Climate Change and its Effect on Safety and Infrastructure

Dr David JonesHead of Climate Analysis & Prediction

Bureau of Meteorology

Acknowledge: CSIRO, BoM, IPCC, ACE CRC, Dep Climate Change

Overview

• Why you should care about climate change

• Recent Climate Changes (focus on Australia & last 50 years):

• Human climate drivers - CO2 (the main GHG)• Temperature• Rainfall • Sea level

• Looking to the future of climate changeMost of the observed increase in globally averaged

temperatures since the mid-20th century is very likely due to the observed increase in anthropogenic

greenhouse gas concentrations (IPCC 2007)

Atmospheric CO2 and Temperature

400,000 years of data

Greenland ~3M yearsAntarctica ~13M years

~390 ppm (or 450 e-ppm)

The Human Drivers of Climate Change

Methane stabilising, NOx continuing to rise

CO2 rising rapidly

• Direct effects of climate change on individual extreme events: e.g., storms & heatwaves

• Indirect (background) effects: e.g., sea level rise exacerbating floods, higher temperatures leading to drying of forest fuels, lower fuel loads (due to winter drying)

• Effects on resilience & preparedness: e.g.,– Rural depopulation due to drought less fire fighting

volunteers?– Uncertain return period for events (leading to over/under

investment in preparedness)– Non-availability of insurance or insurance too expensive– Uncertainty delaying or stopping investment decisions– Long-term drought (or perceptions of fire risk) damaging

rural economies

Climate Change Impacts – Extremes, Safety and Infrastructure

Australian Temperatures

Temperature has increased by about 0.7 C since 19602005 was Australia’s warmest year on record, 2009 the second warmest

Annual and Decadal Mean Temperature Anomalies For Australia

-1.25

-1.00

-0.75

-0.50

-0.25

0.00

0.25

0.50

0.75

1.00

1.25

1960 1970 1980 1990 2000 2010

Year

Tem

per

atu

re A

no

mal

ies

(°C

) Decadal mean

Departures from 1961-90 normal

Changes in Maximum Temperature Extremes

Highest maximum temperatures tend to occur in recent years, with the largest number on record in 2009

Distribution of High Maximum Temperatures

0

10

20

30

40

50

60

1960 1970 1980 1990 2000Year

Nu

mb

er

in E

ac

h Y

ea

r Decadal mean

Melbourne: Mortality versus Maximum Temperature

Black Saturday (46.4°C)

Nicholls (2010)

Vic Gov (Aged Care, 2010)

Australian Rainfall

Increase in many parts of northern and central areas and decrease in the south and east

13 Years of Australian Rainfall

Recurring pattern of drought in the southwest and southeast and floods in the north and centre

Victoria: Seasonal Fire Danger

Melbourne Airport 2008/09 – second worst fire season on record. The big story is the drought.

Start of the long dry

13 year drought

Perth Dam Streamflows

From: http://www.watercorporation.com.au/D/dams_streamflow.cfm

Collapse of streamflow as a result of warming and drying

338GL

177GL 82GL

Change in Sea Level

Approximately 20cm since 1870, with a steepening riseFollows very closely global temperatures – a result of thermal expansion and melting of ice

-100

-50

0

50

100

150

1860 1880 1900 1920 1940 1960 1980 2000 2020Year

Glo

ba

l M

ea

n S

ea

Le

ve

l (m

m)

Change in Australian Sea Level

Since the early 1990s, sea level rise has been 1 to 3 cm/decade in the south and east and 7 to 10 cm/decade in the north and west

Infrastructure and Safety

Mandurah, WA

Waratah Bay, Vic

Gold Coast, QLD

~3mSome 711,000 addresses are within 3 km of the coast and within 6m of sea level (Engineers Australia)

Impact in the Coastal Zone

Increase in the frequency of high sea level events for a 0.5M sea level rise (ACE CRC 2008)

~3m

Managing our Coastal Zone in a Changing Climate (2009)If sea-levels rose by 0.9 metres, 4700 residential lots along the Lake Macquarie waterway foreshore would be inundated.

With almost 250,000 vulnerable coastal buildings, Queensland is at the highest risk from all Australian states...

In Vic, more than 80,000 coastal buildings and infrastructure are at risk from the projected sea level rise, coastal flooding and erosion.

Projections for Australia in 2030 (CSIRO & BoM)

Warmer by 0.4 to 2.0°C 10-50% increase in days over 35°C 10-80% decrease in days below 0°C Up to 10% less annual rainfall in SE Australia Up to 20% less annual rainfall in SW Australia Up to 10% more summer rainfall on east coast Up to 10% more autumn rainfall inland Heavier rainfall where average rainfall increases or decreases slightly Increase in intensity of tropical cyclones

The Future Rapid Warming Expected

+1.7ºC

600ppm

+2.7ºC

850ppm

+3.2ºC

1250ppm

Warming will be largely dictated by CO2 emissions

Emerging Consensus on Rainfall Changes

Rainfall change for 2090-2099 relative to 1980-1999.

Drying across southern Australia (and indeed most subtropical areas).

• In a country such as Australia where natural climate variability is large, the effects of climate change are more likely to manifest themselves as a series of threshold exceedences leading to stressful events and dislocation followed by (partial) recovery

• Climate change will manifest itself through the weather Expect surprises Expect unexpected emergencies and impacts It is not easy (perhaps possible) to link individual events to climate change until the climate change is large

How Will Changes Appear?

In Summary

• Data from the Bureau, CSIRO and peer organisations shows a picture of pervasive and consistent trends

• The trends are continuing and will have an escalating impact across society – health, safety, infrastructure, planning…

• The quality of the data and science is high, and the base data are all available for scrutiny and independent analysis