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Professor David Karoly School of Earth Sciences, University of Melbourne Climate change: Challenges and opportunities for Gippsland.

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Presentation on theme: "Professor David Karoly School of Earth Sciences, University of Melbourne Climate change: Challenges and opportunities for Gippsland."— Presentation transcript:

1 Professor David Karoly School of Earth Sciences, University of Melbourne Climate change: Challenges and opportunities for Gippsland

2 Outline Different perspectives on climate change The latest assessment of climate change science Implications for greenhouse gas emission reduction targets globally and for Australia Challenges and opportunities for Gippsland References IPCC AR5 Climate Change 2013: The Physical Science Basis Bureau of Met & CSIRO State of the Climate 2014

3 Some views from leaders Ban Ki Moon “Climate change is the greatest threat facing humanity. It threatens to undo 50 years of our development work and it will impact the poor in the greatest sense.” Barack Obama “We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations.” Kevin Rudd: Climate change is “the greatest moral, economic and social challenge of our time”

4 Some alternative views Atmospheric scientist in Tasmania in 2014 “… we have at least to consider the possibility that the scientific establishment behind the global warming issue has been drawn into the trap of seriously overstating the climate problem - or, what is much the same thing, of seriously understating the uncertainties associated with the climate problem - in its effort to promote the cause.” Maurice Newman, chair PM's Business Advisory Council, 2013 : “The scientific delusion, the religion behind the climate crusade, is crumbling” “Australia, too, has become hostage to climate change madness”

5 Global mean temperature to 2012

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7 ‘Warming of the climate system is unequivocal, as is now evident from observations of increases in global average air and ocean temperatures, widespread melting of snow and ice, and rising global average sea level.’ (IPCC 2007) IPCC AR4 WGI FAQ 1.3

8 Glacial and inter-glacial periods On longer timescales, there have been pronounced periods of much colder temperature at regular intervals over the last million years. These ice ages are relatively stable climate states with similar total solar irradiance at the top of the atmosphere, but a much higher albedo. Global temperature decreases during past ice ages are ~5°C. Roy Soc ‘Clim change evidence & causes’ Fig 3

9 Intergovernmental Panel on Climate Change (IPCC) Joint body of UN Environment Program and World Meteorological Organization, established in 1988 Every 5-6 years, carries out a comprehensive assessment of climate change science, impacts, and approaches for mitigation and adaptation to climate change Includes representatives from all countries Fifth Assessment Report prepared by more than 600 scientists over the last three years Summaries for Policy Makers approved by consensus (including representatives of the Australian govt) at meetings in Copenhagen (Sept 13), Yokohama (Mar 14) and Berlin (Apr 14) Received the 2007 Nobel Peace Prize jointly with Al Gore

10 ‘Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia.’ ‘Each of the last three decades has been successively warmer at the Earth’s surface than any preceding decade since 1850’ (IPCC 2013) Observed changes IPCC AR5 WG1 Fig SPM.1

11 ‘Warming of the climate system is unequivocal’ IPCC AR5 WG1 Fig FAQ2.1-1 Indicators of a warming climate over the last 50 years

12 Trends in Australian climate

13 Greenhouse gas concentrations From CSIRO/BoM (2012) Concentrations in 2012 CO2 = 394 ppm, CO2-e = 476 ppm

14 ‘The atmospheric concentrations of carbon dioxide (CO 2 ), methane, and nitrous oxide have increased to levels unprecedented in at least the last 800,000 years. CO 2 concentrations have increased by 40% since pre- industrial times, primarily from fossil fuel emissions and secondarily from net land use change emissions. The ocean has absorbed about 30% of the emitted anthropogenic carbon dioxide, causing ocean acidification ’ (IPCC 2013) Observed changes IPCC AR5 Fig SPM.4

15 ‘It is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.’ (IPCC 2013) Causes of change IPCC AR5 WGI Fig SPM.6

16 ‘Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.’ (IPCC 2013) Projected changes IPCC AR5 WGI Fig SPM.7

17 ‘Global mean sea level will continue to rise during the 21st century. Under all RCP scenarios the rate of sea level rise will very likely exceed that observed during 1971–2010 due to increased ocean warming and increased loss of mass from glaciers and ice sheets.’ (IPCC 2013) IPCC AR5 WGI Fig SPM.9

18 It is virtually certain that there will be more frequent hot and fewer cold temperature extremes over most land areas on daily and seasonal timescales as global mean temperatures increase. Extreme precipitation events over most of the mid- latitude land masses and over wet tropical regions will very likely become more intense and more frequent by the end of this century, as global mean surface temperature increases. (IPCC 2013) Projected changes

19 Future climate change in Sale From Present day 2070 low emissions 2070 high emissions Ann mean temp 14.0  C1.4  C (0.9 to 1.9  C)2.6  C (1.8 to 3.7  C) Summer rainfall133 mm-3% (-16 to +10%)-6% (-28 to +19%) Winter rainfall120 mm-6% (-15 to +2%)-11% (-26 to +5%) Days over 35C5812

20 What would our changed climate be like? For a number or sites in Australia, we sought analogues for their 4C global warming climate amongst existing climates This was done based on annual maximum temperature and rainfall (with tolerances +1.0  C and +15%) Three cases were considered Least hot and wettest (10 and 90 percentiles resp. of temperature and rainfall) Mid case (50 percentiles of temperature and rainfall) Hottest and driest (90 and 10 percentiles resp. of temperature and rainfall)

21 Melbourne: Mid-case

22 Melbourne: Least hot and wettest

23 Melbourne: Hottest and driest

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25 Projected global warming Fig 5.1, The Science of Climate Change, AAS 2010 ‘Continued emissions of greenhouse gases will cause further warming and changes in all components of the climate system. Limiting climate change will require substantial and sustained reductions of greenhouse gas emissions.’ (IPCC 2013)

26 Global CO 2 emissions from fossil fuels and industry From Peters et al, 2013 Warming in 2100 ~2C BAU, Warming in 2100 >4C

27 What is needed to achieve 2°C? Transform the global energy system –Shift to low carbon energy (renewable, nuclear, carbon capture and storage - CCS) –Massive improvement in energy efficiency –Electrification of transport and heating/cooling systems Phase out use of fossil fuels, except with CCS Abatement of emissions from agriculture and industry End deforestation and increase biological storage of carbon

28 Costs to the community Human health – more heat stress, infectious diseases Natural disasters – more severe weather, bushfires and coastal flooding Agriculture – southward shift in growing regions, impacts from heat waves, some benefits from higher CO 2 Coasts – risks from sea level rise and storm surges Alpine areas – Less snow cover affecting ecosystems and tourism

29 Costs and Opportunities Climate change impacts are already affecting the economy and communities The costs of these impacts will grow rapidly in the future Reducing greenhouse gas emissions to slow climate change costs much less than the impacts There are many opportunities in Australia for new jobs and new industries in renewable energy and carbon farming

30 The Critical Decade: Key messages (2013) Australian Climate Commission Our understanding of the climate system has continued to strengthen. We are already seeing the social, economic and environmental consequences of a changing climate. Many of the risks scientists warned us about in the past are now happening. The changing climate poses substantial risks for health, property, infrastructure, agriculture and natural ecosystems. Three years into the Critical Decade it is clear: substantial progress is being made globally to reduce emissions. However, far more will need to be done to stabilise the climate. Most of the available fossil fuels cannot be burnt if we are to stabilise the climate this century.

31 From The Age, 27/3/12, permission from Tandberg “The IPCC’s new report should leave the world in no doubt about the scale and immediacy of the the threat to human survival, health and well-being.” Editorial, BMJ, 2014


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