heatwaves, climate change and melbourne

Heatwaves, Climate change and Melbourne

How hot is too hot?Temperatures and heatwaves

forecast to intensify (Steffen)

Melbourne climate departure is 2045 with BAU (in which the coldest years will be consistently hotter than any in the past 150 years) (Mora)

Can we slow this down?

Can we adapt?

Sources: Steffen,Climate Council (2014), Camilo Mora et al (2013), Own image / Climate Council


Fractional attribution of Risk:

“ In these simulations with only natural factors, none of the nearly 13,000 model years that we investigated exceeded our previous hottest year for Australia, recorded back in 2005.” – Sophie Lewis

Source: BOM (2014), Lewis and Karoly (2014)/The Conversation website

How hot is too hot?

2013 hottest year in Australia’s recent temperature record (BOM)


CO2 emitted by humans is main cause (IPCC)

Global Surface temperatures risen – 0.8C since 1880s (IPCC), Australian temperatures risen 0.9C since 1910 (CSIRO)

Sources: IPCC (2013), CSIRO (2014), Graph from Trenbeth & Fasullo (2013)

Rising CO2 and temperature


Ocean heat content rising

Surface temperatures rising

Sea Levels rising

Sea Ice shrinking

Ice Sheet mass loss accelerating

Sources: IPCC AR5 (2013), CSIRO (2014), Graph from CSIRO (2014)

Science on climate change is mostly settledOver 90% of heat uptake is in global oceans


Local Weather ImpactsSouth East Australia becoming

drier (long term trend - BOM)

Storms, when they do occur, will be more intense (CSIRO)

More intense and frequent heatwaves, hotspells (Steffen)

Longer fire season and more intense fire weather for bushfires (Hughes, Lucas)

Sources: Steffen (2014), Hughes (2013), Lucas et al (2007), Own image


Heatwaves amplify Urban Heat island effect

Elevated temperatures pose a threat to public health with disruption to sleep and thermoregulation resulting in heat stress.

Sources: Dan Li et al (2013), Grunstein/The Conversation (2014), Sherwood et al (2010) Image: Courtesy US EPA

• The point where temperature starts affecting sleep is about 23 degrees Celsius – results in disruption to REM sleep (Grunstein)

• Adaptable limit due to heat stress (35C for extended periods) (Sherwood)


Urban impacts of heatwaves and hotspells

Heatwaves kill more people in Australia than any other natural disaster, excluding epidemics.

Source: Australian State of the Cities Report 2013 cites Australian Emergency Management Institute


2009 Black Saturday bushfires killed 173 people.

2009 Heatwave killed 374 people (excess deaths).

Sources: Public Health Dept (2009) Graph courtesy Public Health Dept


Heat related deaths estimated to increase

Source: Graph courtesy PriceWaterhouseCoopers (2011)


Heatwaves result in Reduced work Productivity

Sources: Dunne et al (2013) Graph courtesy Dunne et al (2013)

A Study estimated:

"labour capacity reduction to less than 40% by 2200 in peak months, with most tropical and mid-latitudes experiencing extreme climatological heat stress.“ - Dunne et al (2013)


We have designed and engineered buildings, structures, public transport for certain temperature tolerances to mid 30s-low 40s, we are now exceeding these temperatures. Heatwaves may cause Cascading Infrastructure failure.

Sources: McEvoy et al (2012), Reeves et al (2010), Nguyen et al (2010), Health Dept (2009) Image from Reeves.

electricity failure and loadshedding,

public transport disruptions

Under stress: health services delivery by Ambulance, hospitals, mortuaries.


Source: Climate Institute Report on Infrastructure (2013).


Flying Fox as signature species with heat tolerance about 41-42C

Young and lactating females strongly affected.

Thousands died in 2014 Queensland heatwave (Englart)

Yarra Bend colony deaths

Other fauna, birds, plants also impacted

Sources: Welbergen et al (2008), John Englart (2014), Image Sundew/Flickr

Heatwaves impact urban ecosystems and wildlife


“The spatial distribution of heat related vulnerability in the Melbourne greater metropolitan area suggests that areas of higher risk are concentrated in the western and south-eastern regions. These are areas with a higher concentration of aged persons and households where English is not the primary language.” – Loughnan et al (2013)

Source: Mapping Heatwave Vulnerability, National Climate Change Adaptation Research Facility (NCCARF)

How vulnerable is your suburb?


The Vulnerability Index is a composite index of three risk categories: demographic, environmental and health. More info see Loughnan et al (2013) and http://www.mappingvulnerabilityindex.com/

Source: Mapping Heatwave Vulnerability, National Climate Change Adaptation Research Facility (NCCARF)


So can't we just all get air conditioners to adapt?

Air-conditioners add 1-2C of heat to the urban environment.

“The comparison between the scenarios with heat releases in the street and the baseline case without air conditioning showed a systematic increase in the street air temperature, and this increase was greater at night time than day time. It is counter-intuitive because the heat releases are higher during the day. This is due to the shallower atmospheric boundary layer during the night.” - C DeMunck et al

Sources: (deMunck et al 2012), Image: De Munck et al


Solutions?Rapid Reduction in CO2 emissions

required to stabilise temperatures (IPCC)

Need to transition: 90% of Victoria's electricity comes from brown coal (Arup)

solar PV: 6% of Moreland households 7.2% in Darebin (Englart)

Wind power is 27% capacity in SA, but less than 3% in Victoria due to draconian planning regulations (AEMO, Green)

Future Possibilities: Large scale Solar, Ocean wave, tidal, geothermal (CSIRO)

Sources: IPCC AR5, Arup (2014), Green (2013), Englart (2013), AEMO (2013), CSIRO (2012), Image John Englart


Increase Urban forest to counter urban heat island effect (MCC)

Heat alert and emergency response plan targeting vulnerable groups (see VCOSS report)

Increase insulation standards, building standards (Reeves)

Increase heat tolerances for new infrastructure, retrofit (Reeves)

Urban planning for more walking, cycling, PT (Rauland)

Sources: Melbourne City Council (2012), VCOSS (2013), Reeves et al (2010), Rauland (2013)

Climate Adaptation to heatwaves is necessary:

Heatwaves, Climate change and MelbourneSummaryClimate change is real, impacting now

Action needed by all levels of Government, business and individuals to stabilise climate for the future

We all need to reduce our carbon footprint and emissions

Going back is not an option. We can slow it down. Climate departure 2073 for Melbourne with mitigation (Mora)

need to adapt to new climates, higher temperatures and heatwaves

Avoid the unmanageable (mitigate), and manage the unavoidable (adapt)

Sources: Mora et al (2013), Image John Englart


Actions:Assess your own carbon

footprint and ways you can reduce CO2 (WWF & EPA Victoria web apps)

Lobby those in business or politics to take action. It's your future!

Educate yourself on the issues

Sign petitions, use social media

Vote wisely in elections

Source: WWF Carbon footprint calculator result

Presentation by John Englart, NMIT student, March 2014

heatwaves, climate change and melbourne

Education