian Current now extends further south, creating an area of more rapid warming in the Tasman Sea. This extension is having numerous impacts on marine ecosystems, including many marine species extending their habitat range further south.

Oceans

Key points - Oceans

  • The ocean surface around Australia has warmed, contributing to longer and more frequent marine heatwaves.
  • The world’s oceans are taking up more than 90 per cent of the extra energy stored by the planet as a result of enhanced greenhouse gas concentrations, and the southern hemisphere oceans have taken up the majority of this heat.
  • Global sea level has risen by over 20 cm since 1880, and the rate has been accelerating in recent decades.
  • Rates of sea level rise vary around Australia.
  • The oceans around Australia are acidifying (the pH is decreasing).
  • The changes in ocean acidification have led to detectable impacts in areas such as the Great Barrier Reef.
  • The ice sheets and ice shelves of Antarctica and Greenland are losing ice due to a warmer climate; sea‑ice extent has reduced in the Arctic.

Greenhouse gases

Key points

  • Global average concentrations of all the major long‑lived greenhouse gases continue to rise in the atmosphere, with carbon dioxide concentrations rising above 400 ppm since 2016 and the CO2 equivalent of all gases reaching 500 ppm in 2017.
  • Emissions from burning fossil fuels continue to increase and are the dominant contributor to the observed growth in atmospheric CO2.

Future Climate

Australia’s national climate projections at www.climatechangeinaustralia.gov.au indicate that over coming decades Australia will experience:

  • Further increase in temperatures, with more extremely hot days and fewer extremely cool days.
  • Ongoing sea level rise.
  • Further warming and acidification of the oceans around Australia.
  • More frequent, extensive, intense and longer-lasting marine heatwaves, suggesting in turn more frequent and severe bleaching events on the Great Barrier Reef, and potentially the loss of many types of coral throughout the tropical reef systems of Australia and globally.
  • A decrease in cool-season rainfall across many regions of southern Australia, with more time spent in drought.
  • More intense heavy rainfall throughout Australia, particularly for short-duration extreme rainfall events.
  • An increase in the number of high fire weather danger days and a longer fire season for southern and eastern Australia.
  • Fewer tropical cyclones, but a greater proportion of high-intensity storms, with ongoing large variations from year to year.
Future Climate

References and data sources

General climate information and links.

References and data sources

Previous State of the Climate reports

State of the Climate 2018

The Bureau of Meteorology and CSIRO play an important role in monitoring, analysing and communicating observed changes in Australia’s climate. Read the full State of the Climate 2018 report.