Climate change adaptation: managing with uncertainty

1. Climate change adaptation: managing with uncertainty Climate Adaptation National Research Flagship Andrew Ash Flagship Director November 2008

2. New economic growth path Highest IPCC emission scenario All indications are that climate change will be at the top end of projections until 2030 World CO2 emissions to 2030 (GtC) *from fuel combustion and cement production Source: Sheehan, Jones et al. (forthcoming 2008) Global Environmental Change.

3. Temperature records reflect these high levels of emissions Rahmstorf et al.

4. As do sea levels - current and future rate of rise unprecedented during modern civilisation

5. The challenge is increasing every day • Emissions peak in 2020, stabilisation at 550 ppm CO2e = 6% annual reduction in emissions • Emissions peak in 2020, stabilisation at 650 ppm CO2e = 3% annual reduction in emissions

6. 2007 IPCC projections: Temperature

7. Future impacts - coasts Ongoing coastal development and population growth, in areas such as Cairns and southeast Queensland, are projected to exacerbate risks from sea-level rise and increases in the severity and frequency of storms and coastal flooding by 2050 • At Collaroy/Narrabeen beach (NSW), a sea-level rise of 0.2 m by 2050 combined with a 50-year storm event leads to coastal recession exceeding 110 m, causing losses of $245 million • The area of Cairns at risk of inundation by a 1 in 100 year storm surge is likely to more than double by 2050 IPCC 2007

8. Cost of flood events

9. Responding to the NationalChallenge • There are two points of action: mitigation (addressing the cause) and adaptation (planned response to the changes) • Mitigation of climate change refers to those response strategies that reduce the sources of greenhouse gases or enhance their sinks • Adaptation involves adjusting practices, processes and capital in response to the actuality or threat of climate change as well as changes in the decision environment such as social and institutional structures.

10. Higher impacts and adaptation later High mitigation now Low mitigation now Lower impacts and adaptation later Adaptation/mitigation see saw

11. The case for climate adaptation “The international community is too late with effective mitigation to avoid significant impacts. It may yet fail to put in place substantial mitigation, in which case the challenge of adaptation to climate change will be more daunting”. “As a nation, Australia has a high level of capacity to plan for and respond to the impacts of climate change – that is, its adaptation potential is high.” Garnaut Climate Change Review – July 2008

12. We are adapting all the time …. • Businesses re-position themselves in response to opportunities and risks • Governments change policies and programs to better achieve broad societal goals • These decisions are taken all the time – in the absence of complete information • Climate change is no different • Our aim is to help make adaptations more effective • and efficient in the face of uncertain climate changes

13. How important is climate prediction to adaptation? • Climate science has been enormously valuable in detecting and attributing recent changes in the climate system • Advances in scientific understanding and in computational resources has increased the credibility of climate models in terms of climate projections Optimal decision-making predicated on the predictive accuracy of climate models • “the effectiveness of proactive adaptation to climate change often depends on the accuracy of regional climate and impact projections, which are subject to substantial uncertainty” (Fussel 2007)

14. Demand for more certainty is increasing • Local government, planners and industry are increasingly calling for more accurate climate projections at finer scales of resolution

15. The challenge of irreducible uncertainties • Yet the accuracy of climate projections is limited by fundamental, irreducible uncertainties (Dessai et al 2008) • Climate system knowledge, chaotic processes • Uncertainty about future greenhouse gas emissions • This uncertainty in climate projections cascades when conducting impacts assessments

16. Improved use of statistics to reduce uncertainties • Combining model outputs and statistical approaches using observed trends may help in reducing uncertainties for climate projections in the timeframe of 10 to 20 years • Statistical downscaling to maintain accuracy while improving precision • More rigorous approaches to selecting climate models for use in Australia

17. Making decisions in the face of uncertainty • Decisions can be made (and are made) without accurate predictions of the future • Better to use a range of plausible scenarios combining climate projections and other factors to explore outcomes and risks • Need to include extremes in scenarios to properly assess risk

19. Using ABS/ABARE data to explore vulnerability Australian agriculture

20. Sydney Coastal region vulnerability • Spatial data essential

21. Adapting to climate change

22. Conclusion • The predict and provide approach to climate impacts and adaptation is flawed • Adaptation and decision-making will benefit more from understanding vulnerability to climate change driven by the future climate and all its uncertainties in combination with other economic, social and environmental drivers • Good economic, environmental and social data is needed to support vulnerability and adaptation and spatial data is increasingly important

23. Media enquiries: Louise Matthiesson Communication Officer CSIRO Climate Adaptation Flagship Phone: +61 7 3214 2642 Mobile: 0405 284 102 Email: louise.matthiesson@csiro.au Climate Adaptation Flagship Andrew Ash Flagship Director Phone: +61 7 32142346 Email: Andrew.Ash@csiro.au Website:www.csiro.au/org/ClimateAdaptationFlagship Thank you Contact UsPhone: 1300 363 400 Email: Enquiries@csiro.au Web: www.csiro.au