What the latest IPCC report says about Australia

Parliament house flag post

What the latest IPCC report says about Australia

Posted 8/10/2013 by Anita Talberg

Since the 1900s the world has warmed an average of 0.85 degrees and the sea has risen an average of 19 cm. So affirms the 2,216-page draft report of the Intergovernmental Panel on Climate Change (IPCC) released on 27 September 2013 (see separate FlagPost on the IPCC). The first instalment of the IPCC’s Fifth Assessment Report (AR5) presents the latest science on global climate change. But Australia has a unique climate, influenced by both Indian Ocean events and the highly variable El Niño Southern Oscillation (ENSO) phenomenon. What does the latest IPCC report say about Australia?

Understanding IPCC scenarios
In order to model the climate system and propose possible futures, climatologists use a consistent set of scenarios. Scenarios are socio-economic ‘storylines’ that suggest greenhouse gas emission trajectories. These trajectories are used as inputs into computational models. In AR5 the possible futures are referred to as Representative Concentration Pathways (RCPs). RCPs are radiative forcing curves to 2100, where radiative forcing is a measure of atmospheric energy imbalances, measured in watts per square metre (W/m²). Four RCPs are used in AR5 (Table). The larger the number of watts, the hotter (on average) the world will be.
Radiative forcing
Greenhouse gas emissions in parts per million (ppm)
rises to 8.5 W/m² in 2100
rises to and stabilises at 6 W/m² in 2100
rises to and stabilises at 6 W/m² in 2100
peaks at 3 W/m² and declines to 2.6 W/m² by 2100
Australian temperatures
By mid-century (under RCP4.5) modelling suggests a median average temperature increase of 1.5 to 2⁰C over most of Australia, with that value slightly lower (1 to 1.5⁰C) along the coasts. This is compared to the 1986–2005 average. By 2100, modelling shows the temperature increase is up to 2⁰C on the coasts and 3⁰C elsewhere.
Under a worst-case scenario (RCP8.5) by 2100 average temperatures in Australia’s north are projected to rise by almost 5⁰C (and potentially up to 7⁰C) from a 1986-2005 baseline and by 4⁰C (to as much as 6⁰C) in the south.
Australian rainfall
Already, winter rainfall has decreased in southwest Western Australia and autumn rainfall has decreased in south-eastern Australia. The draft report predicts with at least 66% certainty that in future there will be less winter rain over southern Australia.
Sea level rise around Australia
AR5 confirms that a global average 19 cm sea level rise is due to two main factors: the thermal expansion of ocean water, and the melting of glaciers and ice sheets. According to AR5, it is 99% certain that sea level will continue to rise during the 21st century and beyond, even if greenhouse gas concentrations are stabilised. A global mean sea level rise of around 43 to 73 cm (compared to the 1986-2005 baseline) is projected by the end of this century.
Modelling (RCP4.5) suggests that the projected sea level rise around Australia will be consistent with global projections. However, observed sea-level rise in recent years has varied considerably around Australia. For example, the observed mean rate of sea level rise around north-western Australia of 8-10 mm per year since 1993 has been significantly higher than the global rate of 3.2 mm per year.
Australian extremes
According to AR5, by 2100 in Australia there will be more warm days and nights and fewer cold ones. Under a worst-case scenario (RCP8.5):
  • Both the coldest and hottest days of the year are predicted to be between 2 and 6⁰C hotter (depending on the region) than the 1981-2000 average.
  • The number of nights that stay above 20⁰C is expected to increase by 60 in parts of southern Australia, and by as much as 90 to 100 in eastern Queensland. This is relative to 1981-2000, for which the national average was around 80 nights per year (from Bureau of Meteorology data).
  • The number of nights that stay below 0⁰C is expected to decrease by up to 5 per year in most of southern Australia compared to 1981-2000.
Also, some extreme weather events have become more frequent and/or severe as a result of climate change, and will continue to do so. In Australia, the frequency of heat waves has increased, and AR5 predicts that there will be more droughts in southern parts of Australia.
Globally, cyclones are likely to be more intense (higher wind speeds and more rain) in the future, but their frequency is likely to either decrease or remain unchanged. Region-specific projections are not yet well quantified, so it is difficult to draw any further specific conclusions on the impacts of climate change on tropical cyclones in the Australian region.
Post co-authored by Anita Talberg and Sophie Power


  • 21/01/2014 1:45 PM
    Anita Talberg said:

    Thanks for your comment Martin. Geoscience Australia has put together a series of maps showing how sea level rise might affect Australia’s coasts. The regions that have been mapped are Sydney, the Hunter and Central Coast, Melbourne, Adelaide, South East Queensland including Brisbane and the Gold Coast, and Perth to south of Mandurah. These visualisation tools are available to the public at www.ozcoasts.gov.au. They show flooding for a specific sea level rise at high tide. Of course there are a number of caveats to keep in mind when using these maps. For example, they show simple ‘bucket fill’ flooding based on natural land surface elevation. This does not take into account sea walls, artificial coastal modifications, or other infrastructure that might slow inundation. As such, the maps are intended to provide only an indication of sea level rise impacts, not a complete picture. We don’t know about fish swimming on the restaurant table but, based on these maps, it seems that a 0.8 metre sea level rise in 2100 might see Bondi Beach narrowing somewhat; likely saltwater intrusion into the Woollahra Golf course in Rosebay; and down in Melbourne, the ports and houses by the coast will be threatened, even as far inland as Elsternwick Primary School.

  • 21/01/2014 1:45 PM
    Martin Butterfield said:

    Is there any authoritative information around about what practical effects a sea level rise of 73cm might mean? As a light hearted example, would it mean Doyles on the whaf would have fish under the table as well as on the top? Would streets in Sydney be flooded or beachside communities in the Top End be inundated?

Thank you for your comment. If it does not require moderation, it will appear shortly.
Facebook LinkedIn Twitter Add | Email Print


Flagpost is a blog on current issues of interest to members of the Australian Parliament

Parliamentary Library Logo showing Information Analysis & Advice




refugees asylum immigration Parliament Australian foreign policy elections climate change social security women welfare reform taxation Indigenous Australians Australian Defence Force welfare policy school education higher education private health insurance health financing emissions trading Senate Australian Bureau of Statistics employment people trafficking Asia statistics Middle East illicit drugs gambling health reform federal election 2010 income management Medicare disability Sport United Nations industrial relations constitution transport Australian Public Service politics criminal law Afghanistan health forced labour environment aged care aid Australian Sports Anti-Doping Agency World Anti-Doping Agency United States federal budget Carbon Pricing Mechanism dental health regulation food Fair Work Act voting law enforcement electoral reform public service reform OECD Australian Electoral Commission WADA child protection poker machines Australia in the Asian Century steroids National Disability Insurance Scheme detention 43rd Parliament slavery health system domestic violence parliamentary procedure International Women's Day accountability defence capability multiculturalism ASADA Australian Federal Police governance labour force people smuggling debt international relations New Zealand Australian Crime Commission pharmaceutical benefits scheme Human rights crime China leadership Census election results UK Parliament Papua New Guinea banking corruption pensions children's health Aviation federal election 2013 foreign debt gross debt net debt Senators and Members ALP Newstart Parenting Payment Youth Allowance sea farers Australian economy violence against women vocational education and training military history by-election political parties High Court skilled migration mental health Federal Court terrorist groups science social media Higher Education Loan Program HECS federal state relations youth paid parental leave same sex relationships coal seam gas customs planning doping health risks Gonski Review of Funding for Schooling sex slavery Special Rapporteur Northern Territory Emergency Response social policy Rural and regional trade unions Foreign affairs election timetable Indigenous royal commission Productivity United Kingdom firearms public policy Population ADRV terrorism transparency research and development welfare ASIO intelligence community Australian Security Intelligence Organisation carbon tax mining employer employee renewable energy regional unemployment fishing European Union family assistance United Nations Security Council forestry food labelling Drugs welfare systems Indonesia children Constitutional reform local government codes of conduct terrorist financing homelessness Parliamentary remuneration money laundering Trafficking in Persons Report energy social inclusion paternalism nutrition ODA Defence sitting days electoral divisions Southeast Asia administrative law universities TAFE Ireland citizenship asylum seekers early childhood education Canada Financial sector national security fuel disability employment Tasmania integrity standards NATO Australian Secret Intelligence Service sexual abuse World Trade Organization Australia public health housing affordability bulk billing water health policy Governor-General US economy export liquefied natural gas foreign bribery question time speaker superannuation public housing expertise climate Intergovernmental Panel on Climate Change Department of Agriculture Fisheries and Forestry Pacific Islands reserved seats new psychoactive substances synthetic drugs UNODC carbon markets animal health middle class welfare constitutional recognition of local government referendum consumer laws PISA competition policy US politics language education baby bonus Leaders of the Opposition citizen engagement policymaking Australia Greens servitude Trafficking Protocol forced marriage alcohol entitlements ministries Hung Parliament social citizenship maritime Iran ANZUS regional students school chaplains federal budget 2011-12 salary Medicare Locals primary care Building the Education Revolution marine pollution sustainability prisons police deaths in custody electoral margins electoral pendulum electoral redistribution redistribution NSW redistribution WA redistribution ACT electoral boundaries ASEAN Sustainable Development Goals Double dissolution Senators safety vehicles MYEFO Pathology tertiary education Taiwan Xi Ma meeting family violence government financial advisers financial planners Financial System Inquiry Murray Inquiry China; Economic policy; Southeast Asia; Africa housing Speaker; House of Representatives; Parliament High Court; Indigenous; Indigenous Australians; Native Title ACT Indigenous education Norfolk Island External Territories emissions reduction fund; climate change child care funding refugees immigration asylum procurement Indigenous health e-voting internet voting nsw state elections 44th Parliament 2015 ABS Age Pension Death penalty capital punishment execution Bali nine Bali bombings Trade EU China soft power education Fiji India Disability Support Pension Antarctica Diplomacy by-elections state and territories Bills anti-corruption fraud bribery corporate ownership whistleblower G20 economic reform innovation Members of Parliament Scottish referendum Middle East; national security; terrorism social services Criminal Code Amendment (Misrepresentation of Age to a Minor) Bill 2013 online grooming sexual assault of minors ACT Assembly smoking plain packaging tobacco cigarettes Asia; Japan; international relations Work Health and Safety Migration; asylum seekers; regional processing China; United States; international relations fiscal policy Racial Discrimination Act; social policy; human rights; indigenous Australians Foreign policy Israel Palestine asylum refugees immigration political finance donations foreign aid Economics efficiency human rights; Racial Discrimination Act employment law bullying Animal law; food copyright Australian Law Reform Commission industry peace keeping contracts workplace policies same-sex marriage disorderly conduct retirement Parliament House standing orders prime ministers First speech defence budget submarines workers Somalia GDP world heritage political engagement leave loading Trade; tariffs; safeguards; Anti-dumping public interest disclosure whistleblowing Productivity Commission limitation period cancer gene patents genetic testing suspension of standing and sessional orders live exports infant mortality honorary citizen railways disciplinary tribunals standard of proof World Health Organisation arts international students skilled graduate visas temporary employment visas apologies roads Italy national heritage NHMRC anti-dumping Rent Assistance obesity evidence law sacrament of confession US presidential election international days DFAT UN General Assembly deregulation Regulation Impact Statements small business Breaker Morant regional engagement social determinants of health abortion Members suspension workplace health and safety marine reserves hearing Victoria astronomy resources sector YMCA youth parliament Korea rebate Australian Greens presidential nomination Racial Discrimination Act political parties preselection solar hot water Financial Action Taskforce Horn of Africa peacekeeping piracy Great Barrier Reef Stronger futures political financing political education Social Inclusion Board early childhood National Quality Framework for Early Childhood Education and Care Murray-Darling Basin sanctions Norway hospitals republic President Barack Obama Presidential visits qantas counselling Korean peninsula Work Choices biosecurity hendra environmental law federalism federation preselection therapeutic goods Therapeutic Goods Administration plebiscites computer games pests suicide nuclear COAG Ministerial Councils floods ADHD stimulant medication advertising electricity extradition conscience votes poverty preventative health rural health coastal erosion Parliamentary Budget Office work-life balance

Show all
Show less
Back to top