Climate change scenarios have been published for eight clusters

The Bureau of Meteorology and the CSIRO today released the most comprehensive climate projections to date showing that unless something is done temperatures could rise by more than 5°C on average by 2090.

The projections, based on up to 40 global climate models, provide predictions for eight regions of Australia with sub-cluster information honing in on 15 areas across the country.

Overall, there is very high confidence hot days will become more frequent and hotter, according to CSIRO principal research scientist Kevin Hennessy, and it appears Australia will be hit harder than the global average.

“We also have very high confidence that sea levels will rise, oceans will become more acidic, and snow depths will decline,” Mr Hennessy said.

“We expect that extreme rainfall events across the nation are likely to become more intense, even where annual-average rainfall is projected to decline.”

Separate reports for each of eight clusters – Central Slopes, East Coast, Monsoonal North, Murray Basin, Southern Slopes, SSW Flatlands, Wet Tropics and Rangelands – give an indication of what it might be like to live in these areas as climate change effects become more pronounced.

“This research has been strongly aligned with the needs of Australia’s natural resources sector,” Mr Hennessy said. “Other researchers are using this information to assess potential impacts and management options.”

The Australian Conservation Foundation used the report to call for deep cuts to emissions, as while change until 2030 is all but locked in, a low emissions pathway could counter some of the worst predictions made for the late century under a high emissions pathway.

“We can expect Sydney’s climate to become more like Brisbane’s, Melbourne’s more like Dubbo’s, and Perth’s more like Geraldton’s,” ACF climate change program manager Victoria McKenzie-McHarg said.

“These projections show Australia will suffer more extreme heat and drought, having massive implications for agriculture, tourism, water supply and liveability. In fact, some parts of Australia could become uninhabitable.”

She said it was time for the federal government to play a constructive role in the global effort to tackle climate change.

Cluster projections

East Coast

For this cluster, which contains Sydney and Brisbane, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – projected to be around 0.4 to 1.3 °C above the climate of 1986–2005 by 2030 in all emissions scenarios
  • very high confidence of more hot days and warm spells – around two to three times the average in some areas by late in the century – and a high confidence of fewer frosts
  • medium confidence of decreases in winter rainfall for the south of the East Coast
  • high confidence of increased intensity of extreme rainfall events
  • very high confidence that mean sea level will continue to rise – 0.08 to 0.19 m above the 1986-2005 level by 2030 – and height of extreme sea-level events will also increase
  • high confidence of a harsher fire-weather climate

Southern Slopes

For this cluster, which contains Melbourne and all of Tasmania, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – projected to be around 0.4 to 1.1 °C above the climate of 1986–2005 by 2030 in all emissions scenarios
  • very high confidence of more hot days and warm spells and a high confidence of fewer frosts
  • high confidence of less rainfall in the cool season, but with strong regional differences (Tasmania is predicted to have less rain in Spring but little change or an increase in rain in winter) – changes to summer and autumn rainfall are possible but less clear
  • high confidence of increased intensity of extreme rainfall events
  • very high confidence mean sea level will continue to rise and height of extreme sea-level events will also increase – by 2030 the projected range of sea-level rise for the cluster coastline is 0.08 to 0.19 m above the 1986–2005 level
  • high confidence of a harsher fire-weather climate

SSW Flatlands

For this cluster, which contains Adelaide and Perth, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – around 0.5 to 1.1 °C above the climate of 1986-2005 by 2030
  • very high confidence of more hot days and warm spells and a high confidence of fewer frosts
  • high confidence of a continuation of the trend of decreasing winter rainfall, with spring rainfall decreases also projected with high confidence – changes in other seasons unclear
  • high confidence of more time in drought
  • very high confidence mean sea level will continue to rise – by 2030 the projected range of sea-level rise for the cluster coastline is 0.07 to 0.18 m above the 1986-2005 level – and height of extreme sea-level events will also increase
  • high confidence of a harsher fire-weather climate

Murray Basin

For this cluster, which contains Canberra, Bendigo, Mildura and Wagga Wagga, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – 0.6 to 1.3 °C above the climate of 1986–2005 by 2030
  • very high confidence of more hot days and warm spells and a high confidence of fewer frosts
  • high confidence of decreases in cool season rainfall by the end of the century and a medium confidence there will be no change in rainfall in the warm season
  • high confidence of increased intensity of extreme rainfall events
  • high confidence of a harsher fire-weather climate

Central Slopes

For this cluster, which contains Dubbo, Orange, Tamworth and Toowoomba, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – 0.6 to 1.5 °C above the climate of 1986–2005 by 2030
  • very high confidence of more hot days and warm spells, with some parts experiencing around twice the number of days above 35°C by late in the century, and a high confidence of fewer frosts
  • high confidence of decreases in winter rainfall and a medium confidence in spring decreases
  • high confidence of increased intensity of extreme rainfall events
  • medium confidence of drought increasing
  • high confidence of a harsher fire-weather climate

Monsoonal North

For this cluster, which contains Darwin and Broome, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – around 0.5 to 1.3 °C above the climate of 1986-2005 by 2030
  • very high confidence of more hot days and warm spells – for Darwin and Broome days with temperatures over 35°C could be experienced for around a third of the year under an intermediate emission scenario by late in the century
  • Changes to rainfall amounts are possible but unclear, though there is a high confidence of increased intensity of extreme rainfall events
  • very high confidence that mean sea level will continue to rise – by 2030 the projected range of sea-level rise is 0.06 to 0.17m above the 1986-2005 level – and height of extreme sea-level events will also increase
  • medium confidence of fewer but more intense tropical cyclones

Wet Tropics

For this cluster, which contains Cairns, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – around 0.3 to 1.1°C above the climate of 1986-2005 by 2030
  • very high confidence of more hot days and warm spells – for Cairns, days with temperatures over 35 °C could increase around three-fold under an intermediate emission scenario
  • Changes to rainfall amounts are possible but unclear, though there is a high confidence of increased intensity of extreme rainfall events
  • very high confidence that mean sea level will continue to rise – by 2030 the projected range of sea-level rise is 0.06 to 0.18m above the 1986-2005 level – and height of extreme sea-level events will also increase
  • medium confidence of fewer but more intense tropical cyclones

Rangelands

For this cluster, which contains Alice Springs, projections include:

  • very high confidence average temperatures will continue to increase in all seasons – around 0.6 to 1.4°C above the climate of 1986-2005 by 2030
  • very high confidence of more hot days and warm spells – for Alice Springs, days with temperatures over 35°C could occur for more than a third of the year under an intermediate emission scenario by late in the century
  • high confidence of decreases in winter rainfall, while summer changes are unclear but possible
  • high confidence of increased intensity of extreme rainfall events
  • medium confidence of more time in drought
  • very high confidence that mean sea level will continue to rise – by 2030 the projected range of sea-level rise at Port Hedland is 0.07 to 0.17m above the 1986-2005 level – and height of extreme sea-level events will also increase
  • high confidence of a harsher fire-weather climate

The reports can be downloaded from www.climatechangeinaustralia.gov.au

See here for specific cluster reports