CSIRO, Bureau of Meteorology

Report at a glance

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

This fourth, biennial 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. 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 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 in both mean surface air temperature and surrounding sea surface temperature by around 1 °C since 1910.
  • The duration, frequency and intensity of extreme heat events have increased across large parts of Australia.
  • There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia since the 1970s.
  • May–July rainfall has reduced by around 19 per cent since 1970 in the southwest of Australia.
  • There has been a decline of around 11 per cent since the mid-1990s in the April–October growing season rainfall in the continental southeast.
  • Rainfall has increased across parts of northern Australia since the 1970s.
  • Oceans around Australia have warmed and ocean acidity levels have increased.
  • Sea levels have risen around Australia. The rise in mean sea level amplifies the effects of high tides and storm surges.
Report at a glance

Global

  • Global average annual carbon dioxide (CO2) levels are steadily increasing; they reached 399 parts per million (ppm) in 2015, and the annual value for 2016 is almost certain to be higher than 400 ppm. Current levels are likely the highest in the past two million years.
  • 2015 was the warmest year on record for the globe since reliable global surface air temperature records began in 1880. The last 15 years are among the 16 warmest years on record.
  • Globally-averaged ocean temperatures and heat content are increasing. Observations reveal this warming extends to at least 2000 m below the surface.
  • Globally-averaged sea level has risen over 20 cm since the late 19th century, with about one third of this rise due to ocean warming and the rest from melting land ice and changes in the amount of water stored on the land.
Report at a glance

Why are Australia and the globe warming?

Energy comes from the Sun. In order to maintain stable temperatures at the Earth’s surface, in the long run this incoming energy must be balanced by an equal amount of heat radiated back to space. Greenhouse gases in the atmosphere, such as carbon dioxide, act to increase the temperature of the Earth’s surface, ocean and the atmosphere, by making it harder for the Earth to radiate this heat. 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.

There is now an energy imbalance at the Earth’s surface of 0.65–0.80 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 carbon dioxide increases persist in the atmosphere for hundreds of years, further warming and sea-level rise is locked in.

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 2016 video

Read

This fourth 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.

Read the full State of the Climate 2016 report
Temperature icon

Temperature

Australia’s weather and climate are changing in response to a warming global climate system. Australia has warmed by around 1 °C since 1910, with most warming since 1950. Australia’s top five warmest years on record included each of the last three years—2013, 2014 and 2015; 2013 was Australia’s warmest year on record. The warming trend occurs against a background of year-to-year climate variability, mostly associated with El Niño and La Niña in the tropical Pacific Ocean.

Australia’s changing climate

Key points - Temperature

  • Australia’s climate has warmed, with around a 1 °C increase in both mean surface air temperature and surrounding sea surface temperature since 1910.
  • The duration, frequency and intensity of extreme heat events have increased across large parts of Australia.
  • The number of days per year over 35 °C has increased in recent decades, except in parts of northern Australia.
  • There has been an increase in extreme fire weather, and a longer fire season, across large parts of Australia since the 1970s.
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Rainfall

Australian rainfall varies greatly from one year to the next and from one decade to the next, and is strongly influenced by phenomena such as El Niño and La Niña. Despite this large natural variability, underlying longer-term trends are evident in some regions.

Australia’s changing climate

Key points - Rainfall

  • May–July rainfall has reduced by around 19 per cent since 1970 in the southwest of Australia.
  • There has been a decline of around 11 per cent since the mid-1990s in the April–October growing season rainfall in the continental southeast.
  • Rainfall has increased across parts of northern Australia since the 1970s.
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Oceans and Cryosphere

The oceans surrounding Australia have warmed, with the greatest surface warming to the west and south of the continent. As in the atmosphere, favourable conditions for marine heatwaves around Australia can occur due to natural variability, such as the warmer Pacific Ocean waters brought to our region by La Niña. However, attribution studies have shown that background warming of the global oceans has led to a greater prevalence of marine heatwaves. In recent years, major heat events have occurred to the west of Australia, off Tasmania’s east coast and, with the 2015–16 El Niño, in the Coral Sea.

Oceans and cryosphere

Key points - Oceans and Cryosphere

  • Ocean temperatures and ocean heat content have been steadily increasing globally.
  • The Argo global ocean observing system reveals that over the past decade ocean warming extends to a depth of at least 2000 m.
  • Globally-averaged sea level has risen over 20 cm since the late 19th century, with about one third of this rise due to ocean warming and the rest from melting land ice and changes in the amount of water stored on the land. The rise in mean sea level amplifies the effects of high tides and storm surges.
  • Oceans around Australia have become warmer and there is an increased level of acidity.

Greenhouse gases

Key points

  • Global average annual CO2 levels are steadily increasing; they reached 399 parts per million (ppm) in 2015, and the annual value for 2016 is almost certain to be higher than 400 ppm. Current levels are likely the highest in the past two million years.
  • The overwhelming contribution to the additional CO2 in the atmosphere is from human activities, mainly the burning of fossil fuels.
  • CO2 increases in 2015 were the highest ever observed, resulting from a combination of ongoing large human emissions and a weakening of land uptake of CO2 due to the 2015–16 El Niño.

Monitoring greenhouse gases at Cape Grim

Cape Grim, on Tasmania’s northwest coast, is one of only three World Meteorological Organization (WMO) global super-stations for the measurement of greenhouse gases.

This year, 2016, marks the 40th anniversary of the first greenhouse gas measurements at Cape Grim. CO2 (carbon dioxide) and CFC (chlorofluorocarbon, a potent synthetic greenhouse gas responsible for the ozone hole) measurements began in 1976 and later extended to cover all major greenhouse gases. Cape Grim’s location is unique in that its exposure to the weather systems coming across the Southern Ocean mean that about 40 per cent of the time atmospheric measurements are not influenced by local sources of pollution.

Cape Grim greenhouse gas data are freely available, and are widely used to quantify global, regional and Australian emissions of greenhouse gases. They have been used in hundreds of research papers on climate change and ozone depletion, which have been cited in all five Intergovernmental Panel on Climate Change (IPCC) international assessments of climate change and in all seven United Nations Environment Programme (UNEP)/WMO international assessments of ozone depletion. Cape Grim greenhouse gas data also provide independent verification of Australia’s National Greenhouse Gas Inventory, which reports Australia’s annual emissions to the United Nations Framework Convention on Climate Change. Cape Grim air is analysed in situ, but also in CSIRO’s GASLAB in Melbourne and in a number of laboratories around the world.

CSIRO commenced collection of the Cape Grim Air Archive in 1978; this long-running collection forms a critical component of the world’s background atmospheric air samples, underpinning extensive research on global and Australian emissions of greenhouse and ozone-depleting gases.

Greenhouse gases

References and data sources

General climate information and links.

References and data sources

State of the Climate 2016

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 2016 report