Climate change is the defining health issue of the 21st century (World Health Organization 2016).
It has significant human, environmental and economic impacts (World Health Organization 2003).
What is climate change?
Climate change is change in the world’s weather systems that occurs over decades. Recent changes in our climate are mostly caused by human activity (Department of Environment, Land, Water and Planning 2015).
Carbon dioxide and other greenhouse gases – such as methane and nitrous oxide – are generated by fossil fuel use and human agricultural practices (Watts et al. 2015).
These greenhouse gases drive heating of the atmosphere, land surface and ocean (Watts et al. 2015).
The impacts of this heating will vary across the globe but are already being seen in Australia and Victoria (Department of Environment, Land, Water and Planning 2015).
Future projections show that climate change poses an unacceptably high and potentially catastrophic risk to human health (Watts et al. 2015).
How climate change affects health
Climate change affects health directly due to more intense and frequent extreme events including heatwaves, floods, drought and bushfires (Watts et al. 2015).
It also affects health indirectly in multiple ways, such as through deteriorating air quality, changes in the spread of infectious diseases, risks to food safety and drinking and recreational water quality, and mental ill health (Watts et al. 2015).
Climate change will very likely negatively affect certain parts of the economy with increased unemployment, financial stress, food insecurity and rising social inequalities (Garnaut 2008).
Climate change will disproportionality affect the elderly, young children, pregnant women, people with a chronic disease, mental illness or disability, and people from culturally and linguistically diverse backgrounds and from low-income households (Watts et al. 2015).
The ability of infrastructure, such as hospitals, to deliver health services to the community will be increasingly affected by climate change through more frequent and extreme weather events, such as heatwaves, bushfires, floods, soil movement and sea level rise (Victorian Health and Human Services Building Authority 2018).
Public housing, housing in general, and many features of the urban environment will very likely be affected by extreme weather events (Victorian Health and Human Services Building Authority 2018).
The likely distribution of extreme heat experienced by residents in Melbourne will disproportionately affect low-income households because of poorer housing quality and reduced natural shade (Victorian Council of Social Services 2013).
While climate change itself presents a fundamental threat to health, many of the actions we can take as individuals and organisations to reduce greenhouse gas emissions can bring health benefits.
For example, increasing use of 'active transport' (such as walking and cycling) can not only reduce greenhouse gas emissions, but also help to reduce rates of obesity, diabetes, heart disease, some cancers, and musculoskeletal conditions (Department of Health and Human Services 2015).
Eating a healthy sustainable diet rich in plant-based foods, including fruits, vegetables, nuts, seeds and whole grains, and with fewer animal-based and processed foods also has improved health and environmental benefits (United Nations Food and Agriculture Organization 2006).
Climate change in Victoria
Victoria has already become warmer and drier – and these trends are likely to continue for some time into the future (Department of Environment, Land, Water and Planning 2015).
Climate-ready Victoria summarises these changes.
These Victorian climate trends will have severe impacts (Department of Health and Human Services, 2014).
For example, temperature increases lead to more frequent heatwaves, which in turn can cause heat stress, heat stroke and even death of vulnerable individuals (Department of Health and Human Services, 2014).
Increased temperatures can also result in increased risk of bushfires, with loss of life, habitat and negative impacts upon air quality (Department of Environment, Land, Water and Planning 2015; Environment Protection Authority Victoria 2018).
More frequent and more intense downpours can cause flooding, with increased risk of water-borne and vector-borne disease, infrastructure damage and loss of homes and businesses (Department of Environment, Land, Water and Planning 2015).
Less rainfall across seasons, both north and south of the Great Dividing Range, can cause drought across the state, especially in regional communities (Department of Environment, Land, Water and Planning 2015).
Drought impacts farming and food production, and increases risks to water supplies, such as through production of toxins by blooms of blue-green algae.
All of these impacts can pose serious risks to the mental and physical health of individuals and challenge the resilience of communities (Watts et al. 2015).
Victoria has already experienced significant health impacts from extremes in climate.
- the 2009 Victorian heatwave resulted in 374 excess estimated deaths and a 12 per cent increase in public hospital emergency department presentations (compared with the 5-year average) (Department of Health and Human Services 2009).
- the 2014 Victorian heat waves resulted in 167 excess estimated deaths, and resulted in a five-fold increase in heat-related public hospital emergency department presentations compared to what was expected (Department of Health and Human Services 2014)
- following the 2016–17 Victorian floods, there was a large increase in mosquitos, which resulted in a 10-fold increase in the mosquito-borne disease known as Ross River virus infection (discussed below).
Ross River virus outbreak 2016–17
In September 2016, above-average rainfall led to widespread flooding across large parts of Victoria, particularly in the north-east and north-west of the state (Lynch 2017).
Above-average rainfall was also recorded the following month in October 2016, causing the flooding to persist or reoccur in some areas (Lynch 2017).
Persistent standing water, coupled with warmer weather in the ensuing months, led to ideal mosquito breeding conditions in large parts of the state.
On-field reports from selected local government areas indicated that mosquito abundance was high (Lynch 2017).
The Department of Health and Human Services implemented an enhanced public health action plan to mitigate and manage the anticipated Ross River Virus outbreak.
This included disease surveillance and control measures, advisories for health professionals and a public messaging campaign ‘Beat the Bite’ to inform the public about the risks of mosquito-borne diseases, and to provide health advice relating to personal protective measures to avoid mosquito bites (Department of Health and Human Services 2017a and 2017b).
Despite implementing an extensive public health action plan in response to the flooding event, Victoria experienced the largest Ross River virus outbreak since 1993.
Between October 2016 and April 2017, extensive activity was documented, including 1,974 human cases (Department of Health and Human Services 2017c), seven confirmed cases in horses and several Ross River virus detections in trapped mosquitoes.
The number of human cases exceeded was nearly 10 times higher than the historical mean of 204 cases per year.
The true number of cases is thought to be several times the notified number, with each case representing a significant illness, typically characterised by joint inflammation and pain, muscle aches and fatigue, lasting weeks to months (Department of Health and Human Services 2017d).
Blue-green algal bloom 2016
Victoria is also experiencing significant impacts on its water resources.
For example, in 2016 Victoria experienced a significant blue-green algal bloom in the Murray River which lasted for 115 days (from February through to the middle of July). At its peak, the bloom spanned more than 1,330 kilometres from the Hume Dam in the East to Mildura in the West, affecting 26 drinking water treatment plans and six Victorian water agencies. (Department of Health and Human Services 2017a)
It impacted 41 Victorian townships and affected access to water for livestock and crops, as well as the tourism industry and on drinking water supplies. (Department of Health and Human Services 2017a)
In areas where drinking water-treatment plants were not capable of removing the blue-green algae, water had to be carted into the towns. Several other towns introduced Stage 4 water restrictions (Department of Health and Human Services 2017d).
The Climate Change Act
Doing nothing to address climate change will cost more than acting, and the longer the delay in acting, the more expensive the cost will become (Organisation for Economic Co-operation and Development 2015).
Victoria’s Climate Change Act 2017 provides the state with a legislative foundation to manage climate change risks and drive transition to a climate resilient community and economy.
The Act includes requirements for the Victorian Government to:
- contribute to whole of government emissions reduction in order to meet net zero emissions by 2050
- endeavour to ensure that any decision made by the Victorian Government and any policy, program or process developed or implemented appropriately takes account of climate change
- develop and implement adaptation action plans including risks and impacts on systems.
How Victoria is responding
Victoria's Climate Change Framework sets out the government’s long-term vision for climate change action (Department of Environment, Land, Water and Planning 2016).
This includes actions for all Victorian Government departments, including the Department of Health and Human Services (Department of Environment, Land, Water and Planning 2016).
The Department of Health and Human Services is undertaking comprehensive climate change planning and is preparing a climate change strategy for the department, which comprises:
- an emissions reduction plan, which will detail the scope and direction for emissions reduction in the health and human services sector
- an adaptation action plan, which will outline risks to public health and the health and human services and which identifies actions to address those risks.
The department's Environmental sustainability strategy 2018-19 to sets out the department’s commitment for the next five years to improve further the environmental sustainability of the health system (Department of Health and Human Services 2016).
It also includes actions to adapt the health system so it is resilient in the face of climate change (Victorian Health and Human Services Building Authority 2018).
Climate change and Victorian Public housing
The department is also implementing several initiatives intended to optimise thermal comfort and energy efficiency within public housing.
This includes upgrades of 1,500 low-rise public housing properties under the Energy Smart Public Housing program (Department of Health and Human Services 2017e).
7-star new build
In 2016, the Director of Housing design guidelines were updated to stipulate a preference for all-electric building designs with solar and improved energy efficiency to 7-Star NATHERS rating in new builds, where feasible (Department of Health and Human Services 2016).
This means that new public housing is being built to a higher standard than the 6-star requirement in Victoria.
The guidelines seek to optimise thermal comfort and energy efficiency for the occupants of new public housing dwellings (Department of Health and Human Services 2016).
They recommend that thermal comfort and utility costs should be considered when proposing dwelling designs, as these are key determinants of health and social outcomes for occupants.
Departmental research demonstrated that such designs increase occupant comfort, improve the environmental performance of the dwelling and reduce operating costs (Department of Health and Human Services 2016).
Climate change and the 2018 Chief Health Officer Report
In preparing this report, the Chief Health Officer seeks to highlight the significant risks to public health posed by climate change.
Wherever relevant in the report, the links between climate change and public health are explained.
Find out more
Access The Lancet article 'Health and climate change: policy responses to protect public .
The Non-communicable diseases overview contains more information about the impacts of climate change on mental health.
The department has a Climate change and health on the Better Health Channel. The page includes information and animated videos on the topics of climate change and health, extreme weather events, staying healthy in a changing climate, and actions which we can all take to reduce our impact while also improving our health.
Find out more about Ross River Virus in Victoria,
Find out more about blue-green algae.
Department of Environment, Land, Water and Planning 2015, Climate-ready Victoria, State Government of Victoria, Melbourne.
Department of Environment, Land, Water and Planning 2016, Victoria's climate change framework, State Government of Victoria, Melbourne.
Department of Health and Human Services 2009, January 2009 heatwave in Victoria: an assessment of health impacts, State Government of Victoria, Melbourne.
Department of Health and Human Services 2014, The health impacts of the January 2014 heatwave in Victoria, State Government of Victoria, Melbourne.
Department of Health and Human Services 2015, Victorian Public Health and Wellbeing Plan 2015-2019, State Government of Victoria, Melbourne.
Department of Health and Human Services 2016, Environmental sustainability strategy - Department of Health and Human Services, State Government of Victoria, Melbourne.
Department of Health and Human Services 2017a, Chief Health Officer Advisory: Health warning on mosquitoes and Ross River virus, 4 January 2017, State Government of Victoria, Melbourne.
Department of Health and Human Services 2017b, Beat the Bite information campaign, Better Health Channel, State Government of Victoria, Melbourne.
Department of Health and Human Services 2017c, Communicable disease epidemiology and surveillance Ross River virus data, State Government of Victoria, Melbourne.
Department of Health and Human Services 2017d, Annual report on drinking water quality in Victoria 2015-16, State Government of Victoria, Melbourne.Department of Health and Human Services 2017e, EnergySmart public housing project, State Government of Victoria, Melbourne.
Environment Protection Authority Victoria 2018, Air pollution in Victoria: a summary of the state of knowledge August 2018, Environment Protection Authority Victoria, Melbourne.
Garnaut R 2008, The Garnaut climate change review: final report, Cambridge University Press, Cambridge.
Gibney K 2017, Clinical and public health aspects of Ross River Virus, presentation at the Doherty Institute’s Ross River Virus Infections - current concepts event, Melbourne.
Lynch S 2017, Victorian Arbovirus Disease Control Program: vector population dynamics and arbovirus detections in the summer of 2016/17, presentation at the Doherty Institute’s Ross River Virus Infections - current concepts event, Melbourne.
Organisation for Economic Co-operation and Development 2015, the economic consequences of climate change, OECD Publishing, Paris.
United Nations Food and Agriculture Organization 2006, Livestock's long shadow: environmental issues and options, United Nations Food and Agriculture Organization, Rome.
Victorian Council of Social Service 2013, Feeling the heat: heatwaves and social vulnerability in Victoria, VCOSS, Melbourne.
Victorian Health and Human Services Building Authority 2018, Environmental sustainability strategy 2018–19 to 2022–23, State Government of Victoria, Melbourne.
Watts N, Adger W, Agnolucci P, Blackstock J, Byass P, Cai W and Costello A 2015,’ Health and climate change: policy responses to protect public health’, The Lancet, vol. 386, no. 7.
World Health Organization 2003, Health impacts of climate extremes, World Health Organization, Geneva.
World Health Organization 2016, Climate change is the defining issue for public health in the 21st century, World Health Organization, Geneva.
Reviewed 11 March 2023