Climate change adaptation: managing with uncertainty

Climate change adaptation: managing with uncertainty

Andrew Ash

Flagship Director

November 2008

Climate Adaptation National Research Flagship

All indications are that climate change will be at the top end of projections until 2030

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4.0

8.0

12.0

16.0

20.0

1990 2000 2010 2020 2030

Source: Sheehan, Jones et al. (forthcoming 2008) Global Environmental Change.

0.02.04.06.08.0

10.012.014.016.018.020.0

1990 2000 2010 2020 2030A1 A1F1 A1T A2 B1 B2 New growth path

New economic growth path

World CO2 emissions to 2030 (GtC) *from fuel combustion and cement production

Highest IPCC emission scenario

Temperature records reflect these high levels of emissions

Rahmstorf et al.

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

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

2007 IPCC projections: Temperature

Future impacts - coasts

• 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

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

Cost of flood events

Residential & commercial costs associated with different flood events

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$50

$100

$150

$200

$250

$300

$350

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$450

$500

Probabilities of different flood events

Cost

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$Mil

lion

s

Responding to the National Challenge

• 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.

Adaptation/mitigation see saw

High mitigation now

Low mitigation now

Higher impacts and adaptation later

Lower impacts and adaptation later

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

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

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)

Demand for more certainty is increasing

• Local government, planners and industry are increasingly calling for more accurate climate projections at finer scales of resolution

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

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

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

Using ABS/ABARE data to explore vulnerability

Figure 11. The vulnerability of broadacre farming households across Australia to climate change. The map on left uses shows vulnerability to the impacts of climate change on pasture, while the map on the right shows vulnerability to climate change impacts on farm incomes.

High Moderate Low

Australian agriculture

Sydney Coastal region vulnerability

• Spatial data essential

Adapting to climate change

CopingRange

Vulnerable

Vulnerable

Stationary Climate & Coping Range

Changing Climate

Planning Horizon

CopingRange

Vulnerable

Vulnerable

Adaptation

Changing Climate Stationary Climate & Coping Range

CopingRange

Vulnerable

Vulnerable

Stationary Climate & Coping Range

Changing Climate

Planning Horizon

CopingRange

Vulnerable

Vulnerable

Adaptation

Changing Climate Stationary Climate & Coping Range

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

Thank you

Climate Adaptation FlagshipAndrew AshFlagship Director

Phone: +61 7 32142346Email: [email protected]

Contact UsPhone: 1300 363 400 Email: [email protected] Web: www.csiro.au

Media enquiries:Louise MatthiessonCommunication OfficerCSIRO Climate Adaptation Flagship

Phone: +61 7 3214 2642Mobile: 0405 284 102Email: [email protected]

Website: www.csiro.au/org/ClimateAdaptationFlagship